A method for repairing a drawing die of dissimilar copper materials by welding

Abstract

The application provides a drawing die dissimilar copper material welding repair method and relates to the technical field of automobile part manufacturing. The method comprises the following steps: setting argon arc welding argon configuration parameters, welding parameters and welding material types; the welding material types comprise three different material copper welding wires; according to the wear area of the drawing die, a welding groove is prepared; the welding groove is preheated according to a preset welding temperature and a preheating area; a preset deposition scheme is used 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 a first allowance; after cooling to room temperature, the welding surface is corrected in profile with the outer surface of the drawing die as a reference surface. Compared with the prior art, the application can eliminate the adhesion wear problem caused by mutual friction between the same materials and reduce the pilling defect problem between the two materials, thereby solving the drawing die surface wear problem.

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] Currently, the drawing die for large automotive panels is the most critical process for ensuring part quality, surface finish, production efficiency, and cost. During daily use, the drawing die is subject to sheet metal extrusion and friction, causing adhesion and damage to complex forming areas such as the pressing surface and punch radius. This can lead to various quality defects such as burrs and cracks in the parts. Due to the friction between the mold material and the workpiece, the adhesion and burrs problem cannot be fundamentally eliminated. Therefore, maintenance technicians must frequently polish the mold during production to ensure part quality and mold stability. However, this long-term polishing and grinding damages the mold's working surface, reducing the precision of the stamped part. It can also cause premature wear and failure of the mold, shortening its lifespan.

[0003] At present, the methods used in the industry to prevent adhesive burrs and repair mold burrs mainly include mold surface chrome plating, surface welding repair process, and press surface replacement technology.

[0004] 1. Surface chrome plating: Chrome plating is a preventative process primarily designed to reduce the friction coefficient between the mold surface and the sheet metal, improving the mold's resistance to galling and wear. However, chrome plating is costly and has a short lifespan. In some complex molded parts, the chrome layer can prematurely wear away due to deformation and friction, causing galling and wear to reappear on both surfaces. While repeated chrome plating can reduce galling, cost considerations prevent companies from repeating the process within a certain period of time, requiring continuous polishing and grinding to maintain production.

[0005] 2. Welding Repair Process: Currently, TIG (Titanium Inert Gas) welding is the primary method for repairing mold damage. Fusion welding is performed using consumables of the same or similar material as the mold base. However, these iron-based welding consumables and the workpiece material are similar metal friction pairs. During actual production, the relative sliding friction between the two materials can cause adhesion, galling, and damage.

[0006] 3. Binder surface replacement technology: Based on the fundamental principle of reducing adhesive wear, the deep drawing die's binder surface is completely machined out and replaced with a removable beryllium copper insert. Because beryllium copper does not adhere to the workpiece, it eliminates adhesive galling. However, early signs of adhesive galling on the die surface are often point-like, linear, or small, localized damage. Replacing the entire insert structure would significantly increase repair costs, leading to the seldom-used technology in actual repairs.

[0007] Because existing mold materials, preventive processes, and maintenance technologies are unable to eliminate the problem of adhesive fuzz and damage at low cost and high quality, the mold is repeatedly repaired, ground, and polished during the production and maintenance process, causing the main forming parts of the mold to wear out prematurely or even fail, which not only reduces the service life of the mold, but also increases the company's maintenance and production costs.

[0008] Based on the above content, there is an urgent need for a welding repair method for dissimilar copper materials of a drawing die 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 solution is as follows:

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

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

[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, performing deposition welding on the welding groove; wherein the height difference between the welding surface and the end surface of the welding groove after welding 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: using DC positive electrode welding, argon gas purity ≥ 99.8%, and gas flow rate of 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 diameter;

[0018] The types of welding materials include three types of copper welding wires of different materials, wherein 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 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, step 2 specifically includes:

[0020] Step 201: performing grinding and removing processing on the wear 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 from the opening edge of the welding groove to the circumference by a preset distance;

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

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

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

[0026] During welding, adjust the welding current according to the type of welding materials, deposition sequence, and deposition 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 a hardness of 35-45HB as the base layer of the welding groove;

[0029] Use brass alloy with a 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 for the welding groove, specifically comprising:

[0032] A 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] A brass alloy welding wire is used to perform deposition welding on the transition intermediate layer of the welding groove; 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] An 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 filling speed of the welding wire 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 welding, three copper-based alloy welding materials with different properties are used in the methods of base laying, transition and covering 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 the 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 flow chart of the welding repair method for dissimilar copper materials of a drawing die;

[0045] Figure 2 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 figure is a schematic diagram of the deposition welding sequence of the welding groove;

[0048] Figure 5 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 Schematic diagram of U-shaped welding groove;

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

[0052] Figure 9 Schematic diagram of brass alloy deposited transition intermediate layer;

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

[0054] Figure 11 Schematic diagram of the end face of the drawing die after the profile is corrected. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of this application clearer, the following Figure 1-11 This application is further described in detail. Obviously, the embodiments described are only a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this 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, comprising the following steps:

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

[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, performing deposition welding on the welding groove; wherein the height difference between the welding surface and the end surface of the welding groove after welding 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, this application uses a surfacing method to replace the original roughened and damaged parts with a copper-based working surface by three copper-based alloy welding materials with different properties through base laying, transition and covering methods, 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 based on the damaged position on the drawing die surface, and can maintain the consistency and integrity of the original structure of the die body to the maximum extent. It is low-cost, high-quality, simple to operate, and widely applicable. It can also implement material replacement on multiple important forming parts such as the pressing surface, drawing ribs, punch radius, and the convex and concave dies of the flanging process of the drawing die to eliminate adhesive burrs.

[0066] It can be understood that the welding repair method for dissimilar copper materials of a drawing die provided in this 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, argon gas purity ≥ 99.8%, and gas flow rate is 25-30 L / min;

[0069] 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 from the porcelain nozzle is ≤5mm, and the nozzle is a porcelain nozzle with a diameter of 11mm;

[0070] The types of welding materials include three types of copper welding wires of different materials, wherein 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 diameters of the copper alloy welding wire, the brass alloy welding wire and the aluminum bronze alloy welding wire are the same, all being 2.0 mm.

[0071] It should be noted that while traditional cast iron welding consumables are consistent with the mold's cast iron base material, they can restore mold accuracy. However, in actual production, this does not address the problem of adhesion and galling between the mold and parts. This is because the repair weld area remains unchanged due to friction. Copper, however, has a higher density than cast iron and offers excellent polishing and adhesion resistance. Therefore, copper is used to replace the damaged areas of the original mold with copper by welding to resolve the adhesion and galling issue.

[0072] The step 2 specifically includes:

[0073] Step 201: performing grinding and removing processing on the wear 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 is understood that in this embodiment, a mechanical method may be used, such as using an angle grinder to grind and remove the roughened or 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 sufficient to deposit 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 mold body cast iron material are fused and welded, the solubility of iron in copper is quite small, and iron exists in the form of free iron, which prevents iron and copper from forming 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, preheating the drawing die weld groove before welding, by setting the welding temperature to 350-500°C, is a crucial step in welding dissimilar materials. Due to the significant differences in thermal conductivity and expansion coefficient between the drawing die and the welding wire, the shrinkage rate and shrinkage time after welding differ, resulting in significant welding stress and causing deformation or cracking. Preheating before welding can reduce the shrinkage time difference between the different materials, mitigating welding stress and deformation. It also bakes out oil and moisture from the die itself 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 in 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 inner surface of the welding groove 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 inclusion during welding.

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

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

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

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

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

[0087] Use brass alloy with a 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 weld deposited layer, the brass alloy weld deposited layer and the aluminum bronze alloy weld deposited layer is 2 mm.

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

[0091] Combine Figure 3 As shown, copper alloy welding wire is used to sequentially complete the deposition welding operations 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 deposited by weld beads A, B, and C. The top weld of the side wall corresponds to weld bead A, the bottom weld of the groove corresponds to weld bead B, and the side wall weld 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 formed by depositing weld bead D is welded with a brass alloy welding wire having a welding current of 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 deposited by weld bead E is welded with 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 of welding is deposited to a height of 2 mm;

[0098] Then, brass alloy welding wire was used as the transition intermediate layer, and two layers were 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 110-120 A, 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, a low-hardness copper solder is used as a base to prevent some of the molten iron from floating on the copper surface during fusion welding, thereby affecting the performance. A medium-hardness brass solder is then used as a transitional material, covering some of the molten iron while providing support and impact resistance. Finally, a high-hardness aluminum bronze solder is used to cover the surface, improving surface hardness and wear resistance.

[0101] It should be further explained that using a copper alloy with low hardness, low brittleness and good plasticity as a base layer can 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 at the same time provide a certain degree of support. The welding current is adjusted between 70-80A to reduce the melting amount of the mold body cast iron material while ensuring the mutual fusion of the two copper materials.

[0103] Because the aluminum bronze alloy as the outer layer has high hardness and good wear resistance but is somewhat brittle, a transitional intermediate layer is required for support to reduce cracking or falling off problems.

[0104] Optionally, during the copper alloy welding process, a pre-stacking method is used to weld the top of the side wall of the welding groove. The advantage is that the pre-stacking method 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 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 deposition 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 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 in more detail the method for welding and repairing dissimilar copper materials of a drawing die provided by the present invention, it is further described in detail in combination with the following experiments.

[0111] like Figure 5 As shown, this application uses the anti-wear test method to verify the burring phenomenon of two different welding materials.

[0112] Anti-wear test: Two 30mm diameter test rods were welded with conventional cast iron CN400 welding consumables and aluminum bronze 204A2 welding consumables respectively;

[0113] Test rods welded with conventional cast iron and aluminum-bronze consumables were subjected to equal-pressure rotational friction tests on ST16 cold-rolled steel plates. The cast iron CN400 consumable rod exhibited significant galling wear defects after 13 seconds, while the aluminum-bronze 204A2 consumable rod showed no galling defects after 15 seconds. The experiments demonstrate that conventional welding methods and materials are prone to galling.

[0114] Production verification phase:

[0115] Traditional methods: Molds repaired by welding traditional cast iron CN400 welding consumables. Because the repair material and the workpiece form the same friction pair, the repaired area can experience burrs or adhesion buildup on the workpiece during use, leading to burrs or cracks on the parts, resulting in a rework rate exceeding 80%. Therefore, the production line must be stopped every 150-200 pieces to remove burrs with sandpaper polishing or buildup with oilstones, with each maintenance session lasting 15-20 minutes. After every 20,000-30,000 pieces, the prolonged polishing and polishing can cause gaps on the pressing surfaces to exceed 2mm. To maintain machining accuracy, the mold must be repeatedly welded and repaired. Consequently, traditional repair methods increase production time, repair costs, and part rework costs.

[0116] In this application, a mold is repaired by depositing dissimilar copper materials. Three different copper brazing 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. This changes the friction between the mold and the processed material, reduces roughening and eliminates 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 burrs is largely controlled. During production, only when foreign particles are introduced will the parts have a single-point burr problem, and there will be no continuous burrs 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 burrs has dropped from 80% before the modification to an average of less than 15%, and the maintenance time for a single production is controlled within 10 minutes. After the die pressing surface was replaced with copper material, more than 15,000 pieces have been produced continuously. There has been no deformation or abnormal wear at the dissimilar material welding parts. At the same time, the fusion zone has not had 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 adhesive burrs problem 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 can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of this 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 layers and regions may be exaggerated, 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: Set the argon gas configuration parameters, welding parameters, and welding material types for argon arc welding; the welding material types include three different copper welding wires; 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; 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, performing deposition welding on the welding groove; wherein the height difference between the welding surface and the end surface of the welding groove after welding 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 surface to correct the welding surface; The preset deposition plan in step 4 specifically includes: Based on the depth of the welding groove and the first margin, a welding operation is performed on the welding groove according to a preset deposition layer ratio, specifically including: Use copper alloy with a hardness of 35-45HB as the base layer of the welding groove; Use brass alloy with a 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.

2. The drawing die dissimilar copper material welding repair method according to claim 1, characterized in that: The argon gas configuration parameters include: DC positive electrode welding, argon purity ≥ 99.8%, and gas flow rate of 25-30 L / 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 diameter; The copper alloy welding wire, the brass alloy welding wire and the aluminum bronze alloy welding wire have the same diameter.

3. The drawing die dissimilar copper material welding repair method according to claim 2, characterized in that: The step 2 specifically includes: Step 201: performing grinding and removing processing on the wear 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 drawing die dissimilar copper material welding repair method 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 of the opening edge of the welding groove by a preset distance; After step 3, the method further includes: a step of cleaning the inner surface of the welding groove.

5. The drawing die dissimilar copper material welding repair method according to claim 4, characterized in that: The preset deposition plan in step 4 specifically includes: During welding, adjust the welding current according to the type of welding materials, deposition sequence, and deposition location.

6. The drawing die dissimilar copper material welding repair method according to claim 5, characterized in that: The copper alloy with hardness of 35-45HB is used as the base layer of the welding groove, specifically including: A 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: A brass alloy welding wire is used to perform deposition welding on the transition intermediate layer of the welding groove; 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: An 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.

7. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 6, characterized in that: During the welding process of copper alloy welding wire, the pre-stacking method is adopted to weld the top of the side wall of the welding groove.

8. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 7, characterized in that: During deposition welding, the wire feeding speed is adjusted based on the molten droplet state of the wire.

9. The method for welding and repairing dissimilar copper materials of a drawing die according to claim 8, 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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