Welding repair method for dissimilar copper material of drawing die

Abstract

The invention provides a welding repair method for a dissimilar copper material of a drawing die, and relates to the technical field of automobile part manufacturing. The method comprises the following steps that argon configuration parameters, welding parameters and welding material types of argon arc welding are set; the welding material types comprise three different copper welding wires; a welding groove is prepared according to the abrasion area of the drawing die; preheating the welding groove according to the preset welding temperature and the preheating area; a preset deposition scheme is adopted, and deposition welding is conducted on the welding groove; wherein the height difference between the welded welding surface and the end face of the welding groove is larger than or equal to the first allowance; and after cooling to room temperature, carrying out molded surface correction on the welding surface by taking the outer surface of the drawing die as a reference surface. Compared with the prior art, the problem of adhesive abrasion caused by mutual friction between the same materials can be eliminated, the galling defect between the two materials can be reduced, and therefore the problem of surface abrasion of the drawing die is solved.

Description

Technical Field

[0001] The present application relates to the technical field of a dissimilar copper material welding process, and in particular to a method for welding and repairing dissimilar copper materials of a drawing die. Background Art

[0002] At present, the drawing die for large automobile panels is the most important process to ensure the molding quality, surface quality, production efficiency and production cost of the parts. In daily use, the drawing die will be affected by the extrusion and friction of the sheet metal, causing adhesion and roughening damage to the complex forming parts such as the pressing surface and the rounded corners of the punch, resulting in various quality defects such as roughening and cracking of the parts. Due to the friction between the mold material and the processed sheet metal, the problem of adhesion and roughening cannot be fundamentally eliminated. Therefore, maintenance fitters need to frequently grind and polish the mold in production to ensure the quality of the parts and the working stability of the mold. However, such long-term grinding and polishing will damage the working surface of the mold, reduce the precision of the stamping parts, and also cause the mold to wear and fail prematurely, reducing the life of the mold.

[0003] At present, the methods for preventing adhesion and roughening problems and repairing mold roughening and damage in the industry mainly include mold surface chrome plating, surface welding repair process, and pressing surface replacement technology.

[0004] 1. Surface chrome plating: The chrome plating process is mainly a preventive process to reduce the friction coefficient between the mold surface and the sheet material, and to improve the mold's resistance to roughening and wear. However, the chrome plating process is costly and has a short lifespan. In some parts with complex molding, the chrome layer will wear and fall off prematurely under the action of the deformation force and friction of the parts, causing roughening and wear on both surfaces. Although repeated chrome plating can reduce the roughening problem, due to cost issues, companies will not choose to repeat chrome plating within a certain period of time, and can only maintain production by continuous polishing and grinding during production.

[0005] 2. Welding repair process: At present, when the mold is damaged, TIG (Tiger Inert Gas) arc welding is mainly used, and the damaged part is repaired by fusion welding using welding materials that are the same or similar to the mold base material. However, this type of iron-based welding material and the processing material belong to the same type of metal friction pair. In the actual production process, the two materials will also have adhesion and roughening damage during relative sliding friction.

[0006] 3. Pressing surface replacement technology: In accordance with the basic principle of reducing adhesive wear, the pressing surface of the deep drawing die is machined out as a whole and replaced with a detachable beryllium copper insert structure. Because beryllium copper materials and processed sheets will not have adhesion problems, the problem of adhesive roughening can be eliminated. However, when adhesion roughening appears on the die surface in the early stage, it is mostly point-shaped, line-shaped or localized small-area damage. If the insert structure is replaced as a whole, it will undoubtedly greatly increase the company's maintenance costs. Therefore, this technology is rarely used in actual maintenance processes.

[0007] Since the existing mold materials, prevention processes, and maintenance technologies are unable to eliminate the problem of adhesive burrs and breakage at low cost and high quality, the molds are repeatedly re-welded, ground, and polished during the production and maintenance process, causing the main molding parts of the molds to wear out prematurely or even fail, which not only reduces the service life of the molds, but also increases the company's maintenance and production costs.

[0008] Based on the above content, a method for welding and repairing dissimilar copper materials of a drawing die is urgently needed to solve the above technical problems. Summary of the invention

[0009] The purpose of this application is to provide a method for welding and repairing dissimilar copper materials of a drawing die, replacing the original roughened and damaged part with a copper-based working surface to solve the problem of surface wear of the drawing die. The specific scheme is as follows:

[0010] A method for welding and repairing dissimilar copper materials of a drawing die comprises the following steps:

[0011] Step 1: Setting the argon gas configuration parameters, welding parameters and welding material types of argon arc welding; the welding material types include three copper welding wires of different materials;

[0012] Step 2: Prepare the welding groove according to the wear area of ​​the drawing die;

[0013] Step 3: Preheat the welding groove according to the preset welding temperature and preheating area;

[0014] Step 4: using a preset deposition scheme to perform deposition welding on the welding groove; wherein the height difference between the welding surface after welding and the end surface of the welding groove is greater than or equal to the first margin;

[0015] Step 5: After cooling to room temperature, use the outer surface of the drawing die as the reference plane to correct the welding surface.

[0016] In a specific embodiment, the argon gas configuration parameters include: DC positive electrode welding, argon gas purity ≥ 99.8%, gas flow rate 25-30 L / min;

[0017] Welding parameters include: using a cerium tungsten electrode with a preset diameter, the grinding angle of the cerium tungsten electrode tip is ≤30°, the length of the cerium tungsten electrode extending out of the porcelain nozzle is ≤5mm, and the nozzle uses a porcelain nozzle with a preset caliber;

[0018] The types of welding materials include three copper welding wires of different materials, wherein the three copper welding wires are respectively a copper alloy welding wire with a hardness of 35-45HB, a brass alloy welding wire with a hardness of 80-85HB, and an aluminum bronze alloy welding wire with a hardness of 130-140HB; wherein the diameters of the copper alloy welding wire, the brass alloy welding wire and the aluminum bronze alloy welding wire are the same.

[0019] In a specific embodiment, the step 2 specifically includes:

[0020] Step 201: grinding and removing the worn surface of the drawing die;

[0021] Step 202: Prepare a U-shaped welding groove; wherein the opening area of ​​the welding groove is larger than the wear area of ​​the drawing die, and the upper edge of the welding groove does not adopt a blunt chamfer design.

[0022] In a specific embodiment, the preset welding temperature is 350-500° C., and the preheating area includes the welding groove area and the area extending to the circumference by a preset distance with the opening edge of the welding groove as the boundary;

[0023] After step 3, the method further includes: a cleaning step of the inner surface of the welding groove.

[0024] In a specific embodiment, the preset welding scheme in step 4 specifically includes:

[0025] Based on the depth and the first margin of the welding groove, a welding operation is performed on the welding groove according to a preset weld deposition layer ratio and a preset welding sequence;

[0026] During welding, adjust the welding current according to the type of welding materials, welding sequence, and welding location.

[0027] In a specific embodiment, the welding operation is performed on the welding groove based on the depth of the welding groove and the first margin according to a preset weld deposition layer ratio, specifically including:

[0028] Use copper alloy with hardness of 35-45HB as the base layer of welding groove;

[0029] Use brass alloy with hardness of 80-85HB as the transition intermediate layer of the welding groove;

[0030] Aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove.

[0031] In a specific embodiment, a copper alloy with a hardness of 35-45 HB is used as a base layer of the welding groove, specifically comprising:

[0032] The copper alloy welding wire is used to sequentially complete the deposition welding operation of the top of the side wall of the welding groove, the bottom of the welding groove, and the side wall of the welding groove; wherein the welding current of the copper alloy welding wire is 60-90A;

[0033] Furthermore, a brass alloy with a hardness of 80-85HB is used as a transition intermediate layer of the welding groove, specifically including:

[0034] The transition intermediate layer of the welding groove is welded by using a brass alloy welding wire; the welding current of the brass alloy welding wire is 70-80A;

[0035] Furthermore, an aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove, specifically including:

[0036] Aluminum bronze alloy welding wire is used to perform deposition welding on the outer layer of the welding groove; the welding current of the aluminum bronze alloy welding wire is 110-120A.

[0037] In a specific embodiment, during the welding process of the copper alloy welding wire, a pre-stacking method is used to weld the top of the side wall of the welding groove.

[0038] In a specific embodiment, during the deposition welding process, the wire filling speed is adjusted based on the molten droplet state of the welding wire.

[0039] In a specific embodiment, it also includes:

[0040] During the deposition welding process, the length of each weld bead is less than the first length value, and the welding start temperature of each weld bead is 150-200° C.;

[0041] After each weld is completed, the weld is hammered using the reverse hammering method.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention provides a method for welding and repairing dissimilar copper materials of a drawing die. By surfacing, three copper-based alloy welding materials with different properties are used in a base, transition and cover manner to replace the original roughened and damaged part of the drawing die with a copper-based working surface, so as to change the friction properties between the die and the processed material, eliminate the adhesive wear problem caused by mutual friction between the same materials, and reduce the roughening defect problem between the two materials, thereby solving the surface wear problem of the drawing die. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the process of welding and repairing the dissimilar copper materials of the drawing die;

[0045] Figure 2 It is a schematic diagram of the cross-sectional structure of the welding groove on the drawing die;

[0046] Figure 3 It is a top view toward the welding groove;

[0047] Figure 4 The schematic diagram of the deposition welding sequence of the welding groove is shown in FIG.

[0048] Figure 5 It is the schematic diagram of anti-wear test;

[0049] Figure 6 This is a schematic diagram of the rough wear of the drawing die;

[0050] Figure 7 It is a schematic diagram of a U-shaped welding groove;

[0051] Figure 8 This is a schematic diagram of the pre-stacking and base layer of copper alloy;

[0052] Fig. 9 It is a schematic diagram of the brass alloy deposited transition intermediate layer;

[0053] Fig.10 This is a schematic diagram of the aluminum bronze cover surface;

[0054] Fig.11 Schematic diagram of the end face of the drawing die after profile correction. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of this application clearer, the following will be combined with the attached Figure 1-11 The present application is further described in detail. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0056] It should be understood that although the terms first, second, third, etc. may be used to describe in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

[0057] In the figure: 100, drawing die; 200, welding groove.

[0058] A method for welding and repairing dissimilar copper materials of a drawing die comprises the following steps:

[0059] Step 1: Setting the argon gas configuration parameters, welding parameters and welding material types of argon arc welding; the welding material types include three copper welding wires of different materials;

[0060] Step 2: Prepare the welding groove according to the wear area of ​​the drawing die;

[0061] Step 3: Preheat the welding groove according to the preset welding temperature and preheating area;

[0062] Step 4: using a preset deposition scheme to perform deposition welding on the welding groove; wherein the height difference between the welding surface after welding and the end surface of the welding groove is greater than or equal to the first margin;

[0063] Step 5: After cooling to room temperature, use the outer surface of the drawing die as the reference plane to correct the welding surface.

[0064] Specifically, the present application uses a surfacing method to replace the original roughened and damaged parts with a copper-based working surface by priming, transitioning, and covering three copper-based alloy welding materials with different properties, so as to change the friction properties between the mold and the processed material, eliminate the adhesive wear problem caused by mutual friction between the same materials, and reduce the roughening defect problem between the two materials, so as to solve the surface wear problem of the drawing die; this method makes the fusion strength of dissimilar copper materials good, the hardness high, and at the same time have certain impact resistance and wear resistance.

[0065] Furthermore, the present application can quickly complete point, line and surface replacement welding repairs according to the damaged position on the drawing die surface, which can maintain the consistency and integrity of the original structure of the die body to the maximum extent. It has low cost, high quality, simple operation and wide application. It can also implement material replacement on multiple important forming parts such as the pressing surface, drawing ribs, punch radius, and punch and die of the flanging process of the drawing die to eliminate adhesive roughening defects.

[0066] It can be understood that the welding repair method for dissimilar copper materials of a drawing die provided in the present application can improve the surface quality and molding quality of the parts while improving the production stability of the mold, reducing production maintenance time, improving production efficiency and reducing production costs.

[0067] Furthermore, the present application can extend the mold surface strengthening treatment cycle, extend the mold maintenance cycle, reduce maintenance costs, and extend the mold service life.

[0068] In this embodiment, the argon gas configuration parameters include: argon arc welding adopts direct current positive electrode welding, the purity of argon gas is ≥99.8%, and the gas flow rate is 25-30L / min;

[0069] The welding parameters include: using a cerium tungsten electrode with a preset diameter (e.g., a cerium tungsten electrode with a diameter of Φ2.4mm), the grinding angle of the cerium tungsten electrode tip is ≤30°, the length of the cerium tungsten electrode extending out of the porcelain nozzle is ≤5mm, and the nozzle uses a porcelain nozzle with a diameter of 11mm;

[0070] The types of welding materials include three copper welding wires of different materials, wherein the three copper welding wires are respectively a copper alloy welding wire with a hardness of 35-45HB, a brass alloy welding wire with a hardness of 80-85HB, and an aluminum bronze alloy welding wire with a hardness of 130-140HB; wherein the diameters of the copper alloy welding wire, the brass alloy welding wire and the aluminum bronze alloy welding wire are the same, all being 2.0mm.

[0071] It should be noted that, since the traditional cast iron welding materials are consistent with the cast iron base material of the mold body, the working accuracy of the mold can be restored. However, in actual production and use, the adhesion and roughening problem between the mold and parts has not been solved, that is, the roughening problem cannot be solved when the basic friction conditions of the repair welding area are not changed. The density of copper material is higher than that of cast iron, and it also has excellent polishing performance and anti-adhesion properties. Therefore, the original mold roughening damaged parts are replaced with copper material by welding to solve the adhesion and roughening problem.

[0072] The step 2 specifically includes:

[0073] Step 201: grinding and removing the worn surface of the drawing die;

[0074] Step 202: Prepare a U-shaped welding groove; wherein the opening area of ​​the welding groove is larger than the wear area of ​​the drawing die, and the upper edge of the welding groove does not adopt a blunt chamfer design.

[0075] It can be understood that in this embodiment, a mechanical method can be used, such as using an angle grinder to grind and remove the roughened and damaged surface or fatigue surface of the drawing die, and to grind out a U-shaped welding groove; wherein the depth of the welding groove is capable of depositing at least three welding materials;

[0076] In this embodiment, a detailed description is given by taking the welding groove depth of 8 mm as an example.

[0077] It should be noted that when the dissimilar copper welding materials and the cast iron material of the mold body are fused and welded, the solubility of iron in copper is quite small, and iron exists in the form of free iron, which makes it impossible for iron and copper to form a continuous solid solution, that is, the bonding strength of the two parent material matrices is not high. Therefore, the welding groove depth must be able to at least meet the requirements of the deposition of three welding materials, and the welding groove does not have a blunt chamfer to ensure the bonding strength of the two materials. The copper-based material is more often placed on the mold surface in an inlaid form.

[0078] The preset welding temperature in step 3 is 350-500° C., and the preheating area includes the welding groove area and the area extending to the circumference by a preset distance (eg, 10 mm) with the opening edge of the welding groove as the boundary.

[0079] Specifically, the welding temperature is preset to 350-500℃, and the drawing die welding groove is preheated before welding, which is a crucial operation step when welding dissimilar materials. Due to the large difference in thermal conductivity and expansion coefficient between the drawing die and the welding wire, the shrinkage rate and shrinkage time after welding are different, which will generate a lot of welding stress and cause deformation or cracks. Preheating before welding can reduce the shrinkage time difference of different materials and slow down welding stress deformation; at the same time, the oil and moisture contained in the mold body can be baked out during preheating.

[0080] Secondly, the preheating temperature is selected to be 350-500℃, which is 200-300℃ higher than the traditional preheating temperature. Through high-temperature preheating, the gas generated by the heating of various alloy materials of the mold body is released, avoiding the generation of pores or nests in the later welding process and reducing the welding quality.

[0081] After step 3, the method further includes: cleaning the inner surface of the welding groove; specifically, cleaning the debris with a wire brush after preheating and baking, thereby cleaning various impurities, carbides or colloids on the surface of the welding groove to prevent slag inclusions from forming during welding.

[0082] The preset deposition scheme in step 4 specifically includes:

[0083] Based on the depth and the first margin of the welding groove, a welding operation is performed on the welding groove according to a preset weld deposition layer ratio and a preset welding sequence;

[0084] During welding, adjust the welding current according to the type of welding materials, welding sequence, and welding location.

[0085] The step of performing welding operation on the welding groove based on the depth of the welding groove and the first margin and according to a preset weld deposition layer ratio specifically includes:

[0086] Use copper alloy with hardness of 35-45HB as the base layer of welding groove;

[0087] Use brass alloy with hardness of 80-85HB as the transition intermediate layer of the welding groove;

[0088] Aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove.

[0089] In this embodiment, the preset weld deposited layer ratio is: number of copper alloy weld deposited layers: number of brass alloy weld deposited layers: number of aluminum bronze alloy layers = 1:2:2; wherein the thickness of the single-layer weld deposited layer of the copper alloy, the brass alloy and the aluminum bronze alloy is 2 mm.

[0090] Furthermore, a copper alloy with a hardness of 35-45HB is used as a base layer for the welding groove, specifically including:

[0091] Combination Figure 3 As shown, copper alloy welding wire is used to sequentially complete the deposition welding operation of the top of the side wall of the welding groove, the bottom of the welding groove, and the side wall of the welding groove; wherein the welding current of the copper alloy welding wire is 60-90A;

[0092] The base layer is welded by weld beads A, B, and C; the top welding part of the side wall corresponds to weld bead A, the bottom welding part of the groove corresponds to weld bead B, and the side wall welding part corresponds to weld bead C;

[0093] Furthermore, a brass alloy with a hardness of 80-85HB is used as a transition intermediate layer of the welding groove, specifically including:

[0094] The transition intermediate layer welded by welding bead D is welded by brass alloy welding wire; the welding current of the brass alloy welding wire is 70-80A;

[0095] Furthermore, an aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove, specifically including:

[0096] The outer layer welded by weld bead E is welded by aluminum bronze alloy welding wire; the welding current of the aluminum bronze alloy welding wire is 110-120A.

[0097] In this embodiment, first, a copper alloy welding wire is used to lay a base layer, and a layer is deposited with a deposition height of 2 mm;

[0098] Then, brass alloy welding wire is used as the transition intermediate layer, and two layers are deposited with a deposition height of 4 mm.

[0099] Finally, aluminum bronze alloy welding wire is used to cover the surface. High-hardness welding materials can improve the hardness and wear resistance of the working surface. Two layers are deposited with a deposition height of about 4 mm. The welding current is adjusted to 110-120A, covering the entire welding groove and leaving a first margin of 3 mm.

[0100] Specifically, due to the different densities of copper and cast iron, in order to prevent part of the molten iron from floating on the surface of the copper during fusion welding, which would affect the use effect, a low-hardness copper welding material is needed as a base. A medium-hardness brass welding material is used as a transition, covering part of the molten iron while providing certain support and impact resistance. Finally, a high-hardness aluminum bronze welding material is used to cover the surface to improve the surface hardness and wear resistance.

[0101] It should be further explained that the copper alloy with low hardness, low brittleness and good plasticity can be used as the base layer to better blend with the cast iron material of the mold body. The current is adjusted between 60-90A to reduce the melting amount of the mold body and reduce the floating of the molten iron on the surface of the copper material.

[0102] Fill two layers of medium-hardness brass alloy welding wire to cover the base layer to prevent the molten iron from floating on the surface and provide certain support. The welding current is adjusted between 70-80A to reduce the melting amount of the cast iron material in the mold body while ensuring the mutual fusion of the two copper materials.

[0103] Because the aluminum bronze alloy as the outer layer has high hardness, good wear resistance, but certain brittleness, it requires a transitional intermediate layer for support to reduce cracking or falling off problems.

[0104] Optionally, during the copper alloy welding process, the top of the side wall of the welding groove is welded by pre-stacking. The advantage is that the pre-stacking can alleviate welding stress, deformation and cracking problems at the joint of the fusion zone.

[0105] Furthermore, during the welding operation, try to use low current, short arc welding, low layer temperature, and multi-layer welding operation methods.

[0106] Optionally, during the entire deposition welding process, the wire filling speed is adjusted based on the molten droplet state of the welding wire; it is understandable that due to the poor fluidity of copper-based welding wire, the wire feeding process must be fast in and out to accurately feed the molten droplet into the molten pool, and the wire feeding speed is adjusted according to the molten droplet state to avoid excessive wire feeding to form weld nodules and cause sandwiching.

[0107] Optionally, during the cladding welding process, the length of each weld bead is less than a first length value (eg, 80 mm), and the welding start temperature of each weld bead is 150-200°C.

[0108] After each weld is completed, the weld is hammered using the reverse hammering method; the benefit is that the weld undergoes plastic deformation, releasing stress and reducing crack tendency.

[0109] For step 5, the welding groove can be covered with asbestos blanket and slowly cooled to room temperature to eliminate welding stress. After the mold is cooled, the outer surface of the drawing die is used as the reference plane, and the welding surface is ground, polished and polished in sequence using a grinding wheel, oilstone and different types of sandpaper until the welding surface is consistent with the reference plane.

[0110] In order to understand the method for welding and repairing dissimilar copper materials of a drawing die provided by the present invention in more detail, it is further described in detail in combination with the following experiments.

[0111] like Figure 5 As shown, the present application verifies the pulling phenomenon of two different welding materials through the anti-wear test method.

[0112] Anti-wear test: Traditional cast iron CN400 welding material and aluminum bronze 204A2 welding material were welded on two test rods with a diameter of 30 mm respectively;

[0113] The test rods welded with traditional cast iron welding materials and the test rods welded with aluminum bronze welding materials were subjected to equal pressure rotation friction tests on the test processing plate, which was ST16 cold-rolled steel plate. Among them, the test rod welded with cast iron CN400 welding materials showed obvious burrs and wear defects in the test plate at 13s, while the test rod welded with aluminum bronze 204A2 welding materials showed no obvious burrs and wear defects at 15s. It can be seen from the experiment that the traditional welding method and materials are prone to burrs.

[0114] Production verification phase:

[0115] Traditional method: For molds repaired by welding traditional cast iron CN400 welding materials, since the repair welding materials and the processed sheet materials belong to the same friction pair, the repair welding parts will also have problems with burrs or adhesive chipping during use, resulting in burrs or cracks on the parts, and the parts rework rate is over 80%. Therefore, it is necessary to stop the production line every 150-200 pieces, use sandpaper polishing to eliminate burrs or oilstone polishing to remove chipping, and the single production maintenance time is 15-20 minutes; when 20,000-30,000 pieces are used in production, the gap of the local pressing surface will exceed the tolerance by ≥2mm due to the long-term polishing and polishing of the mold. At this time, in order to ensure the processing accuracy, the mold needs to be repeatedly welded and repaired. Therefore, traditional repair methods will increase production time costs, repair costs, and parts rework costs.

[0116] In this application, the mold is repaired by melting and depositing dissimilar copper materials. Three dissimilar copper welding materials with different properties are used to replace the roughened and damaged parts of the mold body with a copper-based working surface by welding, thereby changing the friction properties between the mold and the processed material, reducing roughening and eliminating the problem of adhesive chipping. Since the density of cast iron is usually in the range of 6.9 to 7.8 g / cm 3 The finish of manual polishing can generally reach Ra0.4-0.8μm, and the density of copper material is usually 8.960g / cm 3 The finish of manual polishing can reach Ra≤0.2μm, so the copper material is better than the cast iron material in anti-picking and anti-adhesion.

[0117] After the die pressing surface in the present application is partially replaced with a dissimilar copper material, the problem of fuzzing is largely controlled. Only when foreign particles are brought in during production will the parts have a single-point fuzzing problem, and there will be no continuous fuzzing or adhesive chipping problems. This will greatly improve the surface quality of the parts, production efficiency, and reduce production costs. After the mold is modified, the number of returned products due to fuzzing has dropped from 80% before the modification to an average of less than 15%, and the single production maintenance time is controlled within 10 minutes. After the die pressing surface is replaced with copper material, more than 15,000 pieces have been produced continuously. There is no deformation or abnormal wear at the welding parts of the dissimilar materials. At the same time, the welding area does not have any welding quality problems such as cracking and falling off after continuous impact, friction, and extrusion. Therefore, the welding process and replacement method adopted in this application can solve the problem of adhesive fuzzing of cold stamping and drawing dies.

[0118] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in a variety of different forms and should not be construed as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for the sake of clarity, the thickness of the layers and regions may be enlarged, and the same reference numerals are used to represent the same devices, and thus their descriptions will be omitted.

Claims

1. A method for welding and repairing dissimilar copper materials of a drawing die, characterized in that: The following steps are involved: Step 1: Setting the argon gas configuration parameters, welding parameters and welding material types of argon arc welding; the welding material types include three copper welding wires of different materials; Step 2: Prepare the welding groove according to the wear area of ​​the drawing die; Step 3: Preheat the welding groove according to the preset welding temperature and preheating area; Step 4: using a preset deposition scheme to perform deposition welding on the welding groove; wherein the height difference between the welding surface after welding and the end surface of the welding groove is greater than or equal to the first margin; Step 5: After cooling to room temperature, use the outer surface of the drawing die as the reference plane to correct the welding surface.

2. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 1, characterized in that: The argon gas configuration parameters include: DC positive electrode welding, argon gas purity ≥ 99.8%, gas flow rate 25-30L / min; Welding parameters include: using a cerium tungsten electrode with a preset diameter, the grinding angle of the cerium tungsten electrode tip is ≤30°, the length of the cerium tungsten electrode extending out of the porcelain nozzle is ≤5mm, and the nozzle uses a porcelain nozzle with a preset caliber; The three types of copper welding wires are respectively a copper alloy welding wire with a hardness of 35-45HB, a brass alloy welding wire with a hardness of 80-85HB, and an aluminum bronze alloy welding wire with a hardness of 130-140HB; wherein the copper alloy welding wire, the brass alloy welding wire and the aluminum bronze alloy welding wire have the same diameter size.

3. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 2, characterized in that: The step 2 specifically includes: Step 201: grinding and removing the worn surface of the drawing die; Step 202: Prepare a U-shaped welding groove; wherein the opening area of ​​the welding groove is larger than the wear area of ​​the drawing die, and the upper edge of the welding groove does not adopt a blunt chamfer design.

4. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 3, characterized in that: The preset welding temperature is 350-500°C, and the preheating area includes the welding groove area and the area extending to the circumference by a preset distance with the opening edge of the welding groove as the boundary; After step 3, the method further includes: a cleaning step of the inner surface of the welding groove.

5. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 4, characterized in that: The preset deposition scheme in step 4 specifically includes: Based on the depth and the first margin of the welding groove, a welding operation is performed on the welding groove according to a preset weld deposition layer ratio and a preset welding sequence; During welding, adjust the welding current according to the type of welding materials, welding sequence, and welding location.

6. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 5, characterized in that: The step of performing welding operation on the welding groove based on the depth of the welding groove and the first margin and according to a preset cladding layer ratio specifically includes: Use copper alloy with hardness of 35-45HB as the base layer of welding groove; Use brass alloy with hardness of 80-85HB as the transition intermediate layer of the welding groove; Aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove.

7. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 6, characterized in that: The copper alloy with hardness of 35-45HB is used as the base layer of the welding groove, which includes: The copper alloy welding wire is used to sequentially complete the deposition welding operation of the top of the side wall of the welding groove, the bottom of the welding groove, and the side wall of the welding groove; wherein the welding current of the copper alloy welding wire is 60-90A; Furthermore, a brass alloy with a hardness of 80-85HB is used as a transition intermediate layer of the welding groove, specifically including: The transition intermediate layer of the welding groove is welded by using a brass alloy welding wire; the welding current of the brass alloy welding wire is 70-80A; Furthermore, an aluminum bronze alloy with a hardness of 130-140HB is used as the outer layer of the welding groove, specifically including: Aluminum bronze alloy welding wire is used to perform deposition welding on the outer layer of the welding groove; the welding current of the aluminum bronze alloy welding wire is 110-120A.

8. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 7, characterized in that: During the welding process of copper alloy welding wire, the top of the side wall of the welding groove is welded by pre-stacking.

9. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 8, characterized in that: During deposition welding, the wire feeding speed is adjusted based on the molten state of the wire.

10. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 9, characterized in that: Also includes: During the deposition welding process, the length of each weld bead is less than the first length value, and the welding start temperature of each weld bead is 150-200° C.; After each weld is completed, the weld is hammered using the reverse hammering method.

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