CN102373325A - Method and device for carrying out uniform heating or differential heating on sheet steel in rapid non-deformation non-oxidation mode - Google Patents
Method and device for carrying out uniform heating or differential heating on sheet steel in rapid non-deformation non-oxidation mode Download PDFInfo
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- CN102373325A CN102373325A CN2010102547594A CN201010254759A CN102373325A CN 102373325 A CN102373325 A CN 102373325A CN 2010102547594 A CN2010102547594 A CN 2010102547594A CN 201010254759 A CN201010254759 A CN 201010254759A CN 102373325 A CN102373325 A CN 102373325A
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Abstract
The invention provides a method and a device for carrying out uniform heating or differential heating on sheet steel in a rapid non-deformation non-oxidation mode. The method is characterized in that: the contact heat transfer between each heating template and the sheet steel to be heated is utilized to realize the rapid heating of the sheet steel to be heated; clamping force of the heating templates is utilized to prevent the deformation of the sheet steel; a protection atmosphere which is formed between the heating templates is utilized to avoid the oxidation of heat exchange surfaces of the heating templates and the sheet steel to be heated; and the contact heat exchange coefficient between different positions of the heat exchange surfaces of the heating template and the sheet steel to be heated is changed to realize the controllable differential heating of the sheet steel to be heated.
Description
Technical field
The invention belongs to iron and steel thermal treatment and field of hot stamping forming, relate in particular to a kind of method and apparatus that can carry out fast, not have distortion, non-oxidation even heating or differential heating tole.
Background technology
Steel-sheet hot stamping and thermal treatment are a kind of in all types of industries field, particularly make field, widely used processing technology at the body of a motor car component.Its technological process comprises 1) tole is heated to specified temperature and 2) the high temperature tole is implemented the shaping of regulation and/or handled operation.The tole heating means all can produce very big influence to the efficient of hot stamping or thermal treatment process and operability and to the quality of final part.At present the tole heating means mainly contain three kinds of box-type furnace heating, flame heating and induction heating, and its common shortcoming is that heat-processed can cause the tole gross distortion.On the other hand, because the box-type furnace rate of heating is slow, be rhythm that cooperates subsequent thermal punching press or heat treatment step and the generation that prevents the decarburization oxidation, its body of heater must be lengthened out and install additional controlled atmosphere device, and this can significantly increase the cost of investment of heating installation.Simultaneously, traditional heating means (comprising above-mentioned three kinds of methods) all can't be implemented the accurately differential heating of control to tole.Differential heating is a kind of accurately controlled non-uniform heating, can be used to realize the steel-sheet selective hardening.Such as; Be heated to some position of steel-sheet more than the austenitizing temperature; All the other positions are heated to below the austenitizing temperature, and integral quenching just can obtain to comprise HS quenched martensite part and high-ductility ferritic composite performance component partly then.Body of a motor car component (like door B post) with composite performance like this can realize protecting occupant and the best fit that absorbs Impact energy, improve the comprehensive safety performance of automobile greatly, therefore have extremely wide application prospect.
Summary of the invention
The purpose of this invention is to provide and a kind ofly can carry out fast, not have distortion, non-oxidation even heating or the method for differential heating and the equipment of realizing this method tole.
For reaching this purpose; The present invention at first provides a kind of quick Contact Heating method; Promptly using a pair of heated die plate that temperature state such as is maintained at will be heated tole clamps; Utilize heated die plate and be heated transmission of heat by contact between the steel plate, utilize the holding force of heated die plate to stop the steel-sheet distortion latter's rapid heating.
For reaching this purpose; The present invention also provides a kind of method that changes above-mentioned heated die plate and be heated contact heat exchange coefficient between the tole; On the heat-transfer surface of heated die plate, form high heat transfer zone and low heat transfer zone, accomplish the controlled differential heating of steel-sheet with this.
For reaching this purpose, the present invention also provides a kind of method that between a pair of heated die plate, forms localised protection atmosphere, with heat-transfer surface that prevents heated die plate and the oxidation that is heated steel plate.
For reaching this purpose; The present invention also provides a kind of tole heating installation that can realize aforesaid method; Can carry out fast, not have distortion, non-oxidation even heating or differential heating to tole, can also accomplish material loading, clamping and the operation of blowing supervisor metallization processes.
Description of drawings
Below in conjunction with accompanying drawing the present invention is further described.
Fig. 1 is a tole Contact Heating method synoptic diagram;
Fig. 2 is the Hardness Distribution on differential heating-quenched nickelclad;
Fig. 3 is tole contact even heating or contact differential heating apparatus embodiments synoptic diagram;
Fig. 4 is the action synoptic diagram of heated die plate shown in Figure 3, shows its 3 different working states: the state that a) connects material, b) clamped condition, and c) the blowing state;
Fig. 5 is shielding gas preheating tubes and the production well synoptic diagram on the heated die plate shown in Figure 3.
Embodiment
Fig. 1 is a tole Contact Heating method synoptic diagram.One is opposite to the heated die plate of being processed by high temperature steel in the first-class temperature heating unit 101 will be heated steel plate 104 clampings under the effect of holding force P.Compare with being heated steel plate 104, heated die plate 101 has enough thickness and thermal capacity, so its temperature fluctuation in heat-processed can be left in the basket and disregards.Heated die plate 101 has the composite heat-exchange surface that is made up of high heat transfer zone 102 and low heat transfer zone 103, and the former and the coefficient of heat transfer that is heated between the steel plate will be apparently higher than the latter.So; Be heated part that steel plate 104 contacts with high heat transfer zone 102 and can be rapidly heated to self temperature near heated die plate 101; And in the same time; Its part that contacts with low heat transfer zone 103 can only be heated to a certain temperature below heated die plate 101 self temperature, thereby forms all accurate controlled high-temperature zone and cold zones of position, size, shape and temperature on the steel plate 104 being heated, and realizes differential heating.Meanwhile, the holding force P that is applied on the heated die plate 101 can stop the distortion that is heated steel plate 104.
High heat transfer zone 102 is parts of unprocessed mistake on heated die plate 101 heat-transfer surfaces, itself and be heated the coefficient of heat transfer between the steel plate 104, h
High, relevant with the holding force P of its smooth finish, planeness and heated die plate 101; Smooth finish and planeness are high more, and holding force P is big more, h
HighJust big more.Low heat transfer zone 103 is to be processed the part that the back forms small pit dot matrix on heated die plate 101 heat-transfer surfaces, itself and be heated the coefficient of heat transfer between the steel plate, h
Low, relevant with the size and the density of these pits; The size of pit is big more, and density is high more, h
LowJust more little.Above-mentioned pit can directly be generated on the heat-transfer surface of heated die plate 101 by the method for machinery or chemistry/electrograving.Low heat transfer zone 103 also can be made up of a whole depressed area simply.In this case, itself and the transmission of heat by contact that is heated between the steel plate 104 are blocked fully, and the coefficient of heat transfer is only relevant with radiative transfer.Through changing h
HighAnd h
LowBetween clamping time of difference and heated die plate can control and be heated the temperature head between the high-temperature zone and cold zone on the steel plate 104; h
HighAnd h
LowBetween difference more little, the clamping time is long more, temperature head is just more little.
Relative position on the heated die plate 101 between high heat transfer zone and the low heat transfer zone, size and area occupied ratio can be set according to concrete detail design and processing requirement.When low heat transfer zone area was set to zero, what 101 pairs of toles of heated die plate carried out was the contact even heating.When low heat transfer zone area greater than zero the time, what 101 pairs of toles of heated die plate carried out is the contact differential heating.
For the validity of checking contact differential heating method, a block length 200mm, it respectively is 250mm that wide 160mm, the tole of thick 2.3mm are clamped in a pair of length and width size, and temperature is between 950 ℃ the template.Respectively producing a length of side in the central position of template is 50mm, and the degree of depth is that the diamond sunk part of 1mm is as the low heat transfer zone on its heat-transfer surface.After keeping 15s under the 4000Pa holding force, the steel plate quilt is from taking out and shrend between the template.Shown in Fig. 2 is the Hardness Distribution on this quenched nickelclad, shape, size and the position of the position of caving on the rhomboid representation template heat-transfer surface that wherein dotted line marked (low heat transfer zone).Can see that the hardness in inner most of zone, rhomboid only has HRC20 or following, but the outside hardness in rhomboid is elevated to more than the HRC55 fast after through a not too wide zone of transition.This result shows that this steel plate is in being heated process; Its part that contacts with the high heat transfer zone of template (beyond the rhomboid) promptly was heated to rapidly more than the austenitizing temperature in 15 seconds; Therefore after quenching, be transformed into the martensitic stucture of high firmness; It then is not heated to austenitizing temperature with the part that the low heat transfer zone (within the rhomboid) of template contacts, and therefore after quenching, still remains on the state of soft ferritic/pearlitic structure.The hardness zone of transition that is positioned at the rhomboid boundary vicinity shows that this zone is heated to austenite/ferritic two-phase region; After the quenching, only wherein austenite changes the martensitic phase of high firmness mutually into.Therefore, hardness increases the increase gradually that shows its martensitic phase (austenite phase) content gradually from inside, rhomboid to the outside, also shows on this steel plate after the differential heating, once to exist a thermograde that outwards raises gradually from the center, rhomboid.
The equipment scheme that is used for implementing above-mentioned contact even heating or differential heating method can have a variety of, and Fig. 3 is one of embodiment, by body of heater 201 with place the heated die plate 101 in it to constitute.The structure of body of heater 201 and common box-type furnace are similar, and its effect is that heating also remains on one to heated die plate 101 to fixed temperature.Difference is that its top has a long and narrow opening for feed 202, and its bottom has a long and narrow discharge port 203.The involutory surface of opening for feed 202, discharge port 203 and heated die plate 101 will be on the same plane that is positioned at body of heater 201 mid-ways.
As shown in Figure 4, four jiaos of heated die plate 101 respectively are equipped with a hinge.Following hinge 105 wherein is connected with the fulcrum 109 that is installed in body of heater outside framework bottom through lower link 106, in order to support the weight of heated die plate 101.Upper hinge 107 wherein links to each other with the oil cylinder (not shown) that is installed in body of heater outside framework top through last connecting rod 108, in order to drive heated die plate 101 accomplish connect material, a series of actions of clamping and blowing.Shown in Fig. 4 a; Oil cylinder through on pull on connecting rod 108 and drive upper hinges 107 and open; The deadweight W that its pulling force L is less than heated die plate 101 makes fulcrum 109 be applied to reactive force L '=L-W on the lower link 106 less than 0; Thereby order down hinge 105 remains on closure state, and heated die plate 101 V-shaped open state make it can catch the steel plate to be heated 104 that is dropped into by opening for feed 202 and be located.Shown in Fig. 4 b; Oil cylinder through under push to connecting rod 108 and drive upper hinges 107 closures; Simultaneously fulcrum 109 is applied to reactive force on the lower link 106 (L '=-L-W＜＜0) also hinge 105 closures down, and and then makes heated die plate 101 that steel plate 104 to be heated is clamped.Shown in Fig. 4 c; Oil cylinder through on pull on connecting rod 108 and drive upper hinges 107 and open; The deadweight W that its pulling force L is greater than heated die plate 101 makes fulcrum 109 be applied to reactive force L '=L-W on the lower link 106 much larger than 0; And then hinge 105 opens simultaneously under the order, emits via discharge port 203 being heated steel plate 104.In above-mentioned action, the stretching degree of upper hinge 107 is by last retaining ring 110 regulations, and the stretching degree of following hinge 105 is then by following retaining ring 111 regulations.
Shown in Fig. 5 is to be positioned at the shielding gas preheating tubes 112 of heated die plate 101 inside and the shielding gas production well 113 on its heat-transfer surface.Shielding gas through preheating tubes 112 preheatings after a plurality of production well 113 get into the space of forming by heated die plate 101 and form localised protection atmosphere, thereby effectively prevent the heat-transfer surface of heated die plate 101 and be heated the oxidation of steel plate 104.Another effect of production well 113 is when heated die plate 101 unclamps blowing, to provide the high pressure gas jet to help to be heated steel plate to break away from heated die plate smoothly.It is enough little in order to avoid influence heated die plate 101 and be heated the heat exchange between the steel plate 104 that the diameter of production well 113 is wanted.
Heating installation shown in Figure 3 can carry out fast, not have distortion, non-oxidation even heating or differential heating to tole.To the tole of thickness less than 2mm, can be shorter than 10s heat-up time, can adapt to the rhythm of production of hot stamping technology well.
Requiring emphasis is pointed out that, the specific embodiment that provides above is merely the convenient the present invention's of elaboration principle of work.The principle of work that the implementer can use the present invention above-mentioned specific embodiment is carried out diversified modification and details perfect.But all embodiment mutation that so produce all belong to particular embodiment of the present invention, therefore also are comprised in claims of the present invention in the desired interest field.
Claims (8)
1. one kind can be carried out fast, not have the method for being out of shape even heating to tole; It is characterized in that this tole is clamped in a pair of heated die plate that temperature state such as is in; This heated die plate has the heat exchange surface of smooth homogeneity; Utilize heated die plate and be heated transmission of heat by contact between the steel plate, utilize the holding force of heated die plate to stop the distortion that is heated steel plate latter's rapid and uniform heating.
2. one kind can be carried out fast, not have the method for being out of shape differential heating to tole; It is characterized in that this tole is clamped in a pair of heated die plate that temperature state such as is in; This heated die plate has the composite heat-exchange surface that is made up of high heat transfer zone and low heat transfer zone; Utilize this composite heat-exchange surface different sites and be heated that the different heat exchange coefficient carries out accurate controlled differential heating to the latter between the steel plate, utilize the holding force prevention of heated die plate to be heated the distortion of steel plate.
3. one kind according to claim 2 described methods, it is characterized in that said high heat transfer zone is the part of unprocessed mistake on the heated die plate heat-transfer surface, and said low heat transfer zone is the part that reduction is handled through the coefficient of heat transfer on the heated die plate heat-transfer surface.
One kind according to claim 3 described coefficients of heat transfer reduction to handle be that a kind of utilization is created on the method that the lip-deep nick of the low heat transfer zone of heated die plate hole dot matrix reduces its coefficient of heat transfer; Can utilize the method for machinery or chemistry/electrograving to make the pit dot matrix, the size of pit and density can be used for the heat exchanging coefficient and control.
One kind according to claim 3 described coefficients of heat transfer reduction to handle be a kind ofly on low heat transfer zone surface, to make a whole depressed area to cut off heated die plate and direct contact that is heated between the steel plate, the method that makes the coefficient of heat transfer therebetween decided by the radiative transfer between them fully by its profile.
6. one kind according to claim 1 and the described method of claim 2, it is characterized in that having a plurality of shielding gas production wells on the heat-transfer surface of said heated die plate, prevents heated die plate heat-transfer surface and the oxidation that is heated steel plate in order to form localised protection atmosphere.
7. one kind according to claim 1 and the described method of claim 2; It is characterized in that having a plurality of shielding gas production wells on the heat-transfer surface of said heated die plate; In order to when heated die plate unclamps blowing, to produce the shielding gas jet, help to be heated steel plate and break away from heated die plate smoothly.
8. equipment that can carry out fast, not have distortion, non-oxidation even heating or differential heating to tole, by the box-type furnace that plays heat effect with place the heated die plate in it to constitute, it is characterized in that:
A) top of above-mentioned body of heater has an opening for feed, and the bottom has a discharge port;
B) be heated steel plate and put between the heated die plate, emitted from above-mentioned discharge port behind completion location, clamping and the heating schedule by above-mentioned opening for feed;
C) heated die plate possesses characteristic and the function of Accessory Right requirement 1 to the said method of claim 7;
D) heated die plate is passed through lower link and the bottom of following hinge support at the body of heater outside framework;
E) heated die plate be connected with the oil cylinder that is fixed on body of heater outside framework top through last connecting rod and upper hinge also can under the latter's driving, accomplish connect material, clamping and the operation of blowing supervisor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102547594A CN102373325A (en) | 2010-08-17 | 2010-08-17 | Method and device for carrying out uniform heating or differential heating on sheet steel in rapid non-deformation non-oxidation mode |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010102547594A CN102373325A (en) | 2010-08-17 | 2010-08-17 | Method and device for carrying out uniform heating or differential heating on sheet steel in rapid non-deformation non-oxidation mode |
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| CN102373325A true CN102373325A (en) | 2012-03-14 |
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| CN2010102547594A Pending CN102373325A (en) | 2010-08-17 | 2010-08-17 | Method and device for carrying out uniform heating or differential heating on sheet steel in rapid non-deformation non-oxidation mode |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103045834A (en) * | 2013-01-11 | 2013-04-17 | 武汉理工大学 | Method for improving comprehensive properties of high-strength steel plate hot stamping part |
| CN109580462A (en) * | 2018-11-16 | 2019-04-05 | 国网天津市电力公司电力科学研究院 | A kind of suspension type insulating materials thermal aging test fixture |
| CN112126757A (en) * | 2019-06-24 | 2020-12-25 | 宝山钢铁股份有限公司 | Thick-direction variable-strength hardness cold-rolled strip steel and manufacturing method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109580462A (en) * | 2018-11-16 | 2019-04-05 | 国网天津市电力公司电力科学研究院 | A kind of suspension type insulating materials thermal aging test fixture |
| CN112126757A (en) * | 2019-06-24 | 2020-12-25 | 宝山钢铁股份有限公司 | Thick-direction variable-strength hardness cold-rolled strip steel and manufacturing method thereof |
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