MX2008002077A - System and method of computing the oerating parameters of a forge welding machine - Google Patents

Abstract

A system and method for computing the parameters of a forge welding machine for the forge welding of one or more materials is provided. A computer program executes a self-tuning routine to compute the operating frequency and operating power setting for the forge welding machine in response to an inputted width of the heat affected zone and an inputted weld temperature.

Description

SYSTEM AND METHOD FOR COMPUTING THE OPERATING PARAMETERS OF A FORGING MACHINE FIELD OF THE INVENTION The present invention relates generally to forging processes and in particular to the control of the parameters of a forging welding machine in response to an introduced width of the area affected by the heat and the welding temperature of the welding process by forging.

BACKGROUND OF THE INVENTION Forging welding includes joining metal parts, such as plates. For example, Figure 1 (a) illustrates a typical forged weld 101 with a partial T-shaped joint that is made between an edge of the plate 103 and the surface of the plate 105, Figure 1 (b) illustrates a typical weld by partial forge 107 of square stop which is made between opposite ends of plates 109 and 111. Forging welding also includes the joining of edge portions of a sheet or a folded metal strip, wherein the edge portions are forcibly joined at a welding point as the strip is advanced longitudinally in the direction of the formed weld seam. For example, in Figure 2 tube 113 is formed from a strip of metal that is strongly joined at a soldering point 115 to form a welded seam 117 as the strip advances in the direction indicated by the arrow of a tip, and a pressing force is applied in the directions indicated by the arrows of two ends to force the edge portions of the strip to join. In a forging process, a high pressure is supplied at the welding point, which is heated up to the welding temperature, to produce the weld. Generally the welding temperature is lower, but possibly close to the melting point of the metal being welded. The heating of the metal up to the welding temperature can be achieved by using a suitable energy source, such as a laser beam, an electron beam, an electrical resistance or a high frequency electric induction. A forging process results in the creation of a heat affected zone (HAZ), which is the portion of the metal that did not melt during the welding process, but whose microstructure and mechanical properties were altered by the heat produced in the welding process. The procedure. For example, in Figure 2 the flashing lines 118 indicate the generalized outer boundary of the HAZ on both sides of the weld seam 117. As can be seen more clearly in Fig. 3 (a) and Fig. 3 (b) the width of the HAZ, XE > is equal to the distance between the outer boundary lines 118. Although in practice the outer boundaries of the HAZ may not be uniformly linear throughout the length of the welding, the width of the HAZ can be generally approximated by the linear boundary lines. By minimizing the width of the HAZ, the amount of metal that has properties different from those of an unheated metal part is generally minimized. The preferred or effective width of the HAZ is a complex function of many welding parameters that include, but are not limited to, the welding frequency, the wall thickness of the part, the geometry of the part, the length of welded heating , and the angle and speed of the part at the welding point. A particular application of induction forging welding is the welding of pipes and pipes by high frequency induction, where high pressures are applied for very short periods, but at the temperature of the melting point, two edges of a strip are forced in an oval shape by means of a tube forming machine, before the adjacent edges of the strip reach the soldering point, as illustrated in diagrammatic form in FIG. 2, FIG. 3 (a) and FIG. 3 (b). At this temperature the diffusion rates in the solid phase are very high and a quality bond results in a very short period. Ideally all molten metal should be crushed in the joint plane at the weld seams of the inner or outer diameter, and the joint has no molten or cast metal. In Figure 2 an induction energy can be supplied from a suitable source of beam energy (not shown in the figure) to the induction coil 121 to induce a current in the metal that is around a region in "V" shape that is formed by forcing the edges of the strip to join each other. The induced current flows around the back of the tube and then along the open edges in a "V" shape to the solder point 115 as illustrated by the typical flow line 119 (shown as a dotted line). ) in Figure 2. The length, and, of this "V" shaped region is approximately equal to the distance between the end of the coil that is closest to the welding point and the welding point. Generally since this length is related to a particular forging machine, other definitions of this distance can be used, as long as the defined distance is used consistently for a particular forging machine. Reference can also be made to the length and, as the length of welding heating. Although a solenoid coil is shown in Figure 2, other coil arrangements can be used. The effective width of the HAZ is a complex function of many welding parameters that include, but are not limited to, the welding frequency, the component wall thickness, the component geometry, the length and the welding heating angle , the speed of union of the part, and the material of the part. The following illustrates how these parameters can be applied mathematically. The electric reference depth,?, Or the depth of penetration, which defines the distance from the edge of the metal part at which the induced current decreases approximately exponential to e "1 (0.368) of this value on the surface, when the process is a process of welding by forging by induction, it is You can calculate from equation (1): ? = p fμ where p is the electrical resistivity of the metal part, μ is the relative magnetic permeability of the metal part, / is the frequency of the electric welding of the supplied power, and p is the constant pi (3.14159).

The thermal reference depth, d or the depth of Thermal diffusion, which represents how deeply the edge has been heated by thermal conduction, can be calculated from the equation (2): ^ 4v where e is the thermal diffusivity of the metal part, and it is the profanity of "V", which is also known as the length of welding heating, and v is the speed at which the metal part (strip) passes through the Welding point, which is also known as the welding speed. There is a functional relationship between the reference depth electric and the width of the HAZ when these two quantities are normalized by the proficiency of thermal diffusion.

A standardized electrical reference depth, Zn, is You can calculate from equation (3): "d The standardized width of the HAZ, Xn, can be calculated from from equation (4): Xn = a0 + a] Zn + a2Zn2 + aiZ Equation (4), or the normalized width of the polynomial HAZ, It can be established by welding by experimental forging of specific types of metal materials. For example, each of the data points Empirical Xi to x-is in Figure 4 represents a normalized electrical reference depth (Zn) and corresponds to the standardized width of the HAZ (Xn). Any suitable model can be used to adjust the empirical data collected to a curve. In this particular example a suitable non-linear curve fitting model is used to fit the data points to an equation with the polynomial form of equation (4) as illustrated in diagram form with the polynomial curve pi in figure 4. The polynomial has generally the form Xn = f (Zn) and the coefficients ao, a ^ a2 and aß in the equation (4) represent derived coefficients for a specific material in the experiments or tests that result in the data points empirical The effective welding energy, PE, is calculated with the equation (5): PE = H »?» XE * h * v where H is equal to the enthalpy of the welding process by forging; that is, the change in enthalpy (measured in joules when PE is calculated in watts) of a metal in the forging process where the temperature of the metal rises from its pre-welded temperature to its welding temperature; ? is the density of the metal (measured in kilograms per cubic meters); XE is the effective width of the area affected by the heat (measured in meters); h is the thickness of the metal to be welded (measured in meters); and v is the velocity of the metal that is being welded at the welding point, or the welding speed (measured in meters per second). An object of the present invention is to achieve a forging welding with a forging welding machine by specifying the preferred width of the area affected by the heat for welding and the preferred welding temperature in the forging of one or more materials without the knowledge of the operating frequency required in the forging welding machine or the adjustment of operating energy. Another object of the present invention is to establish the operating frequency and the operational energy setting of the forging machine in a forging process to achieve a desired welding without the operator of the forging machine having to introduce the frequency and power settings.

BRIEF DESCRIPTION OF THE INVENTION In one aspect, the present invention is a system for controlling the parameters of a forging welding machine for the forging of one or more materials. The system comprises a computer, one or more computer memory storage devices and a computer program. The computer program executes a self-tuning routine to compute the operational frequency and operational energy settings for the forging machine in response to an entered width of the zone affected by the heat and at a welding temperature input. In another aspect the present invention is a method for computing the operating frequency and operating energy setting for a forging machine in a forging welding of one or more materials. The method includes entering a width for the zone affected by heat and entering a welding temperature to compute the operating frequency and operational energy setting for the forging welding machine. The data of the forging welding machine, such as the welding speed and the welding heating length, and the parameters of one or more materials, such as thickness, density and enthalpy, are referenced to compute the operating frequency adjustment and of operational energy. The width of the area affected by the heat and the welding temperature can be measured during the welding by forging to adjust the operative frequency or frequency of operative energy computed, so that the measured width of the area affected by the heat and the measured welding temperature are equal to the width entered of the area affected by the heat and the welding temperature entered in any permitted tolerance. Other aspects of the invention are pointed out in this specification and in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the invention, a form that is currently preferred is shown in the drawings; however, it should be understood that this invention is not limited to the precise arrangements and instrumentation shown. In Figure 1 (a) illustrates a typical weld for joint bonding in Partial T and Figure 1 (b) illustrates a typical weld by boot joining forge. Figure 2 illustrates a typical formation of a tube by the joining by forging welding of opposite longitudinal edges of a metal plate or strip. Figure 3 (a) further illustrates parameters associated with the forging welding of opposite longitudinal edges of a metal plate or strip to form a tube.

Figure 3 (b) is a cross-sectional view through the line A-A in Figure 3 (a) with the illustration of parameters of a tube formed in a forging welding. Figure 4 is a typical graphical illustration of a standardized nominal poly HAZ width generated from empirical data points. Figure 5 illustrates a typical temperature distribution curve that is used to calculate the width of the HAZ. Fig. 6 (a) and Fig. 6 (b) are a flow diagram illustrating a method for determining the adjustment of operating frequency and operating energy for a forging machine in a forging process based on in the entered width of the HAZ and the welding temperature.

DETAILED DESCRIPTION OF THE INVENTION In figures 6 (a) and FIG. 6 (b) a non-limiting example of the system and the method for computing the operating parameters of a forging welding machine of the present invention is illustrated. Although the system and the method relate to the forging by induction of the longitudinal edges of a strip or a metal plate, with appropriate modifications, one skilled in the art can apply the system or the method to any process of welding by forging in which a HAZ is created. The Routines in the figures may be represented in a computer program code that is prepared by a person skilled in the art and is executed with a suitable computer hardware, including, but not limited to, processors, memory storage devices and devices. introduction and exit. The term "metal" is used to simply describe the part or parts of material that will be joined by forging, including, but not limited to strips and metal plates. The term "forging welding" or "forging welding machine" is used to simply or generally describe the machinery that is used for metal forging, including, but not limited to, a forming machine. The term "forging welding power source" is used to simply or generally describe the source of energy that heats the metal for forging, including, but not limited to, an electrical induction power source. In routine 12, the material parameters of the metal are introduced by any suitable means. For example, the operator of a forging machine can enter a value for each parameter by means of a suitable input device, such as a keyboard, or the operator can enter a code that represents a specific material for which the values of the parameters required in a suitable memory device, said data are referenced by the system or method of the present invention. The material parameters can include the thickness (h) of the metal; the electrical resistivity (p) of the metal; the relative magnetic permeability (μ) of metal; the thermal diffusivity (e) of the metal; the enthalpy (H) of the metal, and the density (?) of the metal. In routine 14 welding parameters are introduced by forging by any suitable means. For example, the operator of a forging machine can enter a value for each parameter by means of a suitable input device, or values can be entered for one or more parameters from a reference table of the values stored in a suitable memory device. . The stored values can be based on the material parameters and / or the entered operating parameters of a specific forging welder, said data being referenced by the system or method of the present invention. The parameters of the forging welding machine can include the length of welding heating and the welding speed. In routine 16 welding parameters are introduced by forging by any suitable means. For example the forge welder operator can enter each parameter by any suitable input device, or one or more of the parameters can be entered from a stock reference table stored in a suitable memory device, based on material parameters entered and / or operating parameters of a specific welding machine. The welding parameters entered can include an effective width of the HAZ (XE) and the temperature of the welding point (TE).

In the routine 18 a thermal test reference depth can be computed from the above equation (2) in this non-limiting example of the invention. In routine 20, an electric welding frequency of test, F0, is introduced. For example if the forging welder with which the procedure is being used has an energy operating frequency scale of 10 kilohertz to 100 kilohertz, the initial test frequency may be present and stored in a suitable memory device such as 10 kilohertz, and introduced from the memory device. Alternatively, the operator of the forging welding machine can manually enter the initial test frequency through a suitable input device. In any case as the operating frequency for the selected effective width of the HAZ, XE can be determined by an iterative procedure as will be described below, the selection of a particular initial test frequency is not critical. In the routine 22 an electrical reference reference depth can be computed from the above equation (1) for this non-limiting example of the invention. In routine 24 a standardized electrical referenced test depth Zn is calculated from the above equation (3) in this non-limiting example of the invention. This value of the normalized reference electric test depth is entered into the routine 26, which computes a corresponding standardized test width of the HAZ, Xn from the normalized width of the above equation (4) of HAZ in this non-limiting example of the invention. In routine 28 the standard test width of HAZ, Xn becomes a calculated width of the HAZ, Xc, multiplying Xn by the thermal reference test depth, which was computed in routine 18. In routine 30 the width calculated from the HAZ is compared to the previously entered effective width of the XE. If Xc is not equal to XE within an allowable tolerance, the test frequency, F0, changes to a new value in routine 32. For example, yes Xc > XE +? E, where? E is a tolerance value allowed, then the new test value of F0 will be the old test value of F0 plus an initial incremental frequency change,? F. On the contrary, if Xc < XE-? E, then the new test value of F0 will be the old test value of F0 minus a selected initial incremental frequency change,? F. In the following repetitions, the incremental frequency change,? F, decreases, for example, by half, so that the iterative procedure finally results in a calculated Xc = XE + e, where e is a value of tolerance allowed, if used, for a desired effective width of the HAZ. The test value of F0 for which Xc = XE + e is set equal to the set frequency, FSEt, in routine 34. Any alternative type of iterative method suitable to converge on the set frequency can be used.

In some examples of the invention, the system and method for computing the operating parameters of a forging welding machine can include computing the operating frequency of the forging welding machine. In other examples of the invention, the system and method further include computing the operational energy setting of the forging welding machine. When Xc = XE ± e is established at the set frequency, FSE ?, in routine 34, the effective energy, PE can be computed from the above equation (5) in this non-limiting example of the invention in routine 36 , and the value of the effective energy can be adjusted equal to the established operating energy, PSEt- The routine 38 executes a test forging welding at an operating frequency FsEt and an operating energy FsEt. The true measured width of the HAZ, XTEST. from the test run is entered into the routine 40 by any suitable detection method, as a thermal imaging camera. The analysis of thermal images can produce a graphic display of the magnitude of temperature against the cross-sectional width of the metal. For example in Figure 5, the maximum temperature, Tmax, occurs at the welding point and comes out at the welding point in a curve having a general bell shape. A XTEST can be assigned a typical value, for example, 0.5Tm ?, as can be seen in the figure. Alternatively the HAZ width can be determined from metallurgical samples cut from a welded tube. The shape of the temperature curve in Figure 5 and the selection of 0.5Tma? as the point of temperature for a limit of the width of the HAZ, is a non-limiting selection. For a forging machine and a specific forging process, other temperature and temperature curves can be applied in the width limit of the HAZ. This means that the temperature curve and the boundary temperature are related to the forging process. The routine 42 compares the test run width of the HAZ, XTEST, with the effective width entered of the HAZ, XE. If XTEST is not equal to XE in any permissible tolerance, the width of the curve empirically adjusted by HAZ changes in routine 44, where the point defined by Zn and Xn, which results from the established frequency, FSEt, and energy established PSEt, and used in the test run, is added to the set of points that are used to generate the established curve, and a new curve fitting analysis is carried out. Routines 26 to 42 are repeated iteratively until the test run width of the HAZ, XtEst, is equal to the entered width of the HAZ, XE, within any allowable tolerance. Then routine 43 continues with the test run and the temperature of the true test solder point TMA ?, is compared to the effective soldering point temperature introduced, TE, in routine 48. The true solder point temperature of Test is entered into routine 46 using a suitable sensor, such as a pyrometer. If the TMA? is not equal to the effective soldering point temperature, TE, within an allowable tolerance the enthalpy value (H) for the material is changed to a new value in routine 50 and a new value is calculated value for the effective energy, PE, in routine 36. For example if TMA ?, > TE +? E, where? E is a tolerance value allowed, then the new enthalpy value (H) would be the old value minus a selected incremental change,? H. On the contrary if TMA ?, > TE-? E, then the new enthalpy value (H) would be the old enthalpy value (H) plus a selected incremental change,? H. In subsequent iterations, the incremental change in enthalpy? H, decreases, for example by half, such that the iterative procedure ultimately results in a TMAx, > E +? calculated, where e is a tolerance value allowed, if used, for a desired effective width of the HAZ. Routines 36 to 48 are executed repeatedly until MA, > E ±? E, where e is a tolerance value allowed for the temperature of the desired effective soldering point. When this condition is satisfied, the routine 52 establishes a production run at the operating frequency of the forging welder, FsEt, and the operating energy, PsEt- The US patent. No. 5,902,506 and No. 5,954,985 describe apparatuses and methods for adjusting the frequency and magnitude of energy of an induction forging iron power source that can be used in the method of the present invention. Therefore, in a system example and method for computing the operating parameters of a forging welding machine of the present invention, a computer program can be used to compute the operating frequency and operating energy setting for the machine. for welding by forging in response to an inserted width of the area affected by heat and a welding temperature introduced. The computation can be based on the data of the forging welding machine and on the parameter data of one or more materials that will be welded in the forging process. The above examples of the invention illustrate some welding machine data by forging and non-limiting parameter data of one or more materials that can be used in the system or method of the present invention. The above examples do not limit the scope of the invention described. The scope of the invention described is further indicated in the following claims.

Claims (19)

NOVELTY OF THE INVENTION CLAIMS

1. - A system for controlling the parameters of a forging welding machine for the forging of one or more materials, the system comprises a computer, one or more computer memory storage devices and a computer program, the program of The computer performs a self-tuning procedure to compute the operational frequency and operating energy setting for the forging machine in response to an entered width of the area affected by the heat and the welding temperature input.

2. The system according to claim 1, further characterized in that one or more memory storage devices store data from the welding machine by forging and data for the parameters of one or more materials.

3. The system according to claim 2, further characterized in that the data of the forging welding machine comprise the welding speed and the length of welding heating, and the data for the parameters of one or more materials comprise the thickness, density and enthalpy of one or more materials.

4. The system according to claims 1, 2 or 3, further characterized by the auto tuning procedure it includes data entered for a measured width of the area affected by the heat and the welding temperature measured for the forging.

5.- A method to compute the adjustment of operating frequency and the operative energy for a welding machine by forging, in the welding by forging of one or more materials, the method comprises the steps of introducing a width of the area affected by the heat, enter a welding temperature and compute the operating frequency and operating energy setting for the forging machine.

6. The method according to claim 5, further characterized in that it further comprises the steps of referencing the data of the welding machine by forging and referencing the parameters of the one or more materials.

7. The method according to claim 5 or 6, further characterized in that it additionally comprises the steps of referencing data for the welding speed, the length of welding heating, the thickness of one or more materials, the density of the one or more more materials and the enthalpy of one or more materials.

8. The method according to claim 5, 6 or 7, further characterized by additionally comprising the steps of measuring the width of the area affected by heat for welding by forging, measuring the welding temperature for welding by forging and adjust the computed adjustment of the operating frequency or operating energy in response to the measured width of the area affected by the heat and the measured welding temperature in comparison with the entered width of the area affected by the heat and the welding temperature introduced.

9. A method to compute the operating frequency for a welding machine for forging in a forge welding, the method comprises the steps of: (a) entering the parameters of one or more materials that will be welded by forging; (b) enter the parameters of the welding machine by forging; (c) enter the preferred width of the area affected by the heat; (d) compute the test thermal reference depth; (e) enter an operational test frequency; (f) compute an electric test reference depth; (g) compute a standardized electric reference test depth; (h) compute a normalized test width of the area affected by heat from a parametric equation; (i) converting the normalized test width of the affected area by heat to a calculated width of the area affected by the heat; and (j) comparing the calculated width of the area affected by the heat with the preferred width of the area affected by the heat, and if the calculated width of the area affected by the heat is equal within an allowable tolerance to the preferred width of the zone. the area affected by the heat, adjust the operating frequency of the welding machine by forging with the test operating frequency, or otherwise change the test frequency and perform steps (3) to (j).

10. The method according to claim 9, further characterized in that the material parameters of the one or more materials comprise thermal diffusivity, electrical resistivity and relative magnetic permeability of the one or more materials, and the parameters of the forging welding machine comprise the length of welding heating and the welding speed.

11. The method according to claim 10, further characterized in that the parametric equation comprises a polynomial in the form of the normalized width of the area affected by heat as a function of the normalized electrical reference depth.

12. The method according to claim 9, 10 or 11, further characterized by additionally comprising the steps of: (k) computing an effective test energy; (I) operating the forging welding machine in a test run at the operating frequency and the effective test energy; (m) measure the width of the test of the area affected by the heat from the test run; (n) enter the test width of the area affected by the heat; (o) comparing the test width of the heat-affected area with the preferred width of the area affected by the heat, and if the test width of the heat-affected zone is equal within an allowable tolerance to the preferred width from the zone by heat, adjusting the operating energy of the welding machine by forging to the effective test energy, or otherwise generating a modified parametric equation and iteratively performing steps (h) to (o); (p) operating the forging welding machine in a welding temperature test run at the operating frequency and the operating energy; (q) entering a preferred welding temperature; and (r) measuring a test run welding temperature during the run of Welding temperature test, and if the welding temperature of the test run is equal within an allowable tolerance to the preferred test run temperature then do a production run of the forging welder at operating frequency and operating energy , or otherwise change the enthalpy of one or more materials and iteratively perform steps (k) to (r).

13. The method according to claim 12, further characterized in that the material parameters comprise the thermal diffusivity, electrical resistivity, relative magnetic permeability, thickness and enthalpy of the one or more materials and the parameters of the forging welding machine comprise the length of welding heating and the welding speed.

14. The method according to claim 12 or 13, further characterized in that the parametric equation comprises a polynomial in the form of the normalized width of the area affected by the heat as a function of the normalized electrical reference depth.

15. The method according to claim 12, 13 or 14, further characterized in that the modified parametric equation is generated by adding a point defined by the normalized electrical reference depth of test and the normalized test width of the area affected by the test. heat to adjust the empirical points that are used to generate the parametric equation from a curve fitting model.

16. - A method to compute the operating frequency for a forging machine in a forging welding, the method comprises the steps of: (a) entering the material parameters of one or more materials that will be welded by forging; (b) enter the parameters of welding by forging; (c) enter a preferred width of the area affected by the heat; (d) compute the assay reference depth; introduce an operational test frequency; (f) compute an electric test reference depth; (g) compute a standardized electric reference test depth; (h) compute a normalized width of the zone affected by heat from a parametric equation; (i) converting the normalized test width of the affected area by heat to a calculated width of the area affected by the heat; (j) comparing the calculated width of the area affected by the heat with the preferred width of the area affected by the heat, and if the calculated width of the area affected by the heat is equal within an allowable tolerance to the preferred width of the zone affected by heat, setting the operating frequency of the welding machine by forging at the test operating frequency, or otherwise changing the test frequency and performing steps (e) to (j); (k) compute the effective test energy; (I) operating the forging welding machine in a test run at the operating frequency and the effective test energy; (m) measuring the test width of the area affected by heat from the test run; (n) enter the test width of the area affected by the heat; (o) compare the test width of the area affected by the heat with the preferred width of the area affected by heat and if the test width of the area affected by heat is equal within a permissible tolerance to the preferred width of the area affected by heat, adjust the operational energy of the welding machine by forging to energy effective test, or otherwise generate a modified parametric equation and iteratively perform steps (h) or (o); (p) operating the forging welding machine in a welding temperature test run at the operating frequency and the operating energy; (q) entering the preferred welding temperature; and (r) measuring the welding temperature of the test run during the test run of the welding temperature, and if the welding temperature of the test run is equal within an allowable tolerance to the running temperature of the test run. preferred test, then perform a production run of the forging welder at the operating frequency and operating energy, or otherwise change the enthalpy of one or more materials and iteratively perform steps (k) to (r).

17. The method according to claim 16, further characterized in that the parameters of the material comprise the thermal diffusivity, electrical resistivity, relative magnetic permeability, thickness and enthalpy of the one or more materials and the parameters of the forging welding machine comprise the length of the welding heating and the welding speed.

18. The method according to claim 16 or 17, further characterized in that the parametric equation comprises a polynomial in the form of the normalized width of the area affected by the heat as a function of the normalized electrical reference depth.

19. The method according to claim 16, 17 or 18, further characterized in that the modified parametric equation is generated by adding a point defined by the normalized electric reference depth of the test and the normalized test width of the area affected by the test. heat to adjust the empirical points that are used to generate the parametric equation from the curve fitting model.