EP0493424B1 - Processes and devices for the heat treatment of metal wires by bringing them around capstans - Google Patents

Processes and devices for the heat treatment of metal wires by bringing them around capstans Download PDF

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Publication number
EP0493424B1
EP0493424B1 EP90913487A EP90913487A EP0493424B1 EP 0493424 B1 EP0493424 B1 EP 0493424B1 EP 90913487 A EP90913487 A EP 90913487A EP 90913487 A EP90913487 A EP 90913487A EP 0493424 B1 EP0493424 B1 EP 0493424B1
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EP
European Patent Office
Prior art keywords
capstans
wire
gas
capstan
grooves
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EP90913487A
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German (de)
French (fr)
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EP0493424A1 (en
Inventor
André Reiniche
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Compagnie Generale des Etablissements Michelin SCA
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Compagnie Generale des Etablissements Michelin SCA
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/56—Continuous furnaces for strip or wire
    • C21D9/561—Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54—Furnaces for treating strips or wire
    • C21D9/64—Patenting furnaces

Definitions

  • the invention relates to methods and devices for heat treating metal wires.
  • Such methods and devices allow for example the pearlitization of steel wires so as to obtain a fine pearlitic structure, at a high speed, for example at least equal to 15 m / s.
  • Application EP-A-275 864 describes a process for thermally treating metallic wires by passing them over discs having grooves, inside an enclosure where there is a protective gas, the heating of the wires being obtained directly by irradiation.
  • the patent US-A-2 965 368 describes a process for thermally treating metal wires by passing them through the capstan grooves which are heated internally, the wires being crossed on these capstans in contact with a protective gas.
  • the object of the invention is to provide a method and a device for heat treating a metal wire by passing the wire over capstans, so as to have at the same time a high speed of travel of the wire and good heat exchange between the wire and the capstan.
  • the invention also relates to installations for the thermal treatment of metal wires comprising at least one device according to the invention.
  • Figures 1 and 2 show a device 1 according to the invention implementing the method according to the invention.
  • This device 1 comprises two capstans 2,3 on which the wire 4 to be treated is wound.
  • the capstans 2,3 heat conductors are made for example with metallic materials.
  • the axis of rotation of the capstan 2 is referenced xx 'and the axis of the capstan 3 is referenced yy'.
  • the axes xx 'and yy' are parallel to each other and located for example in the same vertical plane.
  • Figure 1 is a section of the device 1 along the vertical plane passing through the axes xx 'and yy';
  • Figure 2 is a section of the device 1 along a vertical plane perpendicular to the axes xx 'and yy';
  • Figure 3 is a front view of the capstans 2 and 3, with the wire 4 mouflé on these capstans and
  • Figure 4 is a side view of these capstans 2 and 3 with the wire 4 mouflé on these capstans the other parts of the device 1 being assumed removed in these Figures 3 and 4.
  • the section of Figure 1 is shown schematically by the straight line segments II in Figure 2, and the section of Figure 2 is shown schematically by the straight line segments II-II in the FIG. 1.
  • the axis xx ' is represented by the letter x in FIGS. 2 and 3 and the axis yy' is represented by the letter y in FIGS. 2 and 3.
  • the wire 4 arrives, in the direction of the arrow Fa, at point 5 of the lower capstan 2 ( Figure 3).
  • the capstan 2 is actuated in rotation about the axis xx 'by a motor not shown in the drawing for the purpose of simplification, the rotation of the capstan 2 being shown diagrammatically by the arrow F2.
  • the wire 4 is driven by the capstan 2 to point 6 where it leaves the capstan 2 and goes in the direction of the arrow F2 ⁇ 3 towards the upper capstan 3 non-motorized. It makes contact at point 7 with the capstan 3 which supports it up to point 8, the rotation of the capstan 3 around the axis yy 'being shown diagrammatically by the arrow F3.
  • the wire 4 then leaves the capstan 3 and moves in the direction of the arrow F3 ⁇ 2 to the capstan 2 which it contacts at point 9.
  • the capstan 2 then drives the wire 4 once again in its rotation towards the capstan 3.
  • the hauling of the wire 4 on the capstans 2 and 3 is crossed, that is to say that the rotation F3 of the capstan 3, driven by the wire 4, is in the opposite direction to the rotation F2 of the capstan 2, the directions F2 ⁇ 3 and F3 ⁇ 2 crossing, without there being any contact between the successive portions of the wire 4 between the capstans 2 and 3.
  • This path is repeated several times, the wire 4 thus carrying out several courses in shape of eight on the two capstans 2 and 3.
  • the wire 4 finally leaves the pair of capstans 2,3 at point 10 of the lower capstan 2, in the direction of the arrow Fs (FIG. 3).
  • FIG. 5 is a section through a portion of the capstan 2, along a plane passing through the axis xx ′ of this capstan, this section being shown diagrammatically by the segments of straight lines V-V in FIG. 3.
  • This section has grooves 11, one of which is shown enlarged in Figure 6, with the wire 4 disposed in this groove, the section of Figure 6 being made along the same plane as Figure 5.
  • the capstan 2 comprises for example seven grooves 11, each of these grooves having as axis the axis xx 'of the capstan 2.
  • the width J of the groove 11 is slightly greater than the diameter D f of the wire 4, the groove 11 having a bottom 110 whose shape is a semicircle of diameter J at the Figure 6. All the grooves 11 of the capstans 2 and 3 have the same shape and the same width J.
  • the radial clearance (JD f ) / 2 and the spacing p between the grooves 11 (not the grooves) must be large enough so that the wire 4 can go from the groove 11 of a capstan to the corresponding groove 11 of the another capstan, without there being friction of the wire 4 on itself at the places where the portions of the wire 4 cross, between the capstans 2,3 (fig. 5 and 6), these values being able to be chosen by l skilled in the art depending on the application.
  • the grooves 11 of the capstan 3 not driven are located on rings 12 of axis yy '.
  • These rings which conduct heat and are made for example of metallic material are mechanically separated from the body 13 of the capstan 3 ( Figure 1).
  • the body 13 rotates freely around the axis yy 'and the rings 12 can rotate freely around the axis yy', independently of the body 13, these rings 12 sliding on the cylindrical surface 14 of the body 13.
  • the 12 rings can rotate freely with respect to each other. This arrangement improves the contact between the wire 4 and the capstan 3 and improves the tension of the wire 4 between the capstans 2, 3.
  • the heating or cooling of the capstans 2,3 is carried out by a heat conducting part, for example a metal plate 15 with two walls 16, 17 between which a heat transfer fluid 18, for example a liquid, in particular liquid, flows. water, the wall 16 being disposed on the side of the capstans 2, 3.
  • the means allowing the circulation of the fluid 18 between the walls 16, 17 are known means, comprising for example a pump, and they are not shown in the drawing in a goal of simplification.
  • the fluid 18 arrives by the tubing 19, it circulates between the walls 16, 17 then leaves the plate 15 by the tubing 20, the flow of the fluid 18 being shown diagrammatically by the arrows F18.
  • the capstans 2,3 are mounted on shafts 21 rotating in bearings 22, 23.
  • the shafts 21 pass through the walls 16, 17 and they are sealed from the fluid 18 (FIG. 1).
  • the bearings 22 are each surrounded by a sleeve 24 in which circulates a cooling fluid 25, the circulation of this fluid 25 not being shown for the purpose of simplification.
  • the fluid 25 can be the fluid 18, which is then itself a cooling fluid, the sleeve 24 then communicating with the interior of the plate 15 where the fluid 18 circulates.
  • the capstans 2,3 are placed in an enclosure 26 containing a gas 27 preferably non-oxidizing, for example hydrogen or a mixture of hydrogen and nitrogen.
  • a gas 27 preferably non-oxidizing, for example hydrogen or a mixture of hydrogen and nitrogen.
  • the heat exchanges between the capstans 2,3 and the heat transfer fluid 18 are effected by means of the gas 27 forming a layer 28, of thickness H, situated between the substantially flat face 160 of the wall 16 of a part, and each face 130, substantially planar, of the capstans 2, 3 on the other hand.
  • the faces 130 are arranged substantially in the same plane which is perpendicular to the axes xx ', yy' and substantially parallel to the face 160 which therefore partly limits the enclosure 26, the gas 27 being in contact with the capstans 2,3 and the face 160.
  • the fluid 18, if it is used is a heating fluid, the heat going from the fluid 18 to the gas 27, then from the gas 27 to the capstans 2, 3, finally from these capstans to the wire 4.
  • the fluid 18 is a cooling fluid, and the heat flows in the opposite direction, from the wire 4 to the fluid 18.
  • the gas 27 in direct contact with the plate 15 and the capstans 2,3 allows this heat exchange, the plate 15 being produced with a material conducting the heat, for example a metallic material.
  • the threaded elements 29 make it possible to vary the distance H, by moving the capstans 2,3 along their respective axes xx 'and yy'.
  • the threaded elements 29 are screwed into the female threads 30, in fixed parts 31 of the device 1.
  • the modification of the thickness H of the layer 28 of the gas 27 of thermal coupling is obtained by acting on the lever 32 which rotates the threaded elements 29, which causes an axial displacement of these threaded elements 29, this axial displacement being transmitted to the shafts 21 via the shoulders 33 machined on the shafts 21.
  • the lever 32 makes it possible to actuate simultaneously the two shafts 21 of the capstans 2,3 by known means 34, shown diagrammatically by dotted lines in FIG. 1, these means being for example a toothed belt or a chain.
  • the heat exchanges take place between the wire 4 and the capstans 2 or 3 on the one hand by direct contact along the line 35 of contact between the wire and the capstans, on the bottom 110 of the groove 11 and on the other leaves by passing through the gas 27 which is in the grooves 11 in contact with the wire 4 and the capstans 2,3, this heat flow being shown diagrammatically by the arrows F27 (FIG. 6) in the case of a cooling of the wire 4 Similarly, it would be possible to use several parts 15 in the device 1, but it is preferable to use only one, for the purpose of simplification.
  • the gas 27 When the heat treatment consists in rapidly cooling a wire of large diameter, the gas 27 must be a good conductor heat because without it, the thickness H of the layer 28 of gas 27, between the plate 15 and the capstans 2,3 could be of the same order as the dilations of the materials constituting the installation.
  • We preferably have 1 mm ⁇ H ⁇ 200 mm.
  • the gas 27 in the enclosure 26, and therefore in the layer 28, undergoes practically no other movements than those which are due to the rotation of the capstans 2,3.
  • the capstans 2,3 are placed in an enclosure 36 isolated externally by an element 37.
  • the enclosure 36 is for example equipped with electric heating elements 38 regularly distributed around its perimeter.
  • the heating elements 38 for example resistors, then make it possible to heat the capstans 2,3 when the device 1 is started and thus to obtain very rapid revivals.
  • the shafts 21 are thermally protected by heat shields 39. These elements 38 can also be used for example when the heat treatment is a heating treatment, the fluid 18 then being able not to be used.
  • FIG. 5 shows an arrangement corresponding to cooling of the wire 4 during its passage over the capstan 2, the diameter D e being greater than the diameter D s . In the case of a heating, the arrangement would be opposite with in this case D e ⁇ D s .
  • the distance E between the axes xx 'and yy' of the capstans 2,3 is as small as possible, taking into account the size of these capstans, and avoiding contact between the various portions of the wire 4 between these capstans 2.3.
  • the capstans 2,3 and the plate 15 conductors of the heat are made for example of bronze steel or cast iron.
  • FIG. 7 represents a complete installation 100 in accordance with the invention making it possible to heat treat a steel wire 4 to subject it to an austenitization treatment followed by a pearlitization treatment.
  • This complete installation 100 comprises a device 50 and six pairs of capstans referenced P1 to P6 identical to the device 1 according to the invention described above.
  • the devices P1 to P6 in accordance with the invention make it possible to cool the wire 4 or to maintain it at a practically constant temperature, the heat transfer fluid 18 being for example water.
  • the heat transfer fluid 18 being for example water.
  • FIG. 8 represents the evolution of the temperature of the wire 4 and the capstans 2,3 during a pearlitization heat treatment, the wire 4 being made of steel, the temperature T corresponding to the ordinate axis and the time "t "on the x-axis.
  • the wire 4 enters the device 50 where it undergoes an austenitization treatment.
  • This device 50 comprises two capstans 51, 52 on which the wire 4 is mouflaged, and an alternating magnetic flux is passed through the loops of wire 4 thus formed, this flux being produced by the inductor 53.
  • the wire 4 which leaves the installation 50 then arrives on the capstan 2 of the pair of capstan P1.
  • the capstans 2,3 of the pair P1 are maintained at a temperature Tc1 of the order of 450 to 650 ° C.
  • the origin 0 of the times corresponds to the arrival of the wire 4 on the pair P1.
  • the wire 4 After a time t1 of less than 4 seconds the wire 4 reaches a temperature Tf2 close to that of the capstans of the pair P1. This rapid cooling therefore allows the transformation of stable austenite into metastable austenite.
  • the wire 4 then passes successively over the four pairs P2 to P5 whose role is to maintain the wire 4 at a temperature which does not vary by more than 10 ° C by excess or by default of the given temperature Tf2, the temperature Tf of wire 4 then being for example in the interval Tf2 - 8 ° C, Tf2 + 8 ° C, and this throughout the duration of the transformation of metastable austenite into perlite and for approximately 1 to 3 seconds following this transformation.
  • the aim of this part of the installation is on the one hand to avoid recalescence during the period during which the peak of thermal power occurs due to the transformation of austenite into perlite (which would lead to the formation of coarse perlite) , on the other hand, to avoid premature cooling before the transformation is complete. Premature cooling before the transformation is complete could lead to a product containing bainite and therefore to a fragile wire and of a poor use value in particular as regards endurance.
  • the passage times of the wire 4 in the pairs P2 to P5 are respectively referenced t2 to t5, the temperatures of the capstans of the pairs P2 to P5 are respectively referenced Tc2 in Tc5.
  • the sum t2 + t3 + t4 + t5 is for example of the order of 4 to 10 seconds.
  • Figure 9 shows the evolution of the transformation of austenite into perlite over time.
  • the time "t" corresponds to the abscissa axis, and the% of transformation into perlite to the ordinate axis.
  • the transformation during the time t2 is slow, the perlitization starting only towards the end of this time t2, the power to be exchanged is therefore low and the temperature Tc2 of the second pair P2 is slightly lower than the target temperature for the transformation (Tf2 ).
  • the transformation during the time t3 is very rapid, the power to be exchanged is therefore greater, and the temperature Tc3 of the third pair P3 is significantly lower than the temperature Tc2 of the second pair P2.
  • the transformation during time t4 occurs at a speed substantially identical to that of time t2, the temperature Tc4 of the fourth pair P4 is therefore very close to Tc2.
  • the temperature Tc paire of the fifth pair P5 is therefore substantially equal to Tf2.
  • the purpose of this temperature maintenance during the time t5 being to ensure that the transformation into perlite is completed before the cooling corresponding to the time t6.
  • K1 L1 / (JxD f - Df2)
  • K2 From / E (6)
  • K3 100 (De / Ds - 1)
  • K4 (VxD f 2xH) / (L2 xDe2) (8)
  • L1 is the thermal conductivity of the gas which is in the grooves 11 in contact with the wire 4 and the capstans 2
  • L2 is the thermal conductivity of the gas constituting the layer 28 of gas 27, these conductivities L1 and L2 being determined at 600 ° C and expressed in watts.m ⁇ 1.
  • L1 and L2 are identical, and represented by L; D f is the diameter of the wire expressed in millimeters; J is the width of the grooves 11 expressed in millimeters; E is the distance between the capstans expressed in millimeters; D e is the winding diameter of the wire 4 at the entry of any capstan 2,3; D s is the winding diameter of the wire 4 at the outlet of the same capstan, D e and D s being expressed in millimeters; V is the wire running speed expressed in meters per second; H is the thickness of the layer 28 of the gas 27, expressed in millimeters.
  • the following relationships are furthermore verified in at least one of the pairs P2 to P4 K1 ⁇ 0.3 (11) 0.5x10 ⁇ 3 ⁇ K4 ⁇ 9x10 ⁇ 3 (12).
  • the isothermicity obtained during phases t2 to t5 can only be improved if the number of elements used is greater than 4 but this leads to a higher investment which is not necessary to obtain on the one hand an isothermicity at ⁇ 8 ° C, on the other hand the quality of the advertised wire.
  • the final cooling section allows the cooling of the wire from a temperature Tf2 of the order of 450 to 650 ° C to a temperature Tf3 of the order of 100 to 200 ° C in a time t6 of the order of 3 to 6 seconds, it includes a pair of crossed hauled capstans, the lower capstan 2 is motorized, the upper capstan 3 is not, the winding diameter D e on the first groove of the lower capstan is greater than the diameter Ds of the last groove of the lower capstan, the capstans are maintained at a temperature Tc6 of the order of 50 to 150 ° C.
  • the composition of the steels used is given in Table 1 TABLE 1 Type VS Mn Yes S P Al It Cr Or 1 0.70 0.61 0.22 0.028 0.018 0.084 0.048 0.061 0.016 2 0.82 0.69 0.20 0.026 0.019 0.082 0.043 0.058 0.015 ( Figures correspond to% by weight)
  • the characteristics of this steel are as follows: Thermal conductivity at 500 ° C: 19 wm ⁇ 1. ° K ⁇ 1 Thermal expansion at 400 ° C: 17.10 ⁇ 6m.m ⁇ 1.
  • the recovery rate T r is the ratio between the length of wire in contact with the groove bottoms and the total length of wire located between the first point of contact 5 on arrival on the heat transfer element and the last point 10 at the outlet, that is to say between points 5 and 10 previously defined ( Figure 3).
  • the incubation time is the time necessary for 1% of metastable austenite to transform into perlite, this time being counted from the beginning of the cooling (arrival of the wire 4 on the pair P1).
  • the transformation time is the time necessary to go from 1% to 99% of perlite.
  • Residence time: t3 1.26 seconds Number of turns: 3 The wire temperature was maintained at 580 ⁇ 6 ° C.
  • the capstans were kept at a temperature of: 417 ° C using a water flow at 25 ° C of: 0.7 m3 / h.
  • the capstans were kept at a temperature of: 585 ⁇ 5 ° C thanks to the electrical resistances 38, the water circulation was cut off.
  • This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel.
  • the incubation time and the transformation time are substantially the same as in previous example.
  • the wire After heat treatment, the wire has a tensile strength of 1350 MPa.
  • This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.17 mm.
  • the capstans were kept at a temperature of: 585 ⁇ 5 ° C thanks to the electrical resistances 38, the water circulation was cut off.
  • This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.28 mm.
  • This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel.
  • the incubation time and the transformation time are substantially the same as in previous example.
  • the wire After heat treatment, the wire has a tensile breaking strength of 1345 MPa.
  • This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.28 mm.
  • This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.35 mm.
  • This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel.
  • the incubation time and the transformation time are substantially the same as in previous example.
  • the wire After heat treatment, the wire has a tensile strength of 1355 MPa.
  • This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.35 mm.
  • Example 2 This example is identical to Example 1 with the exception that a type 1 steel is used from the composition point of view but with an incubation time of 3.8 seconds and a transformation time of 3, 8 seconds at 580 ° C.
  • the installation is identical to that used for Example 1 except for the number of turns which went from 7 to 8 on the first pair P1 of capstans, from 3 to 4 on the third pair P3 of capstans.
  • Example 6 This example is identical to Example 6 except that a type 2 steel is used from the composition point of view but with an incubation time of 4.4 seconds and a transformation time of 6 seconds. at 580 ° C.
  • the installation is identical to that of Example 6 except for the number of turns which went from 4 to 5 on the first P1 pair of capstans, from 2 to 3 on the third P3 pair of capstans.
  • Example 2 is identical to Example 2 except for the fact that a type 2 steel is used from the composition point of view but with an incubation time of 4 seconds and a transformation time of 3 seconds at 580 ° C.
  • the automatic regulation put the second pair P2 of capstans in heating mode, that is to say that the cooling water circulation was cut off and the electric heating resistors 38 were put into service. so as to avoid the cooling of the wire which would have occurred on the second pair of capstans between the arrival of the wire and the moment when it is the seat of a release of heat due to the transformation of the austenite into perlite .
  • the tensile strengths after heat treatment and after wire drawing decreased by less than 2% compared to those of Example 2, which is due to the fact of a slightly poorer isothermicity.
  • the adaptability can be improved by improving the isothermicity, that is to say by increasing the number of pairs of capstans, but the small gain in resistance of the wire which one can expect from it does not generally justify the expense. performed.
  • the wire 4 treated in accordance with the invention in the installation 100 has the same structure as that obtained by the known lead patenting process, that is to say a fine pearlitic structure.
  • This structure includes cementite lamellae separated by ferrite lamellae.
  • FIG. 10 represents in section a portion 70 of such a fine pearlitic structure.
  • This portion 70 comprises two substantially parallel cementite strips 71, separated by a ferrite strip 72.
  • the thickness of the cementite strips 71 is represented by "i” and the thickness of the ferrite strips 72 is represented by "e” .
  • the pearlitic structure is fine, that is to say that the average value of the sum i + e is at most equal to 1000 ⁇ , with a standard deviation of 250 ⁇ .

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Abstract

Process and device (1) for the heat treatment of at least one metal wire (4) using capstans (2, 3) characterised by the following features: a) the wire (4) is brought around at least two capstans (2, 3) which conduct the heat and which include recesses (11). The wire (4) is reeved and crossed in said recesses (11), the width of the recesses (11) being slightly greater than that of the wire (4); b) the capstans (2, 3) are heated or cooled by means of at least one gas (27), which passes between the capstans and a part which is in contact with a heat exchanging fluid; c) the thickness of the gas layer is chosen according to the heat treatment to be applied. Installations for the heat treatment of metal wires (4) include at least one device (1), metal wires (4) treated by the process and/or the device (1), and/or the installations according to the invention, as well as items reinforced by said wires (4), in particular tyre treads.

Description

L'invention concerne les procédés et les dispositifs permettant de traiter thermiquement des fils métalliques. De tels procédés et dispositifs permettent par exemple la perlitisation de fils d'acier de façon à obtenir une structure perlitique fine, à une vitesse importante, par exemple au moins égale à 15 m/s.The invention relates to methods and devices for heat treating metal wires. Such methods and devices allow for example the pearlitization of steel wires so as to obtain a fine pearlitic structure, at a high speed, for example at least equal to 15 m / s.

Il est connu par le brevet SU-A-1 224 347 d'effectuer un traitement de perlitisation en faissant passer un fil d'acier sur des cabestans lisses placés dans l'air ambiant, de façon à effectuer ce traitement à une vitesse notablement plus élevée que dans une installation classique de patentage au plomb, et sans avoir les inconvénients de cette technique au plomb, qui sont notamment les dangers concernant l'hygiène et la protection de l'environnement. L'expérience montre que le procédé décrit dans ce brevet conduit à l'obtention de produits ayant une valeur d'usage nettement moins bonne que celle que l'on peut obtenir avec le patentage au plomb. En effet la courbe de refroidissement comporte une zone de recalescence importante, par exemple une remontée de température de 50°C pour des fils ayant un diamètre de 3 mm. Cette recalescence importante est due au mauvais coefficient de transfert thermique entre le fil et le cabestan, qui conduit à un écart de température important entre le fil et le cabestan lorsque la pointe de puissance thermique provoquée par la transformation de l'austénite en perlite se produit. Or la présence d'une recalescence supérieure à 20°C au cours du traitement thermique ne permet pas d'obtenir une valeur d'usage élevée des fils, en particulier lorsqu'ils ont des diamètres importants.It is known from patent SU-A-1 224 347 to carry out a pearlitization treatment by passing a steel wire over smooth capstans placed in the ambient air, so as to carry out this treatment at a speed noticeably more high than in a conventional lead patenting installation, and without having the drawbacks of this lead technique, which are in particular the dangers relating to hygiene and environmental protection. Experience shows that the process described in this patent leads to the production of products having a clearly lower use value than that which can be obtained with lead patenting. In fact, the cooling curve includes a significant recalescence zone, for example a rise in temperature of 50 ° C. for wires having a diameter of 3 mm. This significant recalescence is due to the poor coefficient of heat transfer between the wire and the capstan, which leads to a significant temperature difference between the wire and the capstan when the peak of thermal power caused by the transformation of austenite into perlite occurs. . However, the presence of a recalescence greater than 20 ° C. during the heat treatment does not make it possible to obtain a high use value of the wires, in particular when they have large diameters.

La demande EP-A-275 864 décrit un procédé pour traiter thermiquement des fils métalliques en les faisant passer sur des disques comportant des gorges, à l'intérieur d'une enceinte où se trouve un gaz protecteur, le chauffage des fils étant obtenu directement par irradiation.Application EP-A-275 864 describes a process for thermally treating metallic wires by passing them over discs having grooves, inside an enclosure where there is a protective gas, the heating of the wires being obtained directly by irradiation.

Le brevet US-A-2 965 368 décrit un procédé pour traiter thermiquement des fils métalliques en les faisant passer dans les gorges de cabestans qui sont chauffés intérieurement, les fils étant mouflés croisés sur ces cabestans au contact d'un gaz protecteur.The patent US-A-2 965 368 describes a process for thermally treating metal wires by passing them through the capstan grooves which are heated internally, the wires being crossed on these capstans in contact with a protective gas.

Le but de l'invention est de proposer un procédé et un dispositif permettant de traiter thermiquement un fil métallique en faisant passer le fil sur des cabestans, de façon à avoir en même temps une vitesse importante de défilement du fil et un bon échange thermique entre le fil et le cabestan.The object of the invention is to provide a method and a device for heat treating a metal wire by passing the wire over capstans, so as to have at the same time a high speed of travel of the wire and good heat exchange between the wire and the capstan.

En conséquence l'invention concerne un procédé permettant de traiter thermiquement au moins un fil métallique à l'aide de cabestans, dans lequel on fait passer le fil sur au moins deux cabestans conduisant la chaleur comportant des gorges, le fil étant mouflé, croisé dans ces gorges, la largeur des gorges étant légèrement supérieure à celle du fil, un gaz, dans les gorges, étant au contact du fil et des cabestans ;
ce procédé étant caractérisé par les points suivants :

  • a) on chauffe ou on refroidit les cabestans par l'intermédiaire du gaz disposé également entre les cabestans et au moins une pièce, ce gaz étant au contact des cabestans et de la pièce, cette pièce qui conduit la chaleur, étant située à l'extérieur des cabestans, en faisant circuler un fluide caloporteur autre que le gaz au contact de la pièce, afin que des échanges thermiques s'effectuent d'une part entre le gaz et la pièce et d'autre part entre la pièce et le fluide ;
  • b) on règle l'épaisseur de la couche de gaz, entre les cabestans et la pièce, en fonction du traitement thermique à effectuer.
Consequently, the invention relates to a method making it possible to heat treat at least one metal wire using capstans, in which the wire is passed over at least two heat conducting capstans comprising grooves, the wire being reeled, crossed in these grooves, the width of the grooves being slightly greater than that of the wire, a gas in the grooves being in contact with the wire and the capstans;
this process being characterized by the following points:
  • a) the capstans are heated or cooled by means of the gas also arranged between the capstans and at least one part, this gas being in contact with the capstans and the part, this part which conducts heat, being located at the outside the capstans, by circulating a heat transfer fluid other than the gas in contact with the part, so that heat exchanges take place on the one hand between the gas and the part and on the other hand between the part and the fluid;
  • b) the thickness of the gas layer, between the capstans and the part, is adjusted according to the heat treatment to be carried out.

L'invention concerne également un dispositif permettant de traiter thermiquement au moins un fil métallique à l'aide de cabestans, le dispositif comportant au moins deux cabestans conduisant la chaleur et comprenant des gorges, le dispositif comportant en outre des moyens permettant de faire défiler le fil dans les gorges des cabestans, le fil étant mouflé croisé dans ces gorges, la largeur des gorges étant légèrement supérieure à celle du fil, et un gaz, dans les gorges, au contact du fil et des cabestans ;
le dispositif étant caractérisé par les points suivants :

  • a) il comporte des moyens permettant de chauffer ou de refroidir les cabestans, ces moyens comprenant :
    • au moins une pièce conduisant la chaleur et située à l'extérieur des cabestans ;
    • des moyens permettant de faire circuler un fluide caloporteur autre que le gaz au contact de la pièce ;
    • le gaz disposé également entre les cabestans et la pièce, au contact des cabestans et de la pièce ;
    ces moyens étant agencés afin que des échanges thermiques s'effectuent d'une part entre le gaz et la pièce et d'autre part entre la pièce et le fluide ;
  • b) il comporte des moyens permettant de régler l'épaisseur de la couche de gaz entre les cabestans et la pièce, en fonction du traitement thermique à effectuer.
The invention also relates to a device making it possible to heat treat at least one metal wire using capstans, the device comprising at least two capstans conducting heat and comprising grooves, the device further comprising means making it possible to scroll the wire in the grooves of the capstans, the wire being crossed crossed in these grooves, the width of the grooves being slightly greater than that of the wire, and a gas, in the grooves, in contact with the wire and the capstans;
the device being characterized by the following points:
  • a) it includes means making it possible to heat or cool the capstans, these means comprising:
    • at least one heat conducting part located outside the capstans;
    • means for circulating a heat transfer fluid other than gas in contact with the part;
    • the gas also arranged between the capstans and the part, in contact with the capstans and the part;
    these means being arranged so that heat exchanges take place on the one hand between the gas and the part and on the other hand between the part and the fluid;
  • b) it comprises means making it possible to adjust the thickness of the layer of gas between the capstans and the part, as a function of the heat treatment to be carried out.

L'invention concerne également les installations de traitement thermique de fils métalliques comprenant au moins un dispositif conforme à l'invention.The invention also relates to installations for the thermal treatment of metal wires comprising at least one device according to the invention.

L'invention sera aisément comprise à l'aide des exemples non limitatifs qui suivent et des figures toutes schématiques relatives à ces exemples.The invention will be easily understood with the aid of the following non-limiting examples and all schematic figures relating to these examples.

Sur le dessin :

  • La figure 1 représente en coupe un dispositif conforme à l'invention comportant deux cabestans comportant des gorges, cette coupe étant schématisée par les segments de ligne droite I-I à la figure 2 ;
  • La figure 2 représente selon une autre coupe le dispositif conforme à l'invention représenté à la figure 1, la coupe de la figure 2 étant schématisée par les segments de ligne droite II-II à la figure 1 ;
  • La figure 3 est une vue de face des deux cabestans du dispositif conforme à l'invention représenté aux figures 1 et 2, avec le fil mouflé sur ces cabestans les autres parties du dispositif étant supposées enlevées ;
  • La figure 4 est une vue latérale des deux cabestans du dispositif conforme à l'invention représenté aux figures 1 et 2, avec le fil mouflé sur ces cabestans, les autres parties du dispositif étant supposées enlevées ;
  • La figure 5 est une coupe d'une portion d'un des cabestans représentés aux figures 3 et 4, cette coupe étant schématisée par les segments de lignes droites V-V à la figure 3 ;
  • La figure 6 représente plus en détail en coupe une des gorges du cabestan représenté à la figure 5, la coupe étant effectuée dans les mêmes conditions qu'à la figure 5 ;
  • La figure 7 représente une installation complète comportant six dispositifs conformes à l'invention, cette installation permettant d'effectuer un traitement de perlitisation ;
  • La figure 8 représente l'évolution, en fonction du temps, de la température du fil et des cabestans dans l'installation représentée à la figure 7 ;
  • La figure 9 représente l'évolution de la transformation de l'austénite en perlite au cours du temps lors du traitement du fil dans l'installation représentée à la figure 7 ;
  • La figure 10 représente en coupe une portion de la structure perlitique du fil traité dans l'installation représentée à la figure 7.
On the drawing :
  • Figure 1 shows in section a device according to the invention comprising two capstans comprising grooves, this section being shown schematically by the straight line segments II in Figure 2;
  • Figure 2 shows in another section the device according to the invention shown in Figure 1, the section of Figure 2 being shown schematically by the straight line segments II-II in Figure 1;
  • Figure 3 is a front view of the two capstans of the device according to the invention shown in Figures 1 and 2, with the wire on these capstans the other parts of the device being assumed removed;
  • Figure 4 is a side view of the two capstans of the device according to the invention shown in Figures 1 and 2, with the wire on these capstans, the other parts of the device being assumed removed;
  • Figure 5 is a section through a portion of one of the capstans shown in Figures 3 and 4, this section being shown schematically by the straight line segments VV in Figure 3;
  • Figure 6 shows in more detail in section one of the capstan grooves shown in Figure 5, the cut being carried out under the same conditions as in Figure 5;
  • FIG. 7 represents a complete installation comprising six devices in accordance with the invention, this installation making it possible to perform a pearlitization treatment;
  • Figure 8 shows the evolution, as a function of time, of the temperature of the wire and the capstans in the installation shown in Figure 7;
  • FIG. 9 represents the evolution of the transformation of austenite into perlite over time during the treatment of wire in the installation shown in Figure 7;
  • FIG. 10 shows in section a portion of the pearlitic structure of the wire treated in the installation shown in FIG. 7.

Les figures 1 et 2 représentent un dispositif 1 conforme à l'invention mettant en oeuvre le procédé conforme à l'invention. Ce dispositif 1 comporte deux cabestans 2,3 sur lesquels s'enroule le fil 4 à traiter. Les cabestans 2,3 conducteurs de la chaleur sont réalisés par exemple avec des matières métalliques. L'axe de rotation du cabestan 2 est référencé xx' et l'axe du cabestan 3 est référencé yy'. Les axes xx' et yy' sont parallèles entre eux et situés par exemple dans un même plan vertical. La figure 1 est une coupe du dispositif 1 suivant le plan vertical passant par les axes xx' et yy' ; la figure 2 est une coupe du dispositif 1 suivant un plan vertical perpendiculaire aux axes xx' et yy' ; la figure 3 est une vue de face des cabestans 2 et 3, avec le fil 4 mouflé sur ces cabestans et la figure 4 est une vue latérale de ces cabestans 2 et 3 avec le fil 4 mouflé sur ces cabestans les autres parties du dispositif 1 étant supposées enlevées sur ces figures 3 et 4. La coupe de la figure 1 est schématisée par les segments de ligne droite I-I à la figure 2, et la coupe de la figure 2 est schématisé par les segments de ligne droite II-II à la figure 1. L'axe xx' est représenté par la lettre x aux figures 2 et 3 et l'axe yy' est représenté par la lettre y aux figures 2 et 3. Le fil 4 arrive, dans la direction de la flèche Fa, au point 5 du cabestan inférieur 2 (figure 3). Le cabestan 2 est actionné en rotation autour de l'axe xx' par un moteur non représenté sur le dessin dans un but de simplification, la rotation du cabestan 2 étant schématisée par la flèche F₂. Le fil 4 est entraîné par le cabestan 2 jusqu'au point 6 où il quitte le cabestan 2 et se dirige dans le sens de la flèche F₂₋₃ vers le cabestan supérieur 3 non motorisé. Il prend contact au point 7 avec le cabestan 3 qui le soutient jusqu'au point 8, la rotation du cabestan 3 autour de l'axe yy' étant schématisée par la flèche F₃.Figures 1 and 2 show a device 1 according to the invention implementing the method according to the invention. This device 1 comprises two capstans 2,3 on which the wire 4 to be treated is wound. The capstans 2,3 heat conductors are made for example with metallic materials. The axis of rotation of the capstan 2 is referenced xx 'and the axis of the capstan 3 is referenced yy'. The axes xx 'and yy' are parallel to each other and located for example in the same vertical plane. Figure 1 is a section of the device 1 along the vertical plane passing through the axes xx 'and yy'; Figure 2 is a section of the device 1 along a vertical plane perpendicular to the axes xx 'and yy'; Figure 3 is a front view of the capstans 2 and 3, with the wire 4 mouflé on these capstans and Figure 4 is a side view of these capstans 2 and 3 with the wire 4 mouflé on these capstans the other parts of the device 1 being assumed removed in these Figures 3 and 4. The section of Figure 1 is shown schematically by the straight line segments II in Figure 2, and the section of Figure 2 is shown schematically by the straight line segments II-II in the FIG. 1. The axis xx 'is represented by the letter x in FIGS. 2 and 3 and the axis yy' is represented by the letter y in FIGS. 2 and 3. The wire 4 arrives, in the direction of the arrow Fa, at point 5 of the lower capstan 2 (Figure 3). The capstan 2 is actuated in rotation about the axis xx 'by a motor not shown in the drawing for the purpose of simplification, the rotation of the capstan 2 being shown diagrammatically by the arrow F₂. The wire 4 is driven by the capstan 2 to point 6 where it leaves the capstan 2 and goes in the direction of the arrow F₂₋₃ towards the upper capstan 3 non-motorized. It makes contact at point 7 with the capstan 3 which supports it up to point 8, the rotation of the capstan 3 around the axis yy 'being shown diagrammatically by the arrow F₃.

Le fil 4 quitte alors le cabestan 3 et se déplace dans le sens de la flèche F₃₋₂ jusqu'au cabestan 2 qu'il contacte au point 9. Le cabestan 2 entraîne alors le fil 4 une nouvelle fois dans sa rotation en direction du cabestan 3. Le mouflage du fil 4 sur les cabestans 2 et 3 est croisé, c'est-à-dire que la rotation F₃ du cabestan 3, entraîné par le fil 4, est de sens opposé à la rotation F₂ du cabestan 2, les directions F₂₋₃ et F₃₋₂ se croisant, sans qu'il y ait de contact entre les portions successives du fil 4 entre les cabestans 2 et 3. Ce trajet est répété plusieurs fois, le fil 4 effectuant ainsi plusieurs parcours en forme de huit sur les deux cabestans 2 et 3. Le fil 4 quitte enfin la paire de cabestans 2,3 au point 10 du cabestan inférieur 2, dans le sens de la flèche Fs (figure 3).The wire 4 then leaves the capstan 3 and moves in the direction of the arrow F₃₋₂ to the capstan 2 which it contacts at point 9. The capstan 2 then drives the wire 4 once again in its rotation towards the capstan 3. The hauling of the wire 4 on the capstans 2 and 3 is crossed, that is to say that the rotation F₃ of the capstan 3, driven by the wire 4, is in the opposite direction to the rotation F₂ of the capstan 2, the directions F₂₋₃ and F₃₋₂ crossing, without there being any contact between the successive portions of the wire 4 between the capstans 2 and 3. This path is repeated several times, the wire 4 thus carrying out several courses in shape of eight on the two capstans 2 and 3. The wire 4 finally leaves the pair of capstans 2,3 at point 10 of the lower capstan 2, in the direction of the arrow Fs (FIG. 3).

Le contact du fil 4 avec les cabestans 2 et 3 s'effectue dans des gorges 11 pratiquées sur ces cabestans.The contact of the wire 4 with the capstans 2 and 3 takes place in grooves 11 made on these capstans.

La figure 5 est une coupe d'une portion du cabestan 2, selon un plan passant par l'axe xx' de ce cabestan, cette coupe étant schématisée par les segments de lignes droites V-V à la figure 3.FIG. 5 is a section through a portion of the capstan 2, along a plane passing through the axis xx ′ of this capstan, this section being shown diagrammatically by the segments of straight lines V-V in FIG. 3.

Cette coupe présente des gorges 11 dont une est représentée agrandie à la figure 6, avec le fil 4 disposé dans cette gorge, la coupe de la figure 6 étant effectuée selon le même plan que la figure 5. Le cabestan 2 comporte par exemple sept gorges 11, chacune de ces gorges ayant pour axe l'axe xx' du cabestan 2. Dans le plan de la figure 6, la largeur J de la gorge 11 est légèrement supérieure au diamètre Df du fil 4, la gorge 11 ayant un fond 110 dont la forme est un demi-cercle de diamètre J à la figure 6. Toutes les gorges 11 des cabestans 2 et 3 ont la même forme et la même largeur J.This section has grooves 11, one of which is shown enlarged in Figure 6, with the wire 4 disposed in this groove, the section of Figure 6 being made along the same plane as Figure 5. The capstan 2 comprises for example seven grooves 11, each of these grooves having as axis the axis xx 'of the capstan 2. In the plane of FIG. 6, the width J of the groove 11 is slightly greater than the diameter D f of the wire 4, the groove 11 having a bottom 110 whose shape is a semicircle of diameter J at the Figure 6. All the grooves 11 of the capstans 2 and 3 have the same shape and the same width J.

Le jeu radial (J-Df)/2 et l'écartement p entre les gorges 11 (pas des gorges) doivent être suffisamment grands pour que le fil 4 puisse aller de la gorge 11 d'un cabestan à la gorge 11 correspondante de l'autre cabestan, sans qu'il y ait de frottement du fil 4 sur lui-même aux endroits où les portions du fil 4 se croisent, entre les cabestans 2,3 (fig. 5 et 6), ces valeurs pouvant être choisies par l'homme de l'art en fonction de l'application.The radial clearance (JD f ) / 2 and the spacing p between the grooves 11 (not the grooves) must be large enough so that the wire 4 can go from the groove 11 of a capstan to the corresponding groove 11 of the another capstan, without there being friction of the wire 4 on itself at the places where the portions of the wire 4 cross, between the capstans 2,3 (fig. 5 and 6), these values being able to be chosen by l skilled in the art depending on the application.

De préférence les gorges 11 du cabestan 3 non entraîné sont localisées sur des anneaux 12 d'axe yy'. Ces anneaux qui conduisent la chaleur et sont réalisés par exemple en matière métallique sont désolidarisés mécaniquement du corps 13 du cabestan 3 (figure 1). Le corps 13 tourne librement autour de l'axe yy' et les anneaux 12 peuvent tourner librement autour de l'axe yy', indépendamment du corps 13, ces anneaux 12 glissant sur la surface cylindrique 14 du corps 13. D'autre part les anneaux 12 peuvent tourner librement les uns par rapport aux autres. Cette disposition permet d'améliorer le contact entre le fil 4 et le cabestan 3 et d'améliorer la tension du fil 4 entre les cabestans 2, 3.Preferably the grooves 11 of the capstan 3 not driven are located on rings 12 of axis yy '. These rings which conduct heat and are made for example of metallic material are mechanically separated from the body 13 of the capstan 3 (Figure 1). The body 13 rotates freely around the axis yy 'and the rings 12 can rotate freely around the axis yy', independently of the body 13, these rings 12 sliding on the cylindrical surface 14 of the body 13. On the other hand the 12 rings can rotate freely with respect to each other. This arrangement improves the contact between the wire 4 and the capstan 3 and improves the tension of the wire 4 between the capstans 2, 3.

Le chauffage ou le refroidissement des cabestans 2,3 est effectué par une pièce conduisant la chaleur, par exemple un plateau 15 métallique à deux parois 16, 17 entre lesquelles s'écoule un fluide caloporteur 18, par exemple un liquide, notamment de l'eau, la paroi 16 étant disposée du côté des cabestans 2, 3. Les moyens permettant la circulation du fluide 18 entre les parois 16, 17 sont des moyens connus, comportant par exemple une pompe, et ils ne sont pas représentés sur le dessin dans un but de simplification. Le fluide 18 arrive par la tubulure 19, il circule entre les parois 16, 17 puis sort du plateau 15 par la tubulure 20, l'écoulement du fluide 18 étant schématisé par les flèches F₁₈. Les cabestans 2,3 sont montés sur des arbres 21 tournant dans des paliers 22, 23. Les arbres 21 traversent les parois 16, 17 et ils sont séparés de façon étanche du fluide 18 (figure 1). Les paliers 22 sont entourés chacun par un manchon 24 dans lequel circule un fluide 25 de refroidissement, la circulation de ce fluide 25 n'étant pas représentée dans un but de simplification. Le fluide 25 peut être le fluide 18, qui est alors lui-même un fluide de refroidissement, le manchon 24 communiquant alors avec l'intérieur du plateau 15 où circule le fluide 18.The heating or cooling of the capstans 2,3 is carried out by a heat conducting part, for example a metal plate 15 with two walls 16, 17 between which a heat transfer fluid 18, for example a liquid, in particular liquid, flows. water, the wall 16 being disposed on the side of the capstans 2, 3. The means allowing the circulation of the fluid 18 between the walls 16, 17 are known means, comprising for example a pump, and they are not shown in the drawing in a goal of simplification. The fluid 18 arrives by the tubing 19, it circulates between the walls 16, 17 then leaves the plate 15 by the tubing 20, the flow of the fluid 18 being shown diagrammatically by the arrows F₁₈. The capstans 2,3 are mounted on shafts 21 rotating in bearings 22, 23. The shafts 21 pass through the walls 16, 17 and they are sealed from the fluid 18 (FIG. 1). The bearings 22 are each surrounded by a sleeve 24 in which circulates a cooling fluid 25, the circulation of this fluid 25 not being shown for the purpose of simplification. The fluid 25 can be the fluid 18, which is then itself a cooling fluid, the sleeve 24 then communicating with the interior of the plate 15 where the fluid 18 circulates.

Les cabestans 2,3 sont placés dans une enceinte 26 contenant un gaz 27 de préférence non oxydant, par exemple de l'hydrogène ou un mélange d'hydrogène et d'azote. Les échanges thermiques entre les cabestans 2,3 et le fluide caloporteur 18 s'effectuent par l'intermédiaire du gaz 27 formant une couche 28, d'épaisseur H, située entre la face 160, sensiblement plane, de la paroi 16 d'une part, et chaque face 130, sensiblement plane, des cabestans 2, 3 d'autre part. Les faces 130 sont disposées sensiblement dans un même plan qui est perpendiculaire aux axes xx', yy' et sensiblement parallèle à la face 160 qui limite donc en partie l'enceinte 26, le gaz 27 étant au contact des cabestans 2,3 et de la face 160. Lorsque le traitement thermique du fil 4 est un réchauffement, le fluide 18, s'il est utilisé, est un fluide chauffant, la chaleur allant du fluide 18 vers le gaz 27, puis du gaz 27 vers les cabestans 2,3, enfin de ces cabestans vers le fil 4. Lorsque le traitement du fil 4 est un refroidissement, le fluide 18 est un fluide réfrigérant, et la chaleur s'écoule en sens inverse, depuis le fil 4 vers le fluide 18. Le gaz 27 en contact direct avec le plateau 15 et les cabestans 2,3 permet cet échange thermique, le plateau 15 étant réalisé avec une matière conduisant la chaleur, par exemple une matière métallique. Les éléments filetés 29 permettent de faire varier la distance H, en déplaçant les cabestans 2,3 le long de leurs axes respectifs xx' et yy'. Dans ce but, les éléments filetés 29 sont vissés dans les filetages femelles 30, dans des parties fixes 31 du dispositif 1. La modification de l'épaisseur H de la couche 28 du gaz 27 de couplage thermique est obtenu en agissant sur le levier 32 qui entraîne en rotation les éléments filetés 29, ce qui provoque un déplacement axial de ces éléments filetés 29, ce déplacement axial étant transmis aux arbres 21 par l'intermédiaire des épaulements 33 usinés sur les arbres 21. Le levier 32 permet d'actionner simultanément les deux arbres 21 des cabestans 2,3 par des moyens connus 34, schématisés par des lignes pointillées à la figure 1, ces moyens étant par exemple une courroie crantée ou une chaîne. Les échanges thermiques s'opèrent entre le fil 4 et les cabestans 2 ou 3 d'une part par contact direct le long de la ligne 35 de contact entre le fil et les cabestans, sur le fond 110 de la gorge 11 et d'autre part en passant au travers du gaz 27 qui se trouve dans les gorges 11 au contact du fil 4 et des cabestans 2,3, ce flux thermique étant schématisé par les flèches F₂₇ (figure 6) dans le cas d'un refroidissement du fil 4. De même, il serait possible d'utiliser plusieurs pièces 15 dans le dispositif 1, mais il est préférable de n'en utiliser qu'une, dans un but de simplification.The capstans 2,3 are placed in an enclosure 26 containing a gas 27 preferably non-oxidizing, for example hydrogen or a mixture of hydrogen and nitrogen. The heat exchanges between the capstans 2,3 and the heat transfer fluid 18 are effected by means of the gas 27 forming a layer 28, of thickness H, situated between the substantially flat face 160 of the wall 16 of a part, and each face 130, substantially planar, of the capstans 2, 3 on the other hand. The faces 130 are arranged substantially in the same plane which is perpendicular to the axes xx ', yy' and substantially parallel to the face 160 which therefore partly limits the enclosure 26, the gas 27 being in contact with the capstans 2,3 and the face 160. When the heat treatment of the wire 4 is a heating, the fluid 18, if it is used, is a heating fluid, the heat going from the fluid 18 to the gas 27, then from the gas 27 to the capstans 2, 3, finally from these capstans to the wire 4. When the treatment of the wire 4 is cooling, the fluid 18 is a cooling fluid, and the heat flows in the opposite direction, from the wire 4 to the fluid 18. The gas 27 in direct contact with the plate 15 and the capstans 2,3 allows this heat exchange, the plate 15 being produced with a material conducting the heat, for example a metallic material. The threaded elements 29 make it possible to vary the distance H, by moving the capstans 2,3 along their respective axes xx 'and yy'. For this purpose, the threaded elements 29 are screwed into the female threads 30, in fixed parts 31 of the device 1. The modification of the thickness H of the layer 28 of the gas 27 of thermal coupling is obtained by acting on the lever 32 which rotates the threaded elements 29, which causes an axial displacement of these threaded elements 29, this axial displacement being transmitted to the shafts 21 via the shoulders 33 machined on the shafts 21. The lever 32 makes it possible to actuate simultaneously the two shafts 21 of the capstans 2,3 by known means 34, shown diagrammatically by dotted lines in FIG. 1, these means being for example a toothed belt or a chain. The heat exchanges take place between the wire 4 and the capstans 2 or 3 on the one hand by direct contact along the line 35 of contact between the wire and the capstans, on the bottom 110 of the groove 11 and on the other leaves by passing through the gas 27 which is in the grooves 11 in contact with the wire 4 and the capstans 2,3, this heat flow being shown diagrammatically by the arrows F₂₇ (FIG. 6) in the case of a cooling of the wire 4 Similarly, it would be possible to use several parts 15 in the device 1, but it is preferable to use only one, for the purpose of simplification.

La limitation du jeu radial (J-Df)/2 permet de faciliter les échanges thermiques entre le fil 4 et les cabestans 2,3.The limitation of the radial clearance (JD f ) / 2 makes it possible to facilitate the heat exchanges between the wire 4 and the capstans 2,3.

Lorsque le traitement thermique consiste à refroidir rapidement un fil de diamètre important, le gaz 27 doit être bon conducteur de la chaleur car sans cela, l'épaisseur H de la couche 28 de gaz 27, entre le plateau 15 et les cabestans 2,3 pourrait être du même ordre que les dilations des matériaux constituant l'installation. On a de préférence 1 mm ≦ H ≦ 200 mm.When the heat treatment consists in rapidly cooling a wire of large diameter, the gas 27 must be a good conductor heat because without it, the thickness H of the layer 28 of gas 27, between the plate 15 and the capstans 2,3 could be of the same order as the dilations of the materials constituting the installation. We preferably have 1 mm ≦ H ≦ 200 mm.

De préférence, le gaz 27 dans l'enceinte 26, et donc dans la couche 28, ne subit pratiquement pas d'autres mouvements que ceux qui sont dus à la rotation des cabestans 2,3.Preferably, the gas 27 in the enclosure 26, and therefore in the layer 28, undergoes practically no other movements than those which are due to the rotation of the capstans 2,3.

Les cabestans 2,3 sont placés dans une enceinte 36 isolée extérieurement par un élément 37. Lorsque le dispositif 1 est destiné à effectuer un traitement thermique sur un fil 4 déjà chaud, l'enceinte 36 est par exemple équipée d'éléments électriques chauffants 38 répartis régulièrement sur son périmètre. Les éléments chauffants 38, par exemple des résistances, permettent alors le chauffage des cabestans 2,3 au démarrage du dispositif 1 et ainsi d'obtenir des mises en régime très rapides. Les arbres 21 sont protégés thermiquement par des boucliers thermiques 39. Ces éléments 38 peuvent aussi servir par exemple lorsque le traitement thermique est un traitement de chauffage, le fluide 18 pouvant alors ne pas être utilisé.The capstans 2,3 are placed in an enclosure 36 isolated externally by an element 37. When the device 1 is intended to carry out a heat treatment on an already hot wire 4, the enclosure 36 is for example equipped with electric heating elements 38 regularly distributed around its perimeter. The heating elements 38, for example resistors, then make it possible to heat the capstans 2,3 when the device 1 is started and thus to obtain very rapid revivals. The shafts 21 are thermally protected by heat shields 39. These elements 38 can also be used for example when the heat treatment is a heating treatment, the fluid 18 then being able not to be used.

Lorsque le traitement thermique comporte des régimes éloignés de l'isothermicité, il est préférable d'adapter les diamètres d'enroulement sur les gorges des cabestans aux variations de longueur du fil 4 avec sa température, c'est-à-dire que le diamètre d'enroulement De du fil à l'entrée d'un cabestan 2,3 est différent du diamètre d'enroulement Ds du fil à la sortie de ce cabestan, De et Ds correspondant donc à deux gorges extrêmes de ce cabestan. A titre d'exemple, la figure 5 montre une disposition correspondant à un refroidissement du fil 4 lors de son passage sur le cabestan 2, le diamètre De étant supérieur au diamètre Ds. Dans le cas d'un échauffement, la disposition serait inverse avec dans ce cas De < Ds. Pour faciliter les échanges thermiques, la distance E entre les axes xx' et yy' des cabestans 2,3 est la plus faible possible en tenant compte de l'encombrement de ces cabestans, et en évitant les contacts entre les diverses portions du fil 4 entre ces cabestans 2,3.When the heat treatment involves regimes far from isothermicity, it is preferable to adapt the winding diameters on the capstan grooves to variations in length of the wire 4 with its temperature, that is to say that the diameter winding De of the wire at the inlet of a capstan 2,3 is different from the winding diameter Ds of the wire at the outlet of this capstan, D e and D s therefore corresponding to two extreme grooves of this capstan. By way of example, FIG. 5 shows an arrangement corresponding to cooling of the wire 4 during its passage over the capstan 2, the diameter D e being greater than the diameter D s . In the case of a heating, the arrangement would be opposite with in this case D e <D s . To facilitate heat exchanges, the distance E between the axes xx 'and yy' of the capstans 2,3 is as small as possible, taking into account the size of these capstans, and avoiding contact between the various portions of the wire 4 between these capstans 2.3.

Les cabestans 2,3 et le plateau 15 conducteurs de la chaleur sont réalisés par exemple en bronze en acier ou en fonte.The capstans 2,3 and the plate 15 conductors of the heat are made for example of bronze steel or cast iron.

La figure 7 représente une installation complète 100 conforme à l'invention permettant de traiter thermiquement un fil 4 en acier pour lui faire subir un traitement d'austénitisation suivi d'un traitement de perlitisation.FIG. 7 represents a complete installation 100 in accordance with the invention making it possible to heat treat a steel wire 4 to subject it to an austenitization treatment followed by a pearlitization treatment.

Cette installation complète 100 comporte un dispositif 50 et six paires de cabestans référencés P₁ à P₆ identiques au dispositif 1 conforme à l'invention précédemment décrit. Les dispositifs P₁ à P₆ conformes à l'invention permettent de refroidir le fil 4 ou de le maintenir à une température pratiquement constante, le fluide caloporteur 18 étant par exemple de l'eau. Pour la simplicité du dessin seuls les cabestans des paires P₁ à P₆ et le fil 4 à traiter sont représentés sur cette figure 7.This complete installation 100 comprises a device 50 and six pairs of capstans referenced P₁ to P₆ identical to the device 1 according to the invention described above. The devices P₁ to P₆ in accordance with the invention make it possible to cool the wire 4 or to maintain it at a practically constant temperature, the heat transfer fluid 18 being for example water. For the simplicity of the drawing, only the capstans of the pairs P₁ to P₆ and the wire 4 to be treated are shown in this figure 7.

La figure 8 représente l'évolution de la température du fil 4 et des cabestans 2,3 lors d'un traitement thermique de perlitisation, le fil 4 étant en acier, la température T correspondant à l'axe des ordonnées et le temps "t" à l'axe des abscisses. Le fil 4 pénètre dans le dispositif 50 où il subit un traitement d'austénitisation. Ce dispositif 50 comporte deux cabestans 51, 52 sur lesquels est mouflé le fil 4, et on fait passer un flux magnétique alternatif dans les boucles de fil 4 ainsi formées, ce flux étant produit par l'inducteur 53. On produit ainsi un courant électrique induit dans le fil 4, ce qui permet de chauffer ce fil à une température supérieure à la température de transformation AC3 de façon à obtenir une structure d'austénite homogène, la température Tf1 atteinte par le fil 4 dans le dispositif 50 étant par exemple de l'ordre de 900 à 1000°C.FIG. 8 represents the evolution of the temperature of the wire 4 and the capstans 2,3 during a pearlitization heat treatment, the wire 4 being made of steel, the temperature T corresponding to the ordinate axis and the time "t "on the x-axis. The wire 4 enters the device 50 where it undergoes an austenitization treatment. This device 50 comprises two capstans 51, 52 on which the wire 4 is mouflaged, and an alternating magnetic flux is passed through the loops of wire 4 thus formed, this flux being produced by the inductor 53. An electric current is thus produced induced in wire 4, which makes it possible to heat this wire to a temperature higher than the transformation temperature AC3 so as to obtain a homogeneous austenite structure, the temperature T f1 reached by the wire 4 in the device 50 being for example of the order of 900 to 1000 ° C.

Le fil 4 qui sort de l'installation 50 arrive ensuite sur le cabestan 2 de la paire de cabestan P₁. Les cabestans 2,3 de la paire P₁ sont maintenus à une température Tc₁ de l'ordre de 450 à 650°C. Sur la figure 8, l'origine 0 des temps correspond à l'arrivée du fil 4 sur la paire P1. Au bout d'un temps t₁ inférieur à 4 secondes le fil 4 atteint une température Tf₂ proche de celle des cabestans de la paire P₁. Ce refroidissement rapide permet donc la transformation d'austénite stable en austénite métastable. Le fil 4 passe ensuite successivement sur les quatre paires P₂ à P₅ dont le rôle est de maintenir le fil 4 à une température qui ne varie pas de plus de 10°C par excès ou par défaut de la température donnée Tf₂, la température Tf du fil 4 étant alors par exemple comprise dans l'intervalle Tf₂ - 8°C, Tf₂ + 8°C, et ceci pendant toute la durée de la transformation de l'austénite métastable en perlite et pendant environ 1 à 3 secondes suivant cette transformation. Le but de cette partie de l'installation est d'une part d'éviter la recalescence durant la période pendant laquelle se produit la pointe de puissance thermique due à la transformation d'austénite en perlite (qui conduirait à la formation de perlite grossière), d'autre part d'éviter un refroidissement prématuré avant que la transformation soit totale. Un refroidissement prématuré avant que la transformation soit totale risquerait de conduire à un produit contenant de la bainite donc à un fil fragile et d'une valeur d'usage médiocre en particulier en ce qui concerne l'endurance.The wire 4 which leaves the installation 50 then arrives on the capstan 2 of the pair of capstan P₁. The capstans 2,3 of the pair P₁ are maintained at a temperature Tc₁ of the order of 450 to 650 ° C. In FIG. 8, the origin 0 of the times corresponds to the arrival of the wire 4 on the pair P1. After a time t₁ of less than 4 seconds the wire 4 reaches a temperature Tf₂ close to that of the capstans of the pair P₁. This rapid cooling therefore allows the transformation of stable austenite into metastable austenite. The wire 4 then passes successively over the four pairs P₂ to P₅ whose role is to maintain the wire 4 at a temperature which does not vary by more than 10 ° C by excess or by default of the given temperature Tf₂, the temperature Tf of wire 4 then being for example in the interval Tf₂ - 8 ° C, Tf₂ + 8 ° C, and this throughout the duration of the transformation of metastable austenite into perlite and for approximately 1 to 3 seconds following this transformation. The aim of this part of the installation is on the one hand to avoid recalescence during the period during which the peak of thermal power occurs due to the transformation of austenite into perlite (which would lead to the formation of coarse perlite) , on the other hand, to avoid premature cooling before the transformation is complete. Premature cooling before the transformation is complete could lead to a product containing bainite and therefore to a fragile wire and of a poor use value in particular as regards endurance.

Les temps de passage du fil 4 dans les paires P₂ à P₅ sont référencés respectivement t₂ à t₅, les températures des cabestans des paires P₂ à P₅ sont référencées respectivement Tc₂ à Tc₅. La somme t₂+t₃+t₄+t₅ est par exemple de l'ordre de 4 à 10 secondes. Pour les quatre paires P₂ à P₅, les diamètres d'enroulement du fil 4 sur chaque cabestan ne varient pas entre l'entrée et la sortie, c'est-à-dire que l'on a toujours De = Ds.The passage times of the wire 4 in the pairs P₂ to P₅ are respectively referenced t₂ to t₅, the temperatures of the capstans of the pairs P₂ to P₅ are respectively referenced Tc₂ in Tc₅. The sum t₂ + t₃ + t₄ + t₅ is for example of the order of 4 to 10 seconds. For the four pairs P₂ to P₅, the winding diameters of the wire 4 on each capstan do not vary between the inlet and the outlet, that is to say that we always have De = Ds.

La figure 9 montre l'évolution de la transformation de l'austénite en perlite au cours du temps. Le temps "t" correspond à l'axe des abscisses, et le % de transformation en perlite à l'axe des ordonnées. La transformation pendant le temps t₂ est lente, la perlitisation ne commençant que vers la fin de ce temps t₂, la puissance à échanger est donc faible et la température Tc₂ de la deuxième paire P₂ est légèrement inférieure à la température visée pour la transformation (Tf₂). La transformation pendant le temps t₃ est très rapide, la puissance à échanger est donc plus importante, et la température Tc₃ de la troisième paire P₃ est sensiblement plus basse que la température Tc₂ de la deuxième paire P₂. La transformation pendant le temps t₄ se produit à une vitesse sensiblement identique à celle du temps t₂, la température Tc₄ de la quatrième paire P₄ est donc très proche de Tc₂. Durant le temps t₅ il n'y a pas de transformation métallurgique sensible du point de vue thermique, la température Tc₅ de la cinquième paire P₅ est donc sensiblement égale à Tf₂. Le but de ce maintien en température pendant le temps t₅ étant de s'assurer que la transformation en perlite est bien terminée avant le refroidissement correspondant au temps t₆.Figure 9 shows the evolution of the transformation of austenite into perlite over time. The time "t" corresponds to the abscissa axis, and the% of transformation into perlite to the ordinate axis. The transformation during the time t₂ is slow, the perlitization starting only towards the end of this time t₂, the power to be exchanged is therefore low and the temperature Tc₂ of the second pair P₂ is slightly lower than the target temperature for the transformation (Tf₂ ). The transformation during the time t₃ is very rapid, the power to be exchanged is therefore greater, and the temperature Tc₃ of the third pair P₃ is significantly lower than the temperature Tc₂ of the second pair P₂. The transformation during time t₄ occurs at a speed substantially identical to that of time t₂, the temperature Tc₄ of the fourth pair P₄ is therefore very close to Tc₂. During the time t₅ there is no metallurgical transformation sensitive from the thermal point of view, the temperature Tc paire of the fifth pair P₅ is therefore substantially equal to Tf₂. The purpose of this temperature maintenance during the time t₅ being to ensure that the transformation into perlite is completed before the cooling corresponding to the time t₆.

De préférence, lors du refroidissement initial correspondant au temps t₁, on a les relations suivantes :

K₁ ≧ 0,3   (1)

Figure imgb0001


K₂ ≧ 0,85   (2)
Figure imgb0002

0,5 ≦ K₃ ≦ 1,5   (3)
Figure imgb0003

2x10⁻⁴ ≦ K₄≦ 6x10⁻⁴   (4)
Figure imgb0004

avec par définition :

K₁ = L₁/(JxD f - Df²)   (5)
Figure imgb0005

K₂ = De/E   (6)
Figure imgb0006

K₃ = 100 (De/Ds - 1)   (7)
Figure imgb0007

K₄ = (VxD f ²xH)/(L₂ xDe²)   (8)
Figure imgb0008

où L₁ est la conductibilité thermique du gaz qui se trouve dans les gorges 11 au contact du fil 4 et des cabestans 2,3, L₂ est la conductibilité thermique du gaz constituant la couche 28 de gaz 27, ces conductibilités L₁ et L₂ étant déterminées à 600°C et exprimées en watts.m⁻¹.°K⁻¹. Lorsqu'on utilise un même gaz 27 dans les gorges 11 et dans la couche 28, L₁ et L₂ sont identiques, et représentés par L ; Df est le diamètre du fil exprimé en millimètres ; J est la largeur des gorges 11 exprimée en millimètres ; E est l'entraxe des cabestans exprimé en millimètres ; De est le diamètre d'enroulement du fil 4 à l'entrée d'un cabestan quelconque 2,3 ; Ds est le diamètre d'enroulement du fil 4 à la sortie du même cabestan, De et Ds étant exprimés en millimètres ; V est la vitesse de défilement du fil exprimée en mètres par seconde ; H est l'épaisseur de la couche 28 du gaz 27, exprimée en millimètres.Preferably, during the initial cooling corresponding to time t₁, we have the following relationships:

K₁ ≧ 0.3 (1)
Figure imgb0001

K₂ ≧ 0.85 (2)
Figure imgb0002

0.5 ≦ K₃ ≦ 1.5 (3)
Figure imgb0003

2x10⁻⁴ ≦ K₄ ≦ 6x10⁻⁴ (4)
Figure imgb0004

with by definition:

K₁ = L₁ / (JxD f - Df²) (5)
Figure imgb0005

K₂ = From / E (6)
Figure imgb0006

K₃ = 100 (De / Ds - 1) (7)
Figure imgb0007

K₄ = (VxD f ²xH) / (L₂ xDe²) (8)
Figure imgb0008

where L₁ is the thermal conductivity of the gas which is in the grooves 11 in contact with the wire 4 and the capstans 2,3, L₂ is the thermal conductivity of the gas constituting the layer 28 of gas 27, these conductivities L₁ and L₂ being determined at 600 ° C and expressed in watts.m⁻¹. ° K⁻¹. When the same gas 27 is used in the grooves 11 and in the layer 28, L₁ and L₂ are identical, and represented by L; D f is the diameter of the wire expressed in millimeters; J is the width of the grooves 11 expressed in millimeters; E is the distance between the capstans expressed in millimeters; D e is the winding diameter of the wire 4 at the entry of any capstan 2,3; D s is the winding diameter of the wire 4 at the outlet of the same capstan, D e and D s being expressed in millimeters; V is the wire running speed expressed in meters per second; H is the thickness of the layer 28 of the gas 27, expressed in millimeters.

De préférence, dans au moins un des couples P₂ à P₅ correspondant à la phase pratiquement isotherme, les relations suivantes sont vérifiées :

K₂ ≧ 0,85   (9)

Figure imgb0009


K₃ = 0   (10)
Figure imgb0010

De façon avantageuse, les relations suivantes sont en outre vérifiées dans au moins un des couples P₂ à P₄

K₁ ≧ 0,3   (11)
Figure imgb0011

0,5x10⁻³ ≦ K₄ ≦ 9x10⁻³   (12).
Figure imgb0012
Preferably, in at least one of the pairs P₂ to P₅ corresponding to the practically isothermal phase, the following relationships are verified:

K₂ ≧ 0.85 (9)
Figure imgb0009

K₃ = 0 (10)
Figure imgb0010

Advantageously, the following relationships are furthermore verified in at least one of the pairs P₂ to P₄

K₁ ≧ 0.3 (11)
Figure imgb0011

0.5x10⁻³ ≦ K₄ ≦ 9x10⁻³ (12).
Figure imgb0012

Les relations (1) à (12) sont données dans le cas où le gaz 27 dans l'enceinte 26, et donc dans la couche 28, ne subit pratiquement pas d'autres mouvements que ceux qui sont dus à la rotation des cabestans 2,3.Relations (1) to (12) are given in the case where the gas 27 in the enclosure 26, and therefore in the layer 28, undergoes practically no other movements than those due to the rotation of the capstans 2 , 3.

L'isothermicité obtenue durant les phases t₂ à t₅ ne peut être qu'améliorée si le nombre d'éléments utilisés est supérieur à 4 mais cela conduit à un investissement plus élevé qui n'est pas nécessaire pour obtenir d'une part une isothermicité à ± 8°C, d'autre part la qualité du fil annoncée.The isothermicity obtained during phases t₂ to t₅ can only be improved if the number of elements used is greater than 4 but this leads to a higher investment which is not necessary to obtain on the one hand an isothermicity at ± 8 ° C, on the other hand the quality of the advertised wire.

La section de refroidissement final permet le refroidissement du fil d'une température Tf₂ de l'ordre de 450 à 650°C à une température Tf₃ de l'ordre de 100 à 200°C en un temps t₆ de l'ordre de 3 à 6 secondes, elle comporte une paire de cabestans mouflés croisés, le cabestan inférieur 2 est motorisé, le cabestan supérieur 3 ne l'est pas, le diamètre d'enroulement De sur la première gorge du cabestan inférieur est supérieur au diamètre Ds de la dernière gorge du cabestan inférieur, les cabestans sont maintenus à une température Tc₆ de l'ordre de 50 à 150°C.The final cooling section allows the cooling of the wire from a temperature Tf₂ of the order of 450 to 650 ° C to a temperature Tf₃ of the order of 100 to 200 ° C in a time t₆ of the order of 3 to 6 seconds, it includes a pair of crossed hauled capstans, the lower capstan 2 is motorized, the upper capstan 3 is not, the winding diameter D e on the first groove of the lower capstan is greater than the diameter Ds of the last groove of the lower capstan, the capstans are maintained at a temperature Tc₆ of the order of 50 to 150 ° C.

Les exemples qui suivent ont été réalisés avec l'installation 100 précédemment décrite, en utilisant pour chaque couple P₁ à P₆ un gaz 27 unique. On a donc L₁ = L₂ = L. Comme précédemment indiqué, pour chaque couple de cabestan, le gaz 27 dans l'enceinte 26, et donc dans la couche 28, ne subit pratiquement pas d'autres mouvements que ceux qui sont dus à la rotation des cabestans 2,3.The following examples were made with the installation 100 previously described, using for each pair P₁ to P₆ a single gas 27. We therefore have L₁ = L₂ = L. As previously indicated, for each pair of capstan, the gas 27 in the enclosure 26, and therefore in the layer 28, undergoes practically no other movements than those due to the rotation of the capstans 2.3.

La composition des aciers utilisés est donnée dans le tableau 1 TABLEAU 1 Type C Mn Si S P Al Ca Cr Ni 1 0,70 0,61 0,22 0,028 0,018 0,084 0,048 0,061 0,016 2 0,82 0,69 0,20 0,026 0,019 0,082 0,043 0,058 0,015
(Les chiffres correspondent à des % en poids)
Les cabestans 2,3 de l'ensemble des paires P₁ à P₆ ont été réalisés en acier réfractaire X 12 Cr Ni 25 21 (THERMAX 4845 de Thyssen) Cr = 25 % Ni = 20 %. Les caractéristiques de cet acier sont les suivantes :
Conductibilité thermique à 500°C : 19 w.m⁻¹.°K⁻¹
Dilatation thermique à 400°C : 17.10⁻⁶m.m⁻¹.°K⁻¹
Le taux de recouvrement Tr est le rapport entre la longueur de fil en contact avec les fonds de gorge et la longueur totale de fil située entre le premier point de contact 5 à l'arrivée sur l'élément de transfert thermique et le dernier point 10 à la sortie, c'est-à-dire entre les points 5 et 10 précédemment définis (figure 3).The composition of the steels used is given in Table 1 TABLE 1 Type VS Mn Yes S P Al It Cr Or 1 0.70 0.61 0.22 0.028 0.018 0.084 0.048 0.061 0.016 2 0.82 0.69 0.20 0.026 0.019 0.082 0.043 0.058 0.015
(Figures correspond to% by weight)
The capstans 2,3 of all the pairs P₁ to P₆ were made of refractory steel X 12 Cr Ni 25 21 (THERMAX 4845 from Thyssen) Cr = 25% Ni = 20%. The characteristics of this steel are as follows:
Thermal conductivity at 500 ° C: 19 wm⁻¹. ° K⁻¹
Thermal expansion at 400 ° C: 17.10⁻⁶m.m⁻¹. ° K⁻¹
The recovery rate T r is the ratio between the length of wire in contact with the groove bottoms and the total length of wire located between the first point of contact 5 on arrival on the heat transfer element and the last point 10 at the outlet, that is to say between points 5 and 10 previously defined (Figure 3).

Le rapport des sections est par définition :

Figure imgb0013

La déformation rationnelle est par définition

ε = Log(R)
Figure imgb0014

Log désignant le logarithme népérien.The report of the sections is by definition:
Figure imgb0013
Rational deformation is by definition

ε = Log (R)
Figure imgb0014

Log designating the natural logarithm.

Le temps d'incubation est le temps nécessaire pour que 1 % d'austénite métastable se transforme en perlite, ce temps étant compté à partir du commencement du refroidissement (arrivée du fil 4 sur la paire P₁).The incubation time is the time necessary for 1% of metastable austenite to transform into perlite, this time being counted from the beginning of the cooling (arrival of the wire 4 on the pair P₁).

Le temps de transformation est le temps nécessaire pour passer de 1 % à 99 % de perlite.The transformation time is the time necessary to go from 1% to 99% of perlite.

EXEMPLE 1EXAMPLE 1

Les conditions d'essais sont les suivantes :

  • Acier Type 1,
  • Temps d'incubation = 3 secondes environ,
  • Temps de transformation = 3 secondes environ,
  • Diamètre du fil : Df = 1,1 mm,
  • Vitesse V de défilement du fil : 15 m/s.
  • Gaz 27 :
    • . Pour les éléments de transfert thermique P₁ à P₄ : H₂ + N₂ avec 75 % de H₂ et 25 % de N₂ en volume (NH₃ craqué).
    • . Pour l'élément de maintien isotherme P₅ : N₂ pur.
    • . Pour l'élément de refroidissement final P₆ : H₂ pur.
The test conditions are as follows:
  • Steel Type 1,
  • Incubation time = approximately 3 seconds,
  • Processing time = approximately 3 seconds,
  • Wire diameter: D f = 1.1 mm,
  • Wire running speed V: 15 m / s.
  • Gas 27:
    • . For the heat transfer elements P₁ to P₄: H₂ + N₂ with 75% of H₂ and 25% of N₂ by volume (NH₃ cracked).
    • . For the isothermal holding element P₅: pure N₂.
    • . For the final cooling element P₆: pure H₂.

Un seul gaz est utilisé pour chaque élément de transfert thermique, dans un but de simplification technologique, c'est-à-dire que L₁ = L₂ = L mais en cas de nécessité il est possible d'utiliser des gaz différents pour le couplage thermique fil 4/cabestan 2 ou 3 et pour le couplage thermique cabestan 2 ou 3/plateau refroidisseur 15.A single gas is used for each heat transfer element, for the purpose of technological simplification, that is to say that L₁ = L₂ = L but if necessary it is possible to use different gases for thermal coupling wire 4 / capstan 2 or 3 and for thermal coupling capstan 2 or 3 / cooler plate 15.

Refroidissement primaire période t₁ Primary cooling period t ₁

Première paire de cabestans P₁
Diamètre des cabestans à l'entrée du fil : De = 1007 mm
Diamètre des cabestans à la sortie du fil : Ds = 1000 mm
Entre-axe des cabestans : E = 1050 mm
Taux de recouvrement des cabestans : Tr = 0,902
Pas des gorges : p = 10 mm
Largeur des gorges : J = 1,7 mm
Vitesse de rotation du cabestan 2 : 287 tours/minute
Temps de séjour : t₁ = 2,94 secondes
Nombre de spires : 7
Température initiale du fil : Tf₁ = 930°C
Température finale du fil : Tf₂ = 580°C
Les cabestans ont été maintenus à une température de : 520°C à
l'aide d'un débit d'eau à 25°C de : 2,4 m³/h
Epaisseur de la lame 28 de gaz 27 de couplage thermique : H = 7,8 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,424
K₂ = 0,959
K₃ = 0,7
K₄ = 4,99x10⁻⁴First pair of P₁ capstans
Diameter of the capstans at the entry of the wire: D e = 1007 mm
Diameter of the capstans at the wire outlet: D s = 1000 mm
Center distance of capstans: E = 1050 mm
Capstan recovery rate: T r = 0.902
Groove pitch: p = 10 mm
Groove width: J = 1.7 mm
Rotation speed of capstan 2: 287 rpm
Residence time: t₁ = 2.94 seconds
Number of turns: 7
Initial wire temperature: Tf₁ = 930 ° C
Final wire temperature: Tf₂ = 580 ° C
The capstans were kept at a temperature of: 520 ° C at
using a water flow at 25 ° C of: 2.4 m³ / h
Thickness of the gas coupling blade 28 of thermal coupling 27: H = 7.8 mm
Main parameters of the heat transfer element:
K₁ = 0.424
K₂ = 0.959
K₃ = 0.7
K₄ = 4.99x10⁻⁴

Maintien isotherme Périodes t₂, t₃, t₄, t₅ Isothermal maintenance Periods t ₂ , t ₃ , t ₄ , t ₅

Deuxième paire P₂ de cabestans période t₂
Diamètre des cabestans à l'entrée du fil : De = 1 000 mm
Diamètre des cabestans à la sortie du fil : Ds = 1 000 mm
Entre-axe des cabestans : E = 1 050 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 10 mm
Largeur des gorges : J = 1,7 mm
Vitesse de rotation du cabestan 2 : 289 tours/minute.
Temps de séjour : t₂ = 1,26 secondes
Nombre de spires : 3
La température du fil a été maintenue à 580 ± 5°C.
Les cabestans ont été maintenus à une température de : 545°C à
l'aide d'un débit d'eau à 25°C de : 0,15 m³/h.
Epaisseur de la lame de gaz de couplage thermique : H = 100 mm.
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,424
K₂ = 0,952
K₃= 0
K₄ = 6,48x10⁻³
Troisième paire P₃ de cabestans période t₃
Diamètre des cabestans à l'entrée du fil : De = 1000 mm
Diamètre des cabestans à la sortie du fil : Ds = 1000 mm
Entre-axe des cabestans : E = 1050 mm
Taux de recouvrement des cabestans Tr : 0,898
Pas des gorges : p = 10 mm
Largeur des gorges : J = 1,7 mm
Vitesse de rotation du cabestan 2 : 289 tours/minute.
Temps de séjour : t₃ = 1,26 secondes
Nombre de spires : 3
La température du fil a été maintenue à 580 ± 6°C.Second pair P₂ of capstans period t₂
Diameter of the capstans at the entry of the wire: D e = 1000 mm
Diameter of the capstans at the outlet of the wire: D s = 1000 mm
Center distance of capstans: E = 1050 mm
Capstan recovery rate: Tr = 0.898
Groove pitch: p = 10 mm
Groove width: J = 1.7 mm
Rotation speed of capstan 2: 289 rpm.
Residence time: t₂ = 1.26 seconds
Number of turns: 3
The wire temperature was maintained at 580 ± 5 ° C.
The capstans were kept at a temperature of: 545 ° C at
using a water flow at 25 ° C of: 0.15 m³ / h.
Thickness of the thermal coupling gas slide: H = 100 mm.
Main parameters of the heat transfer element:
K₁ = 0.424
K₂ = 0.952
K₃ = 0
K₄ = 6.48x10⁻³
Third pair P₃ of capstans period t₃
Diameter of the capstans at the wire entry: D e = 1000 mm
Diameter of the capstans at the wire outlet: D s = 1000 mm
Center distance of capstans: E = 1050 mm
Recovery rate of capstans T r : 0.898
Groove pitch: p = 10 mm
Groove width: J = 1.7 mm
Rotation speed of capstan 2: 289 rpm.
Residence time: t₃ = 1.26 seconds
Number of turns: 3
The wire temperature was maintained at 580 ± 6 ° C.

Les cabestans ont été maintenus à une température de : 417°C à l'aide d'un débit d'eau à 25°C de : 0,7 m³/h.The capstans were kept at a temperature of: 417 ° C using a water flow at 25 ° C of: 0.7 m³ / h.

Epaisseur de la lame de gaz de couplage thermique : H = 16,5 mm. Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,424
K₂ = 0,952
K₃ = 0
K₄ = 1,07x10⁻³
Quatrième paire P₄ de cabestans période t₄ : identique à la deuxième paire de cabestans.Thickness of the thermal coupling gas slide: H = 16.5 mm. Main parameters of the heat transfer element:
K₁ = 0.424
K₂ = 0.952
K₃ = 0
K₄ = 1.07x10⁻³
Fourth pair P₄ of capstans period t₄: identical to the second pair of capstans.

Cinquième paire P₅ de cabestans période t₅ Diamètre des cabestans à l'entrée du fil : De = 600 mm
Diamètre des cabestans à la sortie du fil : Ds = 600 mm
Entre-axe des cabestans : E = 630 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 10 mm
Largeur des gorges : J = 3 mm
Vitesse de rotation du cabestan 2 : 480 tours/minute.
Temps de séjour : t₅ = 1,26 secondes
Nombre de spires : 5
La température du fil a été maintenue à 580 ± 2°C.Fifth pair P₅ of capstans period t₅ Diameter of the capstans at the wire entry: D e = 600 mm
Diameter of the capstans at the outlet of the wire: D s = 600 mm
Center distance of capstans: E = 630 mm
Capstan recovery rate: T r = 0.898
Groove pitch: p = 10 mm
Groove width: J = 3 mm
Rotation speed of capstan 2: 480 rpm.
Residence time: t₅ = 1.26 seconds
Number of turns: 5
The wire temperature was maintained at 580 ± 2 ° C.

Les cabestans ont été maintenus à une température de : 585 ± 5°C grâce aux résistances électriques 38, la circulation d'eau a été coupée.The capstans were kept at a temperature of: 585 ± 5 ° C thanks to the electrical resistances 38, the water circulation was cut off.

L'épaisseur H de la lame de gaz de couplage thermique a été maintenue au maximum afin de limiter la consommation d'électricité soit : H = 50 mm.The thickness H of the thermal coupling gas blade was kept to the maximum in order to limit the consumption of electricity, ie: H = 50 mm.

Paramètres principaux de l'élément de transfert thermique :
K₁ = 2,392x10⁻²
K₂ = 0,952
K₃ = 0
K₄ = 5,04x10⁻²Main parameters of the heat transfer element:
K₁ = 2,392x10⁻²
K₂ = 0.952
K₃ = 0
K₄ = 5.04x10⁻²

Refroidissement final période t₆ Final cooling period t ₆

Sixième paire P₆ de cabestans
Diamètre des cabestans à l'entrée du fil : De = 1000 mm
Diamètre des cabestans à la sortie du fil : Ds = 993 mm
Entre-axe des cabestans : E = 1050 mm
Taux de recouvrement des cabestans : Tr = 0,894
Pas des gorges : p = 10 mm
Largeur des gorges : J = 1,7 mm
Vitesse de rotation du cabestan 2 : 287 tours/minute
Temps de séjour : t₆ = 4,19 secondes
Nombre de spires : 10
Température initiale du fil : Tf₂ = 580°C
Température finale du fil : Tf₃ = 193°C
Les cabestans ont été maintenus à une température de : 170°C à l'aide d'un débit d'eau à 25°C de : 2,13 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 1,5 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,424
K₂ = 0,952
K₃ = 0,7
K₄ = 9,08x10⁻⁵
Après traitement thermique, le fil 4 a une résistance à la rupture en traction de 1200 MPa (mégapascals).Sixth P₆ pair of capstans
Diameter of the capstans at the wire entry: D e = 1000 mm
Diameter of the capstans at the wire outlet: D s = 993 mm
Center distance of capstans: E = 1050 mm
Capstan recovery rate: T r = 0.894
Groove pitch: p = 10 mm
Groove width: J = 1.7 mm
Rotation speed of capstan 2: 287 rpm
Residence time: t₆ = 4.19 seconds
Number of turns: 10
Initial wire temperature: Tf₂ = 580 ° C
Final wire temperature: Tf₃ = 193 ° C
The capstans were kept at a temperature of: 170 ° C using a water flow at 25 ° C of: 2.13 m³ / h
Thickness of the thermal coupling gas slide: H = 1.5 mm
Main parameters of the heat transfer element:
K₁ = 0.424
K₂ = 0.952
K₃ = 0.7
K₄ = 9.08x10⁻⁵
After heat treatment, wire 4 has a tensile strength of 1200 MPa (megapascals).

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,17 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 3 000 MPa
R = 41,87
ε = 3,73This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.17 mm. Breaking strength in tension for this drawn wire is 3,000 MPa
R = 41.87
ε = 3.73

EXEMPLE 2EXAMPLE 2

Cet exemple est identique au précédent à l'exception du fait que l'on utilise un acier du type 2 au lieu d'un acier du type 1. Le temps d'incubation et le temps de transformation sont sensiblement les mêmes que dans l'exemple précédent.This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel. The incubation time and the transformation time are substantially the same as in previous example.

Après traitement thermique le fil a une résistance à la rupture en traction de 1350 MPa.After heat treatment, the wire has a tensile strength of 1350 MPa.

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,17 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 3500 MPa.
R = 41,87
ε = 3,73This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.17 mm. The tensile strength for this drawn wire is 3500 MPa.
R = 41.87
ε = 3.73

EXEMPLE 3EXAMPLE 3

Les conditions de cet essai sont les suivantes :

  • Acier Type 1
  • Temps d'incubation= 3 secondes environ
  • Temps de transformation = 3 secondes environ
  • Diamètre du fil : Df = 1,83 mm
  • Vitesse V de défilement du fil : 15 m/s
  • Gaz 27 :
    • . Pour les éléments de transfert thermique P₁ à P₄ : H₂ pur.
    • . Pour l'élément de maintien isotherme P₅ : N₂ pur.
    • . Pour l'élément de refroidissement final P₆ : H₂ pur.
The conditions of this test are as follows:
  • Steel Type 1
  • Incubation time = approximately 3 seconds
  • Processing time = about 3 seconds
  • Wire diameter: D f = 1.83 mm
  • Wire feed speed V: 15 m / s
  • Gas 27:
    • . For heat transfer elements P₁ to P₄: pure H₂.
    • . For the isothermal holding element P₅: pure N₂.
    • . For the final cooling element P₆: pure H₂.

Refroidissement primaire période t1Primary cooling period t1

Première paire P₁ de cabestans
Diamètre des cabestans à l'entrée du fil : De = 1 510 mm
Diamètre des cabestans à la sortie du fil : Ds = 1 500 mm
Entre-axe des cabestans : E = 1 575 mm
Taux de recouvrement des cabestans : Tr = 0,902
Pas des gorges : p = 11 mm
Largeur des gorges : J = 2,3 mm
Vitesse de rotation du cabestan 2 : 191 tours/minute
Temps de séjour : t₁ = 3,16 secondes
Nombre de spires : 5
Température initiale du fil : Tf₁ = 930°C
Température finale du fil : Tf₂ = 580°C
Les cabestans ont été maintenus à une température de : 540°C à
l'aide d'un débit d'eau à 25° C de : 7,16 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 7 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,488
K₂ = 0,959
K₃ = 0,67
K₄ = 3,67x10⁻⁴First P₁ pair of capstans
Diameter of the capstans at the wire entry: D e = 1 510 mm
Diameter of the capstans at the outlet of the wire: D s = 1,500 mm
Center distance of capstans: E = 1 575 mm
Capstan recovery rate: T r = 0.902
Groove pitch: p = 11 mm
Groove width: J = 2.3 mm
Rotation speed of capstan 2: 191 rpm
Residence time: t₁ = 3.16 seconds
Number of turns: 5
Initial wire temperature: Tf₁ = 930 ° C
Final wire temperature: Tf₂ = 580 ° C
The capstans were kept at a temperature of: 540 ° C at
using a water flow at 25 ° C of: 7.16 m³ / h
Thickness of the thermal coupling gas slide: H = 7 mm
Main parameters of the heat transfer element:
K₁ = 0.488
K₂ = 0.959
K₃ = 0.67
K₄ = 3.67x10⁻⁴

Maintien isotherme Périodes t₂, t₃, t₄, t₅ Isothermal maintenance Periods t ₂ , t ₃ , t ₄ , t ₅

Deuxième paire P₂ de cabestans période t₂
Diamètre des cabestans à l'entrée du fil : De = 1500 mm
Diamètre des cabestans à la sortie du fil : Ds = 1500 mm
Entre-axe des cabestans : E = 1575 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 11 mm
Largeur des gorges : J = 2,3 mm
Vitesse de rotation du cabestan 2 : 192 tours/minute.
Temps de séjour : t₂ = 1,26 secondes
Nombre de spires : 2
La température du fil a été maintenue à 580 ± 5°C. Les cabestans ont été maintenus à une température de 549°C à l'aide d'un débit d'eau à 25°C de : 0,4 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 123 mm paramètres principaux de l'élément de transfert thermique :
K₁ = 0,488
K₂ = 0,952
K₃ = 0
K₄ = 6,54x10⁻³
Troisième paire P₃ de cabestans période t₃
Diamètre des cabestans à l'entrée du fil : De = 1500 mm
Diamètre des cabestans à la sortie du fil : Ds = 1500 mm
Entre-axe des cabestans : E = 1575 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 11 mm
Largeur des gorges : J = 2,3 mm
Vitesse de rotation du cabestan 2 : 192 tours/minute
Temps de séjour : t₃ = 1,26 secondes
Nombre de spires : 2
La température du fil a été maintenue à 580 ± 6°C
Les cabestans ont été maintenus à une température de : 436°C à
l'aide d'un débit d'eau à 25°C de : 1,85 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 20 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,488
K₂ = 0,952
K₃ = 0
K₄ = 1,06x10⁻³
Quatrième paire P₄ de cabestans période t₄
Identique à la deuxième paire de cabestans
Cinquième paire P₅ de cabestans période t₅
Diamètre des cabestans à l'entrée du fil : De = 900 mm
Diamètre des cabestans à la sortie du fil : Ds = 900 mm
Entre-axe des cabestans : E = 945 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 11 mm
Largeur des gorges : J = 3 mm
Vitesse de rotation du cabestan 2 : 320 tours/minute.
Temps de séjour : t₅ = 1,51 secondes
Nombre de spires : 4
La température du fil a été maintenue à 580 ± 2°C.Second pair P₂ of capstans period t₂
Diameter of the capstans at the wire entry: D e = 1500 mm
Diameter of the capstans at the wire outlet: D s = 1500 mm
Center distance of capstans: E = 1575 mm
Capstan recovery rate: T r = 0.898
Groove pitch: p = 11 mm
Groove width: J = 2.3 mm
Rotation speed of capstan 2: 192 revolutions / minute.
Residence time: t₂ = 1.26 seconds
Number of turns: 2
The wire temperature was maintained at 580 ± 5 ° C. The capstans were kept at a temperature of 549 ° C using a water flow at 25 ° C of: 0.4 m³ / h
Thickness of the thermal coupling gas slide: H = 123 mm main parameters of the heat transfer element:
K₁ = 0.488
K₂ = 0.952
K₃ = 0
K₄ = 6.54x10⁻³
Third pair P₃ of capstans period t₃
Diameter of the capstans at the wire entry: D e = 1500 mm
Diameter of the capstans at the wire outlet: Ds = 1500 mm
Center distance of capstans: E = 1575 mm
Capstan recovery rate: T r = 0.898
Groove pitch: p = 11 mm
Groove width: J = 2.3 mm
Rotation speed of capstan 2: 192 rpm
Residence time: t₃ = 1.26 seconds
Number of turns: 2
The wire temperature was kept at 580 ± 6 ° C
The capstans were kept at a temperature of: 436 ° C at
using a water flow at 25 ° C of: 1.85 m³ / h
Thickness of the thermal coupling gas slide: H = 20 mm
Main parameters of the heat transfer element:
K₁ = 0.488
K₂ = 0.952
K₃ = 0
K₄ = 1.06x10⁻³
Fourth pair P₄ of capstans period t₄
Identical to the second pair of capstans
Fifth pair P₅ of capstans period t₅
Diameter of capstans at the entry of the wire: D e = 900 mm
Diameter of capstans at the outlet of the wire: D s = 900 mm
Center distance of capstans: E = 945 mm
Capstan recovery rate: T r = 0.898
Groove pitch: p = 11 mm
Groove width: J = 3 mm
Rotation speed of capstan 2: 320 rpm.
Residence time: t₅ = 1.51 seconds
Number of turns: 4
The wire temperature was maintained at 580 ± 2 ° C.

Les cabestans ont été maintenus à une température de : 585 ± 5°C grâce aux résistances électriques 38, la circulation d'eau a été coupée.The capstans were kept at a temperature of: 585 ± 5 ° C thanks to the electrical resistances 38, the water circulation was cut off.

L'épaisseur H de la lame de gaz de couplage thermique a été maintenue au maximum afin de limiter la consommation d'électricité soit : H = 50 mm.The thickness H of the thermal coupling gas blade was kept to the maximum in order to limit the consumption of electricity, ie: H = 50 mm.

Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,0233
K₂ = 0,952
K₃ = 0
K₄ = 0,062Main parameters of the heat transfer element:
K₁ = 0.0233
K₂ = 0.952
K₃ = 0
K₄ = 0.062

Refroidissement final période t₆ Final cooling period t ₆

Sixième paire P₆ de cabestans
Diamètre des cabestans à l'entrée du fil : De = 1500 mm
Diamètre des cabestans à la sortie du fil : Ds = 1489 mm
Entre-axe des cabestans : E = 1575 mm
Taux de recouvrement des cabestans : Tr = 0,894
Pas des gorges : p = 11 mm
Largeur des gorges : J = 2,3 mm
Vitesse de rotation du cabestan 2 : 192 tours/minute
Temps de séjour : t₆ = 4,4 secondes
Nombre de spires : 7
Température initiale du fil : Tf₂ = 580°C
Température finale du fil : Tf₃ = 211°C
Les cabestans ont été maintenus à une température de : 170°C à
l'aide d'un débit d'eau à 25°C de : 5,88 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 1,7 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,488
K₂ = 0,952
K₃ = 0,74
K₄ = 9,04x10⁻⁵
Après traitement thermique, le fil 4 a une résistance à la rupture en traction de 1200 MPa.Sixth P₆ pair of capstans
Diameter of the capstans at the wire entry: D e = 1500 mm
Diameter of the capstans at the wire outlet: D s = 1489 mm
Center distance of capstans: E = 1575 mm
Capstan recovery rate: Tr = 0.894
Groove pitch: p = 11 mm
Groove width: J = 2.3 mm
Rotation speed of capstan 2: 192 rpm
Residence time: t₆ = 4.4 seconds
Number of turns: 7
Initial wire temperature: Tf₂ = 580 ° C
Final wire temperature: Tf₃ = 211 ° C
The capstans were kept at a temperature of: 170 ° C at
using a water flow at 25 ° C of: 5.88 m³ / h
Thickness of the thermal coupling gas slide: H = 1.7 mm
Main parameters of the heat transfer element:
K₁ = 0.488
K₂ = 0.952
K₃ = 0.74
K₄ = 9.04x10⁻⁵
After heat treatment, the wire 4 has a tensile strength of 1200 MPa.

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,28 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 3050 MPa
R = 42,72
ε = 3,75This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.28 mm. The tensile strength for this drawn wire is 3050 MPa
R = 42.72
ε = 3.75

Exemple 4Example 4

Cet exemple est identique au précédent à l'exception du fait que l'on utilise un acier du type 2 au lieu d'un acier du type 1. Le temps d'incubation et le temps de transformation sont sensiblement les mêmes que dans l'exemple précédent.This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel. The incubation time and the transformation time are substantially the same as in previous example.

Après traitement thermique, le fil a une résistance à la rupture en traction de 1 345 MPa.After heat treatment, the wire has a tensile breaking strength of 1345 MPa.

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,28 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 3 480 MPa
R = 42,72
ε = 3,75This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.28 mm. The tensile strength for this drawn wire is 3,480 MPa
R = 42.72
ε = 3.75

Exemple 5Example 5

Les conditions de cet exemple sont les suivantes :

  • Acier type 1
  • Temps d'incubation = 3,5 secondes environ
  • Temps de transformation = 3 secondes environ
  • Diamètre du fil : Df = 2,35 mm
  • Vitesse V de défilement du fil : 15 m/s
  • Gaz 27 :
    • . Pour les éléments de transfert thermique 1 à 4 et 6 : H₂ pur,
    • . Pour l'élément de maintien isotherme 5 : N₂ pur,
    • . Un seul gaz est utilisé pour chaque élément de transfert thermique, dans un but de simplification technologique.
The conditions of this example are as follows:
  • Type 1 steel
  • Incubation time = approximately 3.5 seconds
  • Processing time = about 3 seconds
  • Wire diameter: D f = 2.35 mm
  • Wire feed speed V: 15 m / s
  • Gas 27:
    • . For heat transfer elements 1 to 4 and 6: pure H₂,
    • . For the isothermal holding element 5: pure N₂,
    • . A single gas is used for each heat transfer element, for the purpose of technological simplification.

Refroidissement primaire période t1Primary cooling period t1

Première paire P₁ de cabestans
Diamètre des cabestans à l'entrée du fil : De = 2114 mm,
Diamètre des cabestans à la sortie du fil : Ds = 2100 mm
Entre-axe des cabestans : E = 2210 mm
Taux de recouvrement des cabestans : Tr = 0,8996
Pas des gorges : p = 12 mm
largeur des gorges : J = 2,7 mm
Vitesse de rotation du cabestan 2 : 136 tours/minute
Temps de séjour : t₁ = 3,54 secondes
Nombre de spires : 4
Température initiale du fil : Tf₁ = 930°C
Température finale du fil : Tf₂ = 580°C
Les cabestans ont été maintenus à une température de : 558°C à
l'aide d'un débit d'eau à 25°C de : 9,95 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 10 mm
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,51
K₂ = 0,957
K₃ = 0,667
K₄ = 4,44x10⁻⁴First P₁ pair of capstans
Diameter of the capstans at the entry of the wire: D e = 2114 mm,
Diameter of the capstans at the wire outlet: D s = 2100 mm
Center distance of capstans: E = 2210 mm
Capstan recovery rate: T r = 0.8996
Groove pitch: p = 12 mm
groove width: J = 2.7 mm
Rotation speed of capstan 2: 136 rpm
Residence time: t₁ = 3.54 seconds
Number of turns: 4
Initial wire temperature: Tf₁ = 930 ° C
Final wire temperature: Tf₂ = 580 ° C
The capstans were kept at a temperature of: 558 ° C at
using a water flow at 25 ° C of: 9.95 m³ / h
Thickness of the thermal coupling gas slide: H = 10 mm
Main parameters of the heat transfer element:
K₁ = 0.51
K₂ = 0.957
K₃ = 0.667
K₄ = 4.44x10⁻⁴

Maintien isotherme Périodes t₂, t₃, t₄, t₅ Isothermal maintenance Periods t ₂ , t ₃ , t ₄ , t ₅

Deuxième paire P₂ de cabestans période t₂
Diamètre des cabestans à l'entrée du fil : De = 2100 mm
Diamètre des cabestans à la sortie du fil : Ds = 2100 mm
Entre-axe des cabestans : E = 2210 mm
Taux de recouvrement des cabestans : Tr = 0,896
Pas des gorges : p = 12 mm
largeur des gorges : J = 2,7 mm
Vitesse de rotation du cabestan 2 : 137 tours/minute
Temps de séjour : t₂ = 1,77 secondes
Nombre de spires : 2
La température du fil a été maintenue à 580 ± 5°C
Les cabestans ont été maintenus à une température de : 550°C à
l'aide d'un débit d'eau à 25°C de : 0,66 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 147 mm.Second pair P₂ of capstans period t₂
Diameter of the capstans at the entry of the wire: D e = 2100 mm
Diameter of the capstans at the wire outlet: D s = 2100 mm
Center distance of capstans: E = 2210 mm
Capstan recovery rate: T r = 0.896
Groove pitch: p = 12 mm
groove width: J = 2.7 mm
Capstan 2 rotation speed: 137 rpm
Residence time: t₂ = 1.77 seconds
Number of turns: 2
The wire temperature was kept at 580 ± 5 ° C
The capstans were kept at a temperature of: 550 ° C at
using a water flow at 25 ° C of: 0.66 m³ / h
Thickness of the thermal coupling gas blade: H = 147 mm.

Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,51
K₂ = 0,95
K₃ = 0
K₄ = 6,57x10⁻³
Troisième paire P₃ de cabestans période t₃
Diamètre des cabestans à l'entrée du fil : De = 2100 mm,
Diamètre des cabestans à la sortie du fil : Ds = 2100 mm
Entre-axe des cabestans : E = 2210 mm
Taux de recouvrement des cabestans : Tr = 0,896
Pas des gorges : p = 12 mm
largeur des gorges : J = 2,7 mm
Vitesse de rotation du cabestan 2 : 137 tours/minute
Temps de séjour : t₃ = 1,77 secondes
Nombre de spires : 2
La température du fil a été maintenue à 580 ± 6°C
Les cabestans ont été maintenus à une température de : 443°C à
l'aide d'un débit d'eau à 25°C de : 3 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 25 mm.
Main parameters of the heat transfer element:
K₁ = 0.51
K₂ = 0.95
K₃ = 0
K₄ = 6.57x10⁻³
Third pair P₃ of capstans period t₃
Diameter of the capstans at the entry of the wire: D e = 2100 mm,
Diameter of the capstans at the wire outlet: D s = 2100 mm
Center distance of capstans: E = 2210 mm
Capstan recovery rate: T r = 0.896
Groove pitch: p = 12 mm
groove width: J = 2.7 mm
Capstan 2 rotation speed: 137 rpm
Residence time: t₃ = 1.77 seconds
Number of turns: 2
The wire temperature was kept at 580 ± 6 ° C
The capstans were kept at a temperature of: 443 ° C at
using a water flow at 25 ° C of: 3 m³ / h
Thickness of the thermal coupling gas slide: H = 25 mm.

Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,51
K₂ = 0,95
K₃ = 0
K₄ = 1,12x10⁻³
Quatrième paire P₄ de cabestans période t₄
Identique à la deuxième paire P₂ de cabestans
Cinquième paire P₅ de cabestans période t₅
Diamètre des cabestans à l'entrée du fil : De = 1200 mm
Diamètre des cabestans à la sortie du fil : Ds = 1200 mm
Entre-axe des cabestans : E = 1260 mm
Taux de recouvrement des cabestans : Tr = 0,898
Pas des gorges : p = 12 mm
Largeur des gorges : J = 4,5 mm
Vitesse de rotation du cabestan 2 : 239 tours/minute.
Temps de séjour : t₅ = 2 secondes
Nombre de spires : 4
La température du fil a été maintenue à 580 ± 2°C
Les cabestans ont été maintenus à une température de : 585 ± 5°C grâce aux résistances électriques 38, la circulation d'eau a été coupée.Main parameters of the heat transfer element:
K₁ = 0.51
K₂ = 0.95
K₃ = 0
K₄ = 1.12x10⁻³
Fourth pair P₄ of capstans period t₄
Identical to the second P₂ pair of capstans
Fifth pair P₅ of capstans period t₅
Diameter of the capstans at the wire entry: D e = 1200 mm
Diameter of the capstans at the outlet of the wire: D s = 1200 mm
Center distance of capstans: E = 1260 mm
Capstan recovery rate: T r = 0.898
Groove pitch: p = 12 mm
Groove width: J = 4.5 mm
Rotation speed of capstan 2: 239 rpm.
Residence time: t₅ = 2 seconds
Number of turns: 4
The wire temperature was kept at 580 ± 2 ° C
The capstans were kept at a temperature of: 585 ± 5 ° C thanks to the electrical resistances 38, the water circulation was cut off.

L'épaisseur H de la lame de gaz de couplage thermique a été maintenue au maximum afin de limiter la consommation d'électricité soit : H = 100 mm.
Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,01
K₂ = 0,952
K₃ = 0
K₄ = 0,115The thickness H of the thermal coupling gas blade was kept to the maximum in order to limit the consumption of electricity, ie: H = 100 mm.
Main parameters of the heat transfer element:
K₁ = 0.01
K₂ = 0.952
K₃ = 0
K₄ = 0.115

Refroidissement final période t₆ Final cooling period t ₆

Sixième paire P₆ de cabestans
Diamètre des cabestans à l'entrée du fil : De = 2100 mm,
Diamètre des cabestans à la sortie du fil : Ds = 2085 mm
Entre-axe des cabestans : E = 2210 mm
Taux de recouvrement des cabestans : Tr = 0,8645
Pas des gorges : p = 12 mm
largeur des gorges : J = 2,7 mm
Vitesse de rotation du cabestan 2 : 137 tours/minute
Temps de séjour : t₆ = 5,28 secondes
Nombre de spires : 6
Température initiale du fil : Tf2 = 580°C
Température finale du fil : Tf3 = 204°C
Les cabestans ont été maintenus à une température de : 170°C à
l'aide d'un débit d'eau à 25°C de : 9,5 m³/h
Epaisseur de la lame de gaz de couplage thermique : H = 2,2 mm.Sixth P₆ pair of capstans
Diameter of the capstans at the entry of the wire: D e = 2100 mm,
Diameter of capstans at the outlet of the wire: D s = 2085 mm
Center distance of capstans: E = 2210 mm
Capstan recovery rate: T r = 0.8645
Groove pitch: p = 12 mm
groove width: J = 2.7 mm
Capstan 2 rotation speed: 137 rpm
Residence time: t₆ = 5.28 seconds
Number of turns: 6
Initial wire temperature: T f2 = 580 ° C
Final wire temperature: T f3 = 204 ° C
The capstans were kept at a temperature of: 170 ° C at
using a water flow at 25 ° C of: 9.5 m³ / h
Thickness of the thermal coupling gas slide: H = 2.2 mm.

Paramètres principaux de l'élément de transfert thermique :
K₁ = 0,511
K₂ = 0,95
K₃ = 0,72
K₄ = 9,84x10⁻⁵
Après traitement thermique, le fil 4 a une résistance à la rupture en traction de 1 195 MPa.Main parameters of the heat transfer element:
K₁ = 0.511
K₂ = 0.95
K₃ = 0.72
K₄ = 9.84x10⁻⁵
After heat treatment, the wire 4 has a tensile strength of 1,195 MPa.

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,35 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 2 950 MPa
R = 45,1
ε = 3,81This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.35 mm. The tensile strength for this drawn wire is 2,950 MPa
R = 45.1
ε = 3.81

Exemple 6Example 6

Cet exemple est identique au précédent à l'exception du fait que l'on utilise un acier du type 2 au lieu d'un acier du type 1. Le temps d'incubation et le temps de transformation sont sensiblement les mêmes que dans l'exemple précédent.This example is identical to the previous one except that a type 2 steel is used instead of a type 1 steel. The incubation time and the transformation time are substantially the same as in previous example.

Après traitement thermique le fil a une résistance à la rupture en traction de 1 355 MPa.After heat treatment, the wire has a tensile strength of 1355 MPa.

Ce fil est ensuite laitonné puis tréfilé de façon connue pour obtenir un diamètre final de 0,35 mm. La résistance à la rupture en traction pour ce fil tréfilé est de 3 510 MPa.
R = 45,1
ε = 3,81This wire is then brass plated and then drawn in a known manner to obtain a final diameter of 0.35 mm. The tensile strength for this drawn wire is 3,510 MPa.
R = 45.1
ε = 3.81

Exemple 7Example 7

Cet exemple est identique à l'exemple 1 à l'exception du fait que l'on utilise un acier du type 1 du point de vue composition mais avec un temps d'incubation de 3,8 secondes et un temps de transformation de 3,8 secondes à 580°C.This example is identical to Example 1 with the exception that a type 1 steel is used from the composition point of view but with an incubation time of 3.8 seconds and a transformation time of 3, 8 seconds at 580 ° C.

L'installation est identique à celle utilisée pour l'exemple 1 à part le nombre de spires qui est passé de 7 à 8 sur la première paire P₁ de cabestans, de 3 à 4 sur la troisième paire P₃ de cabestans.The installation is identical to that used for Example 1 except for the number of turns which went from 7 to 8 on the first pair P₁ of capstans, from 3 to 4 on the third pair P₃ of capstans.

Les résistances à la rupture après traitement thermique et après tréfilage ne diffèrent pas de plus de 2 % de celles de l'exemple 1The tensile strengths after heat treatment and after drawing do not differ by more than 2% from those of Example 1

Exemple 8Example 8

Cet exemple est identique à l'exemple 6 à l'exception du fait que l'on utilise un acier du type 2 du point de vue composition mais avec un temps d'incubation de 4,4 secondes et un temps de transformation de 6 secondes à 580°C.This example is identical to Example 6 except that a type 2 steel is used from the composition point of view but with an incubation time of 4.4 seconds and a transformation time of 6 seconds. at 580 ° C.

L'installation est identique à celle de l'exemple 6 à part le nombre de spires qui est passé de 4 à 5 sur la première paire P₁ de cabestans, de 2 à 3 sur la troisième paire P₃ de cabestans.The installation is identical to that of Example 6 except for the number of turns which went from 4 to 5 on the first P₁ pair of capstans, from 2 to 3 on the third P₃ pair of capstans.

Les résistances à la rupture après traitement thermique et après tréfilage ne diffèrent pas de plus de 2 % de celles de l'exemple 1The tensile strengths after heat treatment and after drawing do not differ by more than 2% from those of Example 1

Exemple 9Example 9

Cet exemple est identique à l'exemple 2 à l'exception du fait que l'on utilise un acier du type 2 du point de vue composition mais avec un temps d'incubation de 4 secondes et un temps de transformation de 3 secondes à 580°C.This example is identical to Example 2 except for the fact that a type 2 steel is used from the composition point of view but with an incubation time of 4 seconds and a transformation time of 3 seconds at 580 ° C.

Dans cet exemple, la régulation automatique a fait passer la deuxième paire P₂ de cabestans en mode chauffage, c'est-à-dire que la circulation d'eau de refroidissement a été coupée et les résistances électriques de chauffage 38 ont été mises en service de façon à éviter le refroidissement du fil qui se serait produit sur la deuxième paire de cabestans entre l'arrivée du fil et le moment ou celui-ci est le siège d'un dégagement de chaleur dû à la transformation de l'austénite en perlite.In this example, the automatic regulation put the second pair P₂ of capstans in heating mode, that is to say that the cooling water circulation was cut off and the electric heating resistors 38 were put into service. so as to avoid the cooling of the wire which would have occurred on the second pair of capstans between the arrival of the wire and the moment when it is the seat of a release of heat due to the transformation of the austenite into perlite .

Les résistances à la rupture après traitement thermique et après tréfilage ont diminué de moins de 2 % par rapport à celles de l'exemple 2, ce qui est dû au fait d'une isothermicité un peu moins bonne.The tensile strengths after heat treatment and after wire drawing decreased by less than 2% compared to those of Example 2, which is due to the fact of a slightly poorer isothermicity.

L'adaptabilité peut être améliorée en améliorant l'isothermicité, c'est-à-dire en augmentant le nombre de paires de cabestans, mais le faible gain en résistance du fil que l'on peut en attendre ne justifie pas en général la dépense effectuée.The adaptability can be improved by improving the isothermicity, that is to say by increasing the number of pairs of capstans, but the small gain in resistance of the wire which one can expect from it does not generally justify the expense. performed.

Le fil 4 traité conformément à l'invention dans l'installation 100 comporte la même structure que celle qu'on obtient par le procédé connu de patentage au plomb, c'est-à-dire une structure perlitique fine. Cette structure comporte des lamelles de cémentite séparées par des lamelles de ferrite. A titre d'exemple, la figure 10 représente en coupe une portion 70 d'une telle structure perlitique fine. Cette portion 70 comporte deux lamelles de cémentite 71, pratiquement parallèles, séparées par une lamelle de ferrite 72. L'épaisseur des lamelles de cémentite 71 est représentée par "i" et l'épaisseur des lamelles de ferrite 72 est représentée par "e". La structure perlitique est fine, c'est-à-dire que la valeur moyenne de la somme i + e est au plus égale à 1000 Å, avec un écart type de 250 Å.The wire 4 treated in accordance with the invention in the installation 100 has the same structure as that obtained by the known lead patenting process, that is to say a fine pearlitic structure. This structure includes cementite lamellae separated by ferrite lamellae. By way of example, FIG. 10 represents in section a portion 70 of such a fine pearlitic structure. This portion 70 comprises two substantially parallel cementite strips 71, separated by a ferrite strip 72. The thickness of the cementite strips 71 is represented by "i" and the thickness of the ferrite strips 72 is represented by "e" . The pearlitic structure is fine, that is to say that the average value of the sum i + e is at most equal to 1000 Å, with a standard deviation of 250 Å.

Bien entendu, l'invention n'est pas limitée aux exemples de réalisation précédemment décrits.Of course, the invention is not limited to the embodiments described above.

Claims (20)

  1. A method for the thermal treatment of at least one metal wire by means of capstans, in which the wire is passed over at least two heat-conducting capstans having grooves, the wire being reeved, crossed in these grooves, the width of the grooves being slightly greater than that of the wire, a gas, within the grooves, being in contact with the wire and the capstans;
       this method being characterised by the following features:
    (a) the capstans are heated or cooled by means of the gas also arranged between the capstans and at least one part, this gas being in contact with the capstans and the part, said heat-conductive part being located outside the capstans, by causing a heat-exchange fluid other than the gas to flow in contact with the part so that heat exchanges take place, on the one hand, between the gas and the part and, on the other hand, between the part and the fluid;
    (b) the thickness of the layer of gas between the capstans and the part is adjusted as a function of the thermal treatment to be carried out.
  2. A method according to Claim 1, characterised in that the layer of gas, between the capstans and the part, is located between a substantially flat face of the part and substantially flat faces of the capstans, these faces of the capstans being arranged substantially in one and the same plane which is perpendicular to the axes of rotation of the capstans and substantially parallel to the face of the part.
  3. A method according to any one of Claims 1 or 2, characterised in that the gas arranged between the capstans and the part suffers practically no movements other than those which are due to the rotation of the capstans.
  4. A method according to any one of claims 1 to 3 for thermally treating at least one carbon steel wire so as to obtain a fine perlitic structure, this method comprising an austenitisation treatment in which the wire is heated to a temperature above the AC3 transformation temperature in order to obtain a homogeneous austenite structure, and a perlitisation treatment in which the wire is then cooled in order to obtain a metastable austenite structure which is transformed into perlite.
  5. A method according to Claim 4, characterised in that at least one pair of capstans is used upon the cooling in order to obtain a metastable austenite structure in such a manner as to have the following relationships:

    K1 ≧ 0.3   (1)
    Figure imgb0039

    K2 ≧ 0.85   (2)
    Figure imgb0040

    0.5 ≦ K3 ≦ 1.5   (3)
    Figure imgb0041

    2x10⁻⁴ ≦ K4 ≦ 6x10⁻⁴   (4)
    Figure imgb0042

    with, by definition:

    K1 = L/(JxDf - Df²)   (5)
    Figure imgb0043

    K2 = De/E   (6)
    Figure imgb0044

    K3 = 100 (De/Ds - 1)   (7)
    Figure imgb0045

    K4 = (VxDf²xH)/(LxDe²)   (8)
    Figure imgb0046

    in which L, is the thermal conductivity of the gas present in the grooves and between the capstans and the part, L being determined at 600°C and expressed in watts.m⁻¹.°K⁻¹; Df is the diameter of the wire expressed in millimetres; J is the width of the grooves expressed in millimetres; E is the distance from centre-to-centre of the two capstans, expressed in millimetres; De is the diameter of winding of the wire at the entrance of any capstan; Ds is the diameter of winding of the wire at the outlet from the same capstan, De and Ds being expressed in millimetres; V is the speed of passage of the wire, expressed in metres per second; H is the thickness of the layer of gas between the capstans and the part, expressed in millimetres, this gas suffering practically no movements other than those which are due to the rotation of the capstans.
  6. A method according to Claim 5, characterised in that furthermore at least one pair of capstans is used upon the transformation of austenite into perlite so that the temperature of the wire does not change by more than 10°C plus or minus from a given temperature obtained after the cooling giving a metastable austenite structure, and this for a period of time greater than the perlitisation time, the following relationships being present for at least one pair of capstans:

    K2 ≧ 0.85   (9)
    Figure imgb0047

    K3 = 0   (10)
    Figure imgb0048

    the gas between the capstans and the part, in the case of this pair, suffering practically no movements other than those which are due to the rotation of the capstans.
  7. A method according to Claim 6, characterised in that the following relationships are present for at least one pair of capstans upon the transformation of austenite into perlite:

    K1 ≧ 0.3   (11)
    Figure imgb0049

    0.5x10⁻³ ≦ K4 ≦ 9x10⁻³   (12)
    Figure imgb0050

    the gas between the capstans and the part, in the case of this pair, suffering practically no movements other than those which are due to the rotation of the capstans.
  8. A method according to any one of Claims 5 to 7, characterised in that at least one pair of capstans is used in order to cool the wire after the perlitisation treatment.
  9. A device for the thermal treatment of at least one metal wire by means of capstans, the device having at least two heat-conductive capstans which have grooves, the device furthermore comprising means making it possible to pass the wire in the grooves of the capstans, the wire being reeved, crossed in these grooves, the width of the grooves being slightly greater than that of the wire, and a gas, within the grooves, in contact with the wire and the capstans; the device being characterised by the following features:
    (a) it comprises means permitting the heating or cooling of the capstans, said means comprising:
    - at least one heat-conductive part located on the outside of the capstans;
    - means making it possible to cause a heat-exchange fluid other than the gas to circulate in contact with the part;
    - the gas arranged also between the capstans and the part, in contact with the capstans and the part; these means being so arranged that thermal exchanges take place, on the one hand, between the gas and the part and, on the other hand, between the part and the fluid;
    (b) it comprises means making it possible to regulate the thickness of the layer of gas between the capstans and the part as a function of the heat treatment to be carried out.
  10. A device according to Claim 9, characterised in that the layer of gas, between the capstans and the part, is located between a substantially flat face of the part and substantially flat faces of the capstans, these faces of the capstans being arranged substantially in one and the same plane which is perpendicular to the axes of rotation of the capstans and substantially parallel to the face of the part.
  11. A device according to any one of Claims 9 or 10, characterised in that the gas arranged between the capstans and the part suffers practically no movements other than those which are due to the rotation of the capstans.
  12. A device according to any one of Claims 9 to 11, characterised in that, for each capstan, the grooves have the axis of the capstan as their axis.
  13. A device according to any one of Claims 9 to 12, characterised in that one of the capstans turns freely about its axis as a result of the traction of the wire and in that the grooves of this capstan are located on heat-conductive rings, said rings being arranged on the body of the capstan and being adapted to turn about the axis of the capstan independently of the body.
  14. A device according to any one of Claims 9 to 13 characterised in that, on at least one capstan, the winding diameter of the wire varies between the entrance and the outlet of the capstan.
  15. An installation for the treatment of at least one metal wire, comprising at least one device according to any one of Claims 9 to 14.
  16. An installation according to Claim 15, characterised in that it is intended for the thermal treatment of at least one carbon steel wire in order to obtain a fine perlitic structure by an austenitisation treatment, in which the wire is heated to a temperature above the AC3 transformation temperature in order to obtain a homogeneous austenite structure, and a perlitisation treatment in which the wire is then cooled in order to obtain a metastable austenite structure which is transformed into perlite, at least one device being intended for the perlitisation treatment.
  17. An installation according to Claim 16, characterised in that at least one device is intended to cool the wire in order to obtain a metastable austenite structure, this device having the following relationships:

    K1 ≧ 0.3   (1)
    Figure imgb0051

    K2 ≧ 0.85   (2)
    Figure imgb0052

    0.5 ≦ K3 ≦ 1.5   (3)
    Figure imgb0053

    2x10⁻⁴ ≦ K4 ≦ 6x10⁻⁴   (4)
    Figure imgb0054

    with, by definition:

    K1 = L/(JxDf - Df²)   (5)
    Figure imgb0055

    K2 = De/E   (6)
    Figure imgb0056

    K3 = 100 (De/Ds - 1)   (7)
    Figure imgb0057

    K4 = (VxDf²xH)/(LxDe²)   (8)
    Figure imgb0058

    in which L is the thermal conductivity of the gas present in the grooves and between the capstans and the part, L being determined at 600°C and expressed in watts.m⁻¹.°K⁻¹; Df is the diameter of the wire, expressed in millimetres; J is the width of the grooves, expressed in millimetres; E is the centre-to-centre distance of the two capstans, expressed in millimetres; De is the diameter of winding of the wire at the entrance of any capstan; Ds is the diameter of winding of the wire at the outlet from the same capstan, De and Ds being expressed in millimetres; V is the speed of passage of the wire, expressed in metres per second; H is the thickness of the layer of gas between the capstans and the part, expressed in millimetres, the gas between the capstans and the part, in the case of this device, suffering practically no movements other than those which are due to the rotation of the capstans.
  18. An installation according to Claim 17, characterised in that at least one device is intended to permit the transformation of metastable austenite into perlite, in such a manner that the temperature of the wire does not vary by more than 10°C plus or minus from a given temperature obtained after the cooling, giving a metastable austenite structure, and this for a time greater than the perlitisation time, the following relationships being present in the case of at least one device:

    K2 ≧ 0.85   (9)
    Figure imgb0059

    K3 = 0   (10)
    Figure imgb0060

    the gas between the capstans and the part, in the case of this device, suffering practically no movements other than those which are due to the rotation of the capstans.
  19. An installation according to Claim 18, characterised in that at least one device intended to permit the transformation of metastable austenite into perlite has the following relationships;

    K1 ≧ 0.3   (11)
    Figure imgb0061

    0.5x10⁻³ ≦ K4 ≦ 9 x 10⁻³   (12),
    Figure imgb0062

    the gas between the capstans and the part, in the case of this device, suffering practically no movements other than those which are due to the rotation of the capstans.
  20. An installation according to any one of Claims 16 to 19, characterised in that at least one device is intended to cool the wire, after perlitisation.
EP90913487A 1989-09-19 1990-09-07 Processes and devices for the heat treatment of metal wires by bringing them around capstans Expired - Lifetime EP0493424B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR8912384 1989-09-19
FR8912384A FR2652094B1 (en) 1989-09-19 1989-09-19 METHODS AND DEVICES FOR THERMALLY TREATING METAL WIRE BY PASSING IT ON CAPSTANS.
PCT/FR1990/000592 WO1991004345A1 (en) 1989-09-19 1990-09-07 Processes and devices for the heat treatment of metal wires by bringing them around capstans

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EP0493424A1 EP0493424A1 (en) 1992-07-08
EP0493424B1 true EP0493424B1 (en) 1994-07-27

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EP90913487A Expired - Lifetime EP0493424B1 (en) 1989-09-19 1990-09-07 Processes and devices for the heat treatment of metal wires by bringing them around capstans

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US (1) US5251881A (en)
EP (1) EP0493424B1 (en)
JP (1) JP2895223B2 (en)
AU (1) AU6400090A (en)
BR (1) BR9007663A (en)
CA (1) CA2065316A1 (en)
DE (1) DE69011126T2 (en)
FR (1) FR2652094B1 (en)
WO (1) WO1991004345A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2650296B1 (en) * 1989-07-26 1991-10-11 Michelin & Cie METHOD AND DEVICE FOR HEAT TREATING AT LEAST ONE METAL WIRE WITH THERMAL TRANSFER PLATES
US6629361B1 (en) * 1999-07-30 2003-10-07 Electrovations Method of producing a high temperature electrical conductor
US7832250B2 (en) * 2008-04-18 2010-11-16 L&P Property Management Company Method and apparatus for automating production of sinuous springs

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE34829C (en) * A. SCHRÄDER, Regierungs - Maschinenbauführer in Telgte i. Westph Power-collecting brake
US2965368A (en) * 1953-08-14 1960-12-20 Vaughn Machinery Co Wire treating apparatus
US3021128A (en) * 1955-12-06 1962-02-13 Svenska Metallverken Ab Method and means for continuously annealing metal strips, wire and the like
US4012028A (en) * 1975-05-08 1977-03-15 Vladimir Izrailevich Dunaevsky Furnace of a continuous metal strip heat-treatment plant
DE2701828A1 (en) * 1976-01-19 1977-07-21 Melfo DEVICE FOR DIRECT ANNEALING OF METAL WIRE
JPS5799760A (en) * 1980-12-11 1982-06-21 Matsushita Electric Ind Co Ltd Resin sealing type electronic part
SU1224347A1 (en) * 1981-12-29 1986-04-15 Гомельский Государственный Университет Method of patenting steel wire
AT389322B (en) * 1987-01-09 1989-11-27 Evg Entwicklung Verwert Ges DEVICE FOR HEAT TREATING A CONTINUOUSLY PROGRESSIVE METAL WIRE
JPH06124976A (en) * 1992-10-13 1994-05-06 Nec Corp Tab ic

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
Patent Abstracts of Japan, vol. 12, no 37 (C-473) (2884), 04.02.88, & JP,A,62185835 (KOA KAGAKU KOGYO K.K.) 14.08.87 *
Patent Abstracts of Japan, vol.8, no 67 (C-216) (1504), 29.03.84, & JP,A, 58217640 (SHINKOU KOUSEN KOGYO K.K.) 17.12.83 *

Also Published As

Publication number Publication date
EP0493424A1 (en) 1992-07-08
FR2652094A1 (en) 1991-03-22
DE69011126T2 (en) 1994-12-01
JPH05502058A (en) 1993-04-15
CA2065316A1 (en) 1991-03-20
BR9007663A (en) 1992-09-01
AU6400090A (en) 1991-04-18
US5251881A (en) 1993-10-12
JP2895223B2 (en) 1999-05-24
FR2652094B1 (en) 1993-07-30
WO1991004345A1 (en) 1991-04-04
DE69011126D1 (en) 1994-09-01

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