Method for spraying 304 austenitic stainless steel on surface of copper plate through stud welding

Abstract

The invention provides a method for spraying 304 austenitic stainless steel on the surface of a copper plate through stud welding. The method specifically comprises the steps that firstly, the surface of the copper plate is treated; then, welding voltage is set on an energy storage type stud welding machine, and an end block of the 304 austenitic stainless steel stud is driven into the copper plate through a stud welding gun; electrifying the stud welding gun to ignite the electric arc, fully melting the end block and the copper plate at the end block, and welding the 304 austenitic stainless steel stud on the copper plate after the molten metal is naturally cooled and solidified; and knocking off a boss and a screw rod of the 304 austenitic stainless steel stud, and observing that the solidified 304 austenitic stainless steel metal layer covers the surface of the copper plate. Stud welding spraying is used, a cladding layer is formed on the surface of the end block and the surface of the copper plate at high temperature, and after molten metal is solidified, high-strength combination is formed between the 304 austenitic stainless steel metal layer and the copper plate; and the 304 austenitic stainless steel metal layer coated on the copper plate is high in hardness and good in wear resistance.

Description

Technical Field

[0001] The invention relates to the technical field of metal surface spraying, and in particular to a method for spraying 304 austenitic stainless steel on the surface of a copper plate by utilizing stud welding. Background Art

[0002] 304 austenitic stainless steel has high strength and hardness, while copper plate has good ductility and toughness. Combining the two can improve the mechanical strength and stability of the overall structure. Copper plate has excellent electrical conductivity, while 304 austenitic stainless steel has relatively weak electrical conductivity. Spraying 304 austenitic stainless steel on copper plate can take advantage of the high electrical conductivity of copper plate to achieve good current transmission. At present, this metal structure of 304 austenitic stainless steel sprayed on copper plate has a wide range of industrial applications, specifically:

[0003] ①Electrical industry

[0004] Busbar connection: In power systems, copper is often used as busbar material, and copper has good electrical conductivity. 304 austenitic stainless steel is sprayed on the copper plate. This metal structure can be connected to electrical equipment or wires. The strength and corrosion resistance of 304 austenitic stainless steel ensure the reliability of the connection, while the copper plate ensures efficient current transmission.

[0005] Switchgear: In high-voltage switchgear, 304 austenitic stainless steel is sprayed on copper plate. This metal structure has reliable connection and conductivity. This metal structure can be used to fix and connect switch components and withstand mechanical stress and current load. At the same time, the corrosion resistance of 304 austenitic stainless steel can protect the connection parts from environmental factors.

[0006] ②Electronic manufacturing

[0007] Circuit board heat dissipation: In some high-performance electronic devices, circuit boards generate a lot of heat. Copper plates are often used as heat sink materials to improve heat dissipation efficiency. 304 austenitic stainless steel sprayed on copper plates. This metal structure can be used to fix electronic components or radiators to ensure good thermal conduction and mechanical stability.

[0008] RF equipment: In RF communications and electronic equipment, precise connections and good electromagnetic shielding performance are required. 304 austenitic stainless steel sprayed on copper plate. This metal structure can be used to fix RF components, antennas, etc. At the same time, the conductivity and electromagnetic shielding performance of the copper plate can reduce signal interference.

[0009] ②Chemical and petroleum industries

[0010] Pipeline connection: In the chemical and petroleum industries, pipeline systems need to withstand high pressure, high temperature and corrosion. 304 austenitic stainless steel sprayed on copper plate can be used to manufacture flanges, valves and other parts for connecting pipelines. The corrosion resistance and strength of 304 austenitic stainless steel can ensure the reliability of the connecting parts, while the thermal conductivity of the copper plate helps the pipeline system dissipate heat and reduce the temperature of the pipeline system.

[0011] Container manufacturing: In chemical and petroleum storage containers, corrosion-resistant materials are required. 304 austenitic stainless steel sprayed on copper plate. This metal structure can be used to fix the internal parts of the container, such as agitators, heaters, etc. At the same time, the thermal conductivity of the copper plate helps to evenly heat or cool the medium in the container.

[0012] ④ Mechanical manufacturing

[0013] Mold manufacturing: In mold manufacturing, materials with high strength and good thermal conductivity are required. 304 austenitic stainless steel sprayed on copper plate can be used to manufacture the cooling system or heating system of the mold. The strength of 304 austenitic stainless steel can withstand the mechanical stress of the mold, while the thermal conductivity of the copper plate can ensure rapid heat transfer and improve the production efficiency and quality of the mold.

[0014] Mechanical parts connection: In some special mechanical parts, parts of different materials need to be connected together. The metal structure of 304 austenitic stainless steel sprayed on copper plate can provide reliable connection and meet the performance requirements of different materials. For example, in some mechanical parts under high temperature, high pressure or corrosive environment, this connection method can improve the reliability and service life of parts.

[0015] The existing technology is to use the electroplating method to spray 304 austenitic stainless steel on the copper plate. The specific operation method is: 1. Clean the 304 austenitic stainless steel studs and the copper plate separately. 2. Put the 304 austenitic stainless steel studs and the copper plate into the same electroplating tank, and fix them in the electroplating tank respectively, and ensure that there is an appropriate distance between the 304 austenitic stainless steel studs and the copper plate. 3. Connect the 304 austenitic stainless steel studs to the anode of the power supply and the copper plate to the cathode of the power supply. 4. Set the electroplating parameters such as current, voltage, temperature and time on the electroplating controller. 5. Pour the configured electroplating solution into the electroplating tank, turn on the power supply for electroplating; during the electroplating process, the 304 austenitic stainless steel studs at the anode lose electrons, and the copper plate at the cathode gains electrons; through the principle of electrolysis, the metal electrons decomposed by the 304 austenitic stainless steel studs are adsorbed to the surface of the copper plate, and a 304 austenitic stainless steel coating is plated on the surface of the copper plate. 6. After the electroplating is completed, turn off the power, take out the 304 austenitic stainless steel studs and the plated copper plate, and then clean the 304 austenitic stainless steel studs and the plated copper plate with pure water to remove the residual electroplating liquid and impurities on the surface, and finally blow dry.

[0016] However, there are many disadvantages of electroplating, specifically, 1. The bonding force is relatively weak: electroplating is to deposit metal ions on the surface of the substrate to form a coating through electrolysis. The bonding strength between the coating (304 austenitic stainless steel coating) and the substrate (copper plate) is relatively low, and the coating is easy to fall off from the substrate. 2. The process is complex and time-consuming: the electroplating process includes surface pretreatment (such as degreasing, pickling, activation, etc.), electroplating operation and post-treatment (such as cleaning, drying, etc.). Each link requires strict operation and control, and the whole process takes a long time. 3. Large equipment investment: electroplating requires a series of professional equipment such as electroplating tanks, power supplies, electrodes, stirring devices, filtering equipment, etc., and the purchase and installation costs of these equipment are high. In addition, in order to ensure the quality of electroplating, the equipment needs to be regularly maintained and maintained, which increases the cost of equipment use. 4. High material cost: A large amount of electroplating solution is required in the electroplating process. The composition of the electroplating solution is complex, including metal salts, conductive salts, buffers, additives and other chemical substances. The price of these chemical substances is high, and they will be continuously consumed during use and need to be replenished regularly. 5. The electroplating process will produce a large amount of waste water, waste gas and waste residue, which contain heavy metal ions, acids, alkalis and other harmful substances. If they are discharged directly without treatment, they will cause serious pollution to the environment. Summary of the invention

[0017] The purpose of the present invention is to provide a method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding, so as to overcome the shortcomings of the existing electroplating method, such as low bonding degree between the coating and the substrate, complex process, environmental pollution and high manufacturing cost.

[0018] In order to achieve the above object, the present invention adopts the following technical solutions to achieve it.

[0019] The method of spraying 304 austenitic stainless steel on the surface of copper plate by stud welding, the specific operation steps are as follows:

[0020] Step 1, first prepare a copper plate, a stud welding system and a plurality of 304 austenitic stainless steel studs; wherein the stud welding system is composed of a storage stud welding machine and a stud welding gun, which are connected by a cable; the 304 austenitic stainless steel stud is composed of a screw rod, a boss and an end block arranged in sequence from top to bottom;

[0021] Step 2, treat the surface of the copper plate to ensure that the surface of the copper plate is smooth and clean, free of impurities and oxide layer, and ensure that the surface roughness Ra of the copper plate is less than 1mm;

[0022] Step 3, first set the welding voltage to 44V~45V on the energy storage stud welding machine, then insert the screw of the 304 austenitic stainless steel stud into the chuck of the stud welding gun, and then use the stud welding gun to drive the end block of the 304 austenitic stainless steel stud into the copper plate; the stud welding gun is powered on to ignite the arc, the end block and the copper plate at the end block are fully melted, and after the molten metal melt is naturally cooled and solidified, the 304 austenitic stainless steel stud is welded to the copper plate; then, the boss and screw of the 304 austenitic stainless steel stud are knocked off, and the solidified 304 austenitic stainless steel metal layer is observed to cover the surface of the copper plate, and the single spraying operation is completed;

[0023] Step 4, determine a new spraying position, spray a new 304 austenitic stainless steel metal layer on the copper plate, repeat multiple times, and make the 304 austenitic stainless steel metal layer completely or partially cover the copper plate surface according to the use requirements.

[0024] The specific steps of step 2 above are:

[0025] 2.1 Finely polish and clean the surface of the copper plate to ensure that the surface of the copper plate is smooth and free of impurities;

[0026] 2.2 Perform pickling and surface chemical treatment on the copper plate: first soak the copper plate in the pickling solution for 1 minute, then rinse the pickling solution on the copper plate with water, and then blow the copper plate dry; the pickling solution can remove part of the oxide layer on the surface of the copper plate;

[0027] 2.3 Activate the copper plate surface: Apply a layer of surfactant on the copper plate surface and then dry it naturally; the surfactant can completely remove the residual oxide layer on the copper plate surface;

[0028] 2.4 Use a laser focusing microscope to observe the roughness of the copper plate surface to ensure that the surface roughness Ra of the copper plate is less than 1 mm; if the surface roughness Ra of the copper plate is greater than 1 mm, return to step 2.2 to continue processing.

[0029] Wherein, in 2.2 of step 2, the pickling solution is formed by mixing a nitric acid solution and a hydrofluoric acid solution in a volume ratio of 1:23; wherein the volume molar concentration of the nitric acid solution is 0.1 mol / L, and the mass percentage concentration of the hydrofluoric acid solution is 10%.

[0030] Wherein, in step 2.3, the surfactant is a hydrochloric acid solution, and the mass percentage concentration of the hydrochloric acid solution is 10%.

[0031] The specific steps of step 3 above are:

[0032] 3.1 Use a clamp to hold the copper plate;

[0033] 3.2 Connect the energy storage stud welding machine to the positive pole of the power supply and the copper plate to the negative pole of the power supply;

[0034] 3.3 Set the welding voltage on the energy storage stud welding machine to 44V~45V;

[0035] 3.4 Insert the screw of the 304 austenitic stainless steel stud into the chuck of the stud welding gun muzzle, and the boss and end block of the 304 austenitic stainless steel stud are located outside the muzzle of the stud welding gun;

[0036] 3.5 Point the muzzle of the stud welding gun downward, make the end block of the 304 austenitic stainless steel stud contact the copper plate, and ensure that the 304 austenitic stainless steel stud and the copper plate remain vertical;

[0037] 3.6 Press the stud welding gun downward to apply a constant load of 55N to the 304 austenitic stainless steel stud and drive the end block into the copper plate;

[0038] 3.7 Trigger the switch of the stud welding gun, power on the stud welding gun to ignite the arc, fully melt the end block and the copper plate at the end block, and the arc welding lasts for 0.3s; after the molten metal melt cools and solidifies naturally, the 304 austenitic stainless steel stud is welded to the copper plate;

[0039] 3.8 Knock off the boss and screw of the 304 austenitic stainless steel stud, and observe that the solidified 304 austenitic stainless steel metal layer covers the surface of the copper plate, and the single spraying operation is completed.

[0040] The beneficial effects of the present invention are:

[0041] 1. The present invention uses stud welding spraying to form a cladding layer between the end block of the 304 austenitic stainless steel stud and the surface of the copper plate at high temperature. After the molten metal melt solidifies, a very high bonding strength is generated between the 304 austenitic stainless steel metal layer and the copper plate, and there is no gap or stratification between the two, so that the 304 austenitic stainless steel metal layer can withstand large tension, pressure and shear force, and is not easy to fall off from the copper plate. It is suitable for workpieces with high requirements for bonding strength.

[0042] 2. The present invention uses stud welding spraying, which only requires simple cleaning of the copper plate surface, setting the voltage parameters of the energy storage stud welding machine, driving the end block of the 304 austenitic stainless steel stud into the copper plate, and energizing and striking the arc to complete the spraying. The operation is relatively simple and easy to master.

[0043] 3. The present invention utilizes stud welding spraying to spray a 304 austenitic stainless steel metal layer on the surface of the copper plate, and the hardness thereof is 210HV to 505HV. The hardness value within this range can improve the wear resistance of the 304 austenitic stainless steel metal layer, reduce the wear marks and damage on the surface of the 304 austenitic stainless steel metal layer caused by friction, and extend the service life of the copper plate; it can also enhance the deformation resistance of the copper plate, and make the copper plate less prone to plastic deformation when subjected to a certain pressure, tensile force or bending force; it can enhance the structural strength, and for some structural parts that need to withstand larger loads or stresses, it can improve their reliability and safety.

[0044] 4. The stud welding spraying of the present invention is not only suitable for spraying a 304 austenitic stainless steel metal layer on the entire area of ​​a copper plate, but also suitable for spraying a 304 austenitic stainless steel metal layer on a local area of ​​a copper plate.

[0045] 5. In large-scale production, the stud welding spraying process only requires two types of equipment: energy storage stud welding machine and stud welding gun. The equipment investment is relatively low, and the equipment is small in size, occupies less space, and is easy to install and use.

[0046] 6. During stud welding, the stud welding gun is powered on to ignite the arc. The arc welding lasts only 0.3s, and the heat affected zone is very small. The short-term welding and small-scale heat impact make the copper plate less likely to deform, so there is no need to trim the copper plate after welding.

[0047] 7. Use stud welding to weld 304 austenitic stainless steel studs to the front of the copper plate. Because the stud welding has a relatively shallow penetration depth, there is no mark on the back of the copper plate and no treatment is required after welding. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 This is a schematic diagram of the connection between the energy storage stud welding machine, the stud welding gun, the copper plate and the power supply in the present invention;

[0049] Figure 2It is a schematic diagram of the structure of the 304 austenitic stainless steel stud used in the present invention;

[0050] Figure 3 This is a morphology image of a 304 austenitic stainless steel metal layer coated on the surface of a copper plate in step 3.8 of Example 1 of the present invention;

[0051] Figure 4 In Example 1 of the present invention, Figure 3 For the sample, determine the welding center P1, and then select a 10×10mm square P welding area map with P1 as the center;

[0052] Figure 5 In Example 1 of the present invention, a plurality of hardness test points are selected in the P-part welding area, and a distribution diagram of the plurality of hardness test points;

[0053] Figure 6 In Example 1 of the present invention, a scanning electron microscope is used to Figure 5 The welding center P1 in the figure is magnified 10000 times, and the surface morphology of the 304 austenitic stainless steel metal layer is observed;

[0054] Figure 7 In Example 1 of the present invention, Figure 5 The morphology of the 304 austenitic stainless steel metal layer covering the copper plate is observed by magnifying the welding center P1 by 20 times on the AA section of the copper plate.

[0055] Figure 8 This is a morphology image of a 304 austenitic stainless steel metal layer coated on the surface of a copper plate in step 3.8 of Example 2 of the present invention;

[0056] Fig. 9 In Example 2 of the present invention, Figure 8 For the sample, determine the welding center B1, and then select a 10×10mm square B welding area map with B1 as the center;

[0057] Fig.10 In Example 2 of the present invention, multiple hardness test points are selected in the welding area of ​​part B, and the distribution diagram of the multiple hardness test points;

[0058] Fig.11 In Example 2 of the present invention, a scanning electron microscope is used to Fig.10 The welding center B1 in the figure is magnified 10000 times, and the surface morphology of the 304 austenitic stainless steel metal layer is observed;

[0059] Fig.12 In Example 2 of the present invention, Fig.10The DD section of the welding center B1 is taken as the object, and the scanning electron microscope is used to magnify it 20 times to observe the morphology of the 304 austenitic stainless steel metal layer covering the copper plate;

[0060] In the figure, 1. copper plate, 2. energy storage stud welding machine, 3. stud welding gun, 4. screw, 5. boss, 6. end block, 7. 304 austenitic stainless steel stud, 8. 304 austenitic stainless steel metal layer. DETAILED DESCRIPTION

[0061] The present invention provides a method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding, and the specific operation steps are as follows:

[0062] Step 1, first prepare a copper plate 1, a stud welding system and a plurality of 304 austenitic stainless steel studs 7; wherein the stud welding system is composed of a storage type stud welding machine 2 and a stud welding gun 3, and the storage type stud welding machine 2 and the stud welding gun 3 are connected by a cable; Figure 2 As shown, the 304 austenitic stainless steel stud 7 is composed of a screw rod 4, a boss 5 and an end block 6 which are arranged in sequence from top to bottom;

[0063] Step 2, treating the surface of the copper plate 1 to ensure that the surface of the copper plate 1 is smooth and clean, free of impurities and oxide layer, and that the surface roughness Ra of the copper plate 1 is less than 1 mm;

[0064] Step 3, first set the welding voltage to 44V~45V on the energy storage stud welding machine 2, then insert the screw 4 of the 304 austenitic stainless steel stud 7 into the chuck of the muzzle of the stud welding gun 3, and then use the stud welding gun 3 to drive the end block 6 of the 304 austenitic stainless steel stud 7 into the inside of the copper plate 1; the stud welding gun 3 is then powered on to ignite the arc, and the end block 6 and the copper plate 1 at the end block 6 are fully melted, and after the molten metal melt is naturally cooled and solidified, the 304 austenitic stainless steel stud 7 is welded to the copper plate 1; then, the boss 5 and the screw 4 of the 304 austenitic stainless steel stud 7 are knocked off, and it is observed that the solidified 304 austenitic stainless steel metal layer 8 covers the surface of the copper plate 1, and the single spraying operation is completed;

[0065] Step 4, determine a new spraying position, spray a new 304 austenitic stainless steel metal layer 8 on the copper plate 1, repeat multiple times, and make the 304 austenitic stainless steel metal layer 8 completely or partially cover the surface of the copper plate 1 according to usage requirements.

[0066] The effects of the present invention are further described in detail below in conjunction with specific embodiments:

[0067] Example 1

[0068] The present invention provides a method for spraying 304 austenitic stainless steel on the surface of a copper plate by using stud welding, and the specific operation steps are as follows:

[0069] Step 1, first prepare a copper plate 1, a stud welding system and a plurality of 304 austenitic stainless steel studs 7.

[0070] Step 2, treating the surface of the copper plate 1:

[0071] 2.1 Finely polish and clean the surface of the copper plate 1 to ensure that the surface of the copper plate 1 is smooth and free of impurities; the copper plate 1 used in this embodiment is a T2 copper plate, the copper content of T2 copper is above 99.90%, and the total impurity content does not exceed 0.1%;

[0072] 2.2 Perform pickling and surface chemical treatment on the surface of the copper plate 1: first immerse the copper plate 1 in the pickling solution for 1 minute, then rinse the pickling solution on the copper plate 1 with water, and then blow dry the copper plate 1; the pickling solution can remove a part of the oxide layer on the surface of the copper plate 1; wherein the pickling solution is a mixture of nitric acid solution and hydrofluoric acid solution in a volume ratio of 1:23;

[0073] The nitric acid solution used in this embodiment was purchased directly from the market. Its manufacturer is: Fuzhou Wei Bo Kang Biotechnology Co., Ltd. The volume molar concentration of the nitric acid solution is 0.1 mol / L;

[0074] The hydrofluoric acid solution used in this embodiment is purchased directly from the market. Its manufacturer is Haibiao Technology Co., Ltd. The mass percentage concentration of the hydrofluoric acid solution is 10%;

[0075] 2.3 Activate the surface of the copper plate 1: Apply a layer of surfactant on the surface of the copper plate with a brush, and then dry it naturally; the surfactant can completely remove the residual oxide layer on the surface of the copper plate 1;

[0076] The surfactant used in this embodiment is a hydrochloric acid solution, which is purchased directly from the market. Its manufacturer is: Beijing Zhongke Erhuan Technology Co., Ltd. Its product specifications are: SRRM Zhongke Erhuan Standard, and the mass percentage concentration of the hydrochloric acid solution is 10%;

[0077] 2.4 Use a laser focusing microscope to observe the roughness of the surface of the copper plate 1 to ensure that the surface roughness Ra of the copper plate 1 is less than 1 mm; if the surface roughness Ra of the copper plate 1 is greater than 1 mm, return to step 2.2 to continue processing.

[0078] Step 3, spraying a 304 austenitic stainless steel metal layer 8 onto the copper plate 1 using a stud welding system:

[0079] 3.1 Clamp the copper plate 1 with a clamp;

[0080] 3.2 As Figure 1As shown, the energy storage stud welding machine 2 and the stud welding gun 3 are connected by a cable; the energy storage stud welding machine 2 is connected to the positive electrode of the power supply, and the copper plate 1 is connected to the negative electrode of the power supply;

[0081] 3.3 Set the welding voltage on the energy storage stud welding machine 2 to 44V;

[0082] 3.4 Insert the screw rod 4 of the 304 austenitic stainless steel stud 7 into the chuck of the stud welding gun 3, and the boss 5 and the end block 6 of the 304 austenitic stainless steel stud 7 are located outside the stud welding gun 3, as shown in FIG. Figure 1 As shown;

[0083] 3.5 Point the muzzle of the stud welding gun 3 downward, make the end block 6 of the 304 austenitic stainless steel stud 7 contact the copper plate 1, and ensure that the 304 austenitic stainless steel stud 7 and the copper plate 1 remain vertical, such as Figure 1 As shown;

[0084] 3.6 Press the stud welding gun 3 downward, apply a constant load of 55N to the 304 austenitic stainless steel stud 7, and drive the end block 6 into the copper plate 1;

[0085] 3.7 Trigger the switch of the stud welding gun 3, and the stud welding gun 3 is powered on to ignite the arc, so that the end block 6 and the copper plate 1 at the end block 6 are fully melted, and the arc welding lasts for 0.3s; after the molten metal melt is naturally cooled and solidified, the 304 austenitic stainless steel stud 7 is welded to the copper plate 1; under a voltage of 44V, the heat generated by welding can form a firm bond between the end block 6 of the 304 austenitic stainless steel stud 7 and the copper plate 1;

[0086] 3.8 Use a hammer to knock off the boss 5 and screw 4 of the 304 austenitic stainless steel stud 7, and observe that the solidified 304 austenitic stainless steel metal layer 8 covers the surface of the copper plate 1, as shown in FIG. Figure 3 As shown, a single spraying operation is completed;

[0087] Step 4, determine a new spraying position, spray a new 304 austenitic stainless steel metal layer 8 on the copper plate 1, repeat steps 3.4 to 3.8 multiple times, and make the 304 austenitic stainless steel metal layer 8 completely or partially cover the surface of the copper plate 1 according to usage requirements.

[0088] The energy storage stud welding machine 2 used in Example 1 has a brand of FUNISI, a model of STUD WELDER 8100, and a manufacturer of FUNISI, Austria. The stud welding gun 3 used in Example 1 has a brand of Black Wolf, a model of LZHQ-02, and a manufacturer of Changzhou Jinqiu Welding and Cutting Equipment Co., Ltd.

[0089] In step 3.8 of Example 1, the morphology of the 304 austenitic stainless steel metal layer 8 covering the surface of the copper plate 1 is as follows: Figure 3 As shown, from Figure 3 It can be seen that the surface of the 304 austenitic stainless steel metal layer 8 formed after welding is relatively flat, making the overall effect after spraying more beautiful. Good welding quality allows the 304 austenitic stainless steel metal layer 8 to provide better corrosion protection for the copper plate 1, and the 304 austenitic stainless steel metal layer 8 can prevent moisture, oxygen and corrosive substances in the external environment from corroding the copper plate 1.

[0090] by Figure 3 For the sample, determine the welding center P1, and then select a 10×10mm square P welding area with P1 as the center, such as Figure 4 As shown. Figure 4 Select multiple hardness test points in the P welding area, such as Figure 5 As shown, hardness tests are performed on these multiple hardness test points, and the test results are as follows:

[0091] The hardness of P1 is 501.2HV, the hardness of P2 is 392.9HV, and the hardness of P3 is 319.4HV.

[0092] The hardness of P4 is 241.1HV, the hardness of P5 is 473.7HV, and the hardness of P6 is 418.1HV.

[0093] The hardness of P7 is 343.3HV, the hardness of P8 is 458.4HV, and the hardness of P9 is 357.2HV.

[0094] The hardness of P10 is 305.2HV, the hardness of P11 is 429.6HV, and the hardness of P12 is 311.1HV.

[0095] The hardness of P13 is 233.1HV, the hardness of P14 is 433.6HV, and the hardness of P15 is 334.6HV.

[0096] The hardness of P16 is 296.8HV, the hardness of P17 is 372.9HV, and the hardness of P18 is 307.2HV.

[0097] The hardness of P19 is 213.5HV;

[0098] From the above data, we can see that the metal hardness at the welding center P1 is the highest, with a hardness value of up to 501.2HV. The closer the area is to the welding center P1, the higher the hardness is, because this area undergoes rapid heating and cooling during the welding process, forming fine grains and strengthening phases. As the distance from the welding center P1 increases, the hardness gradually decreases, because the area far away from the welding center P1 is less affected by heat and the organizational structure does not change much.

[0099] like Figure 6 As shown, by scanning electron microscopy Figure 5 The welding center P1 is magnified 10000 times, and it can be clearly observed that the surface flatness of the 304 austenitic stainless steel metal layer 8 covering the copper plate 1 is relatively high, which to some extent indicates that the uniformity of the 304 austenitic stainless steel metal layer 8 is relatively good. Figure 6 It can be seen that the metal particles in the 304 austenitic stainless steel metal layer 8 are spherical in shape. Spherical metal particles usually have good fluidity and filling properties, and can make the 304 austenitic stainless steel metal layer 8 more dense. Figure 5 On the AA section of the welding center P1, the scanning electron microscope is used to magnify it 20 times, as shown in Figure 7 As shown, it can be seen that: there is no gap at the junction of the copper plate 1 and the 304 austenitic stainless steel metal layer 8, and there is no delamination between the copper plate 1 and the 304 austenitic stainless steel metal layer 8, indicating that the bonding between the two is high, so that the 304 austenitic stainless steel metal layer 8 is not easy to fall off from the copper plate 1.

[0100] Example 2

[0101] The present invention provides a method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding, and the specific operation steps are as follows:

[0102] Step 1, first prepare a copper plate 1, a stud welding system and a plurality of 304 austenitic stainless steel studs 7.

[0103] Step 2, treating the surface of the copper plate 1:

[0104] 2.1 Finely polish and clean the surface of the copper plate 1 to ensure that the surface of the copper plate 1 is smooth and free of impurities; the copper plate 1 used in this embodiment is a T2 copper plate, the copper content of T2 copper is above 99.90%, and the total impurity content does not exceed 0.1%;

[0105] 2.2 Perform pickling and surface chemical treatment on the surface of the copper plate 1: first immerse the copper plate 1 in the pickling solution for 1 minute, then rinse the pickling solution on the copper plate 1 with water, and then blow dry the copper plate 1; the pickling solution can remove a part of the oxide layer on the surface of the copper plate 1; wherein the pickling solution is a mixture of nitric acid solution and hydrofluoric acid solution in a volume ratio of 1:23;

[0106] The nitric acid solution used in this embodiment was purchased directly from the market. Its manufacturer is: Fuzhou Wei Bo Kang Biotechnology Co., Ltd. The volume molar concentration of the nitric acid solution is 0.1 mol / L;

[0107] The hydrofluoric acid solution used in this embodiment is purchased directly from the market. Its manufacturer is Haibiao Technology Co., Ltd. The mass percentage concentration of the hydrofluoric acid solution is 10%;

[0108] 2.3 Activate the surface of the copper plate 1: Apply a layer of surfactant on the surface of the copper plate with a brush, and then dry it naturally; the surfactant can completely remove the residual oxide layer on the surface of the copper plate 1;

[0109] The surfactant used in this embodiment is a hydrochloric acid solution, which is purchased directly from the market. Its manufacturer is: Beijing Zhongke Erhuan Technology Co., Ltd. Its product specifications are: SRRM Zhongke Erhuan Standard, and the mass percentage concentration of the hydrochloric acid solution is 10%;

[0110] 2.4 Use a laser focusing microscope to observe the roughness of the surface of the copper plate 1 to ensure that the surface roughness Ra of the copper plate 1 is less than 1 mm; if the surface roughness Ra of the copper plate 1 is greater than 1 mm, return to step 2.2 to continue processing.

[0111] Step 3, spraying a 304 austenitic stainless steel metal layer 8 onto the copper plate 1 using a stud welding system:

[0112] 3.1 Clamp the copper plate 1 with a clamp;

[0113] 3.2 As Figure 1 As shown, the energy storage stud welding machine 2 and the stud welding gun 3 are connected by a cable; the energy storage stud welding machine 2 is connected to the positive electrode of the power supply, and the copper plate 1 is connected to the negative electrode of the power supply;

[0114] 3.3 Set the welding voltage on the energy storage stud welding machine 2 to 45V;

[0115] 3.4 Insert the screw rod 4 of the 304 austenitic stainless steel stud 7 into the chuck of the stud welding gun 3, and the boss 5 and the end block 6 of the 304 austenitic stainless steel stud 7 are located outside the stud welding gun 3, as shown in FIG. Figure 1 As shown;

[0116] 3.5 Point the muzzle of the stud welding gun 3 downward, make the end block 6 of the 304 austenitic stainless steel stud 7 contact the copper plate 1, and ensure that the 304 austenitic stainless steel stud 7 and the copper plate 1 remain vertical, such as Figure 1 As shown;

[0117] 3.6 Press the stud welding gun 3 downward, apply a constant load of 55N to the 304 austenitic stainless steel stud 7, and drive the end block 6 into the copper plate 1;

[0118] 3.7 Trigger the switch of the stud welding gun 3, and the stud welding gun 3 is powered on to ignite the arc, so that the end block 6 and the copper plate 1 at the end block 6 are fully melted, and the arc welding lasts for 0.3s; after the molten metal melt is naturally cooled and solidified, the 304 austenitic stainless steel stud 7 is welded to the copper plate 1; under a voltage of 45V, the heat generated by welding can form a firm bond between the end block 6 of the 304 austenitic stainless steel stud 7 and the copper plate 1;

[0119] 3.8 Use a hammer to knock off the boss 5 and screw 4 of the 304 austenitic stainless steel stud 7, and observe that the solidified 304 austenitic stainless steel metal layer 8 covers the surface of the copper plate 1, as shown in FIG. Figure 8 As shown, a single spraying operation is completed;

[0120] Step 4, determine a new spraying position, spray a new 304 austenitic stainless steel metal layer 8 on the copper plate 1, repeat steps 3.4 to 3.8 multiple times, and make the 304 austenitic stainless steel metal layer 8 completely or partially cover the surface of the copper plate 1 according to usage requirements.

[0121] The energy storage stud welding machine 2 used in Example 2 has a brand of FUNISI, a model of STUD WELDER 8100, and a manufacturer of Austrian Funisi. The stud welding gun 3 used in Example 2 has a brand of Black Wolf, a model of LZHQ-02, and a manufacturer of Changzhou Jinqiu Welding and Cutting Equipment Co., Ltd.

[0122] In step 3.8 of Example 2, the morphology of the 304 austenitic stainless steel metal layer 8 covering the surface of the copper plate 1 is as follows: Figure 8 As shown, from Figure 8 It can be seen that the surface of the 304 austenitic stainless steel metal layer 8 formed after welding is relatively flat, making the overall effect after spraying more beautiful. Good welding quality allows the 304 austenitic stainless steel metal layer 8 to provide better corrosion protection for the copper plate 1, and the 304 austenitic stainless steel metal layer 8 can prevent moisture, oxygen and corrosive substances in the external environment from corroding the copper plate 1.

[0123] by Figure 8 For the sample, determine the welding center B1, and then select a 10×10mm square B welding area with B1 as the center, such as Fig. 9 As shown. Fig. 9 Select multiple hardness test points in the B welding area, such as Fig.10 As shown, hardness tests are performed on these multiple hardness test points, and the test results are as follows:

[0124] The hardness of B1 is 505.3HV, the hardness of B2 is 401.2HV, and the hardness of B3 is 315.3HV.

[0125] The hardness of B4 is 240.4HV, the hardness of B5 is 469.7HV, and the hardness of B6 is 420.6HV.

[0126] The hardness of B7 is 344.7HV, the hardness of B8 is 440.3HV, and the hardness of B9 is 340.5HV.

[0127] The hardness of B10 is 321.1HV, the hardness of B11 is 412.8HV, and the hardness of B12 is 297.3HV.

[0128] The hardness of B13 is 251.3HV, the hardness of B14 is 458.4HV, and the hardness of B15 is 338.2HV.

[0129] The hardness of B16 is 286.5HV, the hardness of B17 is 353.8HV, and the hardness of B18 is 307.9HV.

[0130] The hardness of B19 is 234.6HV;

[0131] From the above data, we can see that the metal hardness at the welding center B1 is the highest, with a hardness value of up to 505.3HV; the closer the area is to the welding center B1, the higher the hardness is, because this area undergoes rapid heating and cooling during the welding process, forming fine grains and strengthening phases. As the distance from the welding center B1 increases, the hardness gradually decreases, because the area far away from the welding center B1 is less affected by heat and the organizational structure does not change much.

[0132] like Fig.11 As shown, by scanning electron microscopy Fig.10 The welding center B1 is magnified 10000 times, and it can be clearly observed that the surface flatness of the 304 austenitic stainless steel metal layer 8 covering the copper plate 1 is relatively high, which to some extent indicates that the uniformity of the 304 austenitic stainless steel metal layer 8 is relatively good. Fig.11 It can be seen that the metal particles in the 304 austenitic stainless steel metal layer 8 are spherical in shape. Spherical metal particles usually have good fluidity and filling properties, and can make the 304 austenitic stainless steel metal layer 8 more dense. Fig.10 On the DD section of the welding center B1, the scanning electron microscope is used to magnify it 20 times, as shown in Fig.12 As shown, it can be seen that: there is no gap at the junction of the copper plate 1 and the 304 austenitic stainless steel metal layer 8, and there is no delamination between the copper plate 1 and the 304 austenitic stainless steel metal layer 8, indicating that the bonding between the two is high, so that the 304 austenitic stainless steel metal layer 8 is not easy to fall off from the copper plate 1.

Claims

1. A method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding, characterized in that: The specific steps are as follows: Step 1, first prepare a copper plate (1), a stud welding system and a plurality of 304 austenitic stainless steel studs (7); wherein the stud welding system is composed of a storage type stud welding machine (2) and a stud welding gun (3), which are connected by a cable; the 304 austenitic stainless steel stud (7) is composed of a screw rod (4), a boss (5) and an end block (6) which are arranged in sequence from top to bottom; Step 2, treating the surface of the copper plate (1) to ensure that the surface of the copper plate (1) is smooth and clean, free of impurities and oxide layer, and that the surface roughness Ra of the copper plate (1) is less than 1 mm; Step 3, first set the welding voltage on the energy storage stud welding machine (2) to 44V-45V, then insert the screw (4) of the 304 austenitic stainless steel stud (7) into the chuck of the muzzle of the stud welding gun (3), and then use the stud welding gun (3) to drive the end block (6) of the 304 austenitic stainless steel stud (7) into the interior of the copper plate (1); the stud welding gun (3) is then powered on to ignite the arc, and the end block (6) and the copper plate (1) at the end block (6) are fully melted, and after the molten metal melt is naturally cooled and solidified, the 304 austenitic stainless steel stud (7) is welded to the copper plate (1); then, the boss (5) and the screw (4) of the 304 austenitic stainless steel stud (7) are knocked off, and the solidified 304 austenitic stainless steel metal layer (8) is observed to cover the surface of the copper plate (1), and the single spraying operation is completed; Step 4, determine a new spraying position, spray a new 304 austenitic stainless steel metal layer (8) on the copper plate (1), repeat multiple times, and according to the use requirements, make the 304 austenitic stainless steel metal layer (8) completely or partially cover the surface of the copper plate (1).

2. The method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding according to claim 1, characterized in that: The specific operation steps of step 2 are: 2.1 Finely polish and clean the surface of the copper plate (1) to ensure that the surface of the copper plate (1) is smooth and free of impurities; 2.2 Performing a pickling chemical treatment on the surface of the copper plate (1): first immersing the copper plate (1) in a pickling solution for 1 minute, then rinsing the pickling solution on the copper plate (1) with water, and then blowing the copper plate (1) dry; the pickling solution can remove a portion of the oxide layer on the surface of the copper plate (1); 2.3 Activating the surface of the copper plate (1): coating the surface of the copper plate (1) with a layer of surfactant, and then drying it naturally; the surfactant can completely remove the oxide layer remaining on the surface of the copper plate (1); 2.4 Use a laser focusing microscope to observe the surface roughness of the copper plate (1) to ensure that the surface roughness Ra of the copper plate (1) is less than 1 mm; if the surface roughness Ra of the copper plate (1) is greater than 1 mm, return to step 2.2 to continue processing.

3. The method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding according to claim 2, characterized in that: In 2.2 of step 2, the pickling solution is formed by mixing a nitric acid solution and a hydrofluoric acid solution in a volume ratio of 1:23; wherein the volume molar concentration of the nitric acid solution is 0.1 mol / L, and the mass percentage concentration of the hydrofluoric acid solution is 10%.

4. The method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding according to claim 2, characterized in that: In 2.3 of step 2, the surfactant is a hydrochloric acid solution, and the mass percentage concentration of the hydrochloric acid solution is 10%.

5. The method for spraying 304 austenitic stainless steel on the surface of a copper plate by stud welding according to claim 1, characterized in that: The specific operation steps of step 3 are: 3.1 Use a clamp to hold the copper plate (1); 3.2 Connect the energy storage stud welding machine (2) to the positive pole of the power supply, and connect the copper plate (1) to the negative pole of the power supply; 3.3 Set the welding voltage on the energy storage stud welding machine (2) to 44V-45V; 3.4 Insert the screw rod (4) of the 304 austenitic stainless steel stud (7) into the chuck of the stud welding gun (3), and the boss (5) and the end block (6) of the 304 austenitic stainless steel stud (7) are located outside the stud welding gun (3); 3.5 Point the muzzle of the stud welding gun (3) downward, so that the end block (6) of the 304 austenitic stainless steel stud (7) contacts the copper plate (1), and ensure that the 304 austenitic stainless steel stud (7) and the copper plate (1) remain vertical; 3.6 Press the stud welding gun (3) downward to apply a constant load of 55N to the 304 austenitic stainless steel stud (7) to drive the end block (6) into the copper plate (1); 3.7 The switch of the stud welding gun (3) is triggered, and the stud welding gun (3) is powered on to ignite an arc, so that the end block (6) and the copper plate (1) at the end block (6) are fully melted, and the arc welding lasts for 0.3 seconds; after the molten metal liquid is naturally cooled and solidified, the 304 austenitic stainless steel stud (7) is welded to the copper plate (1); 3.8 Knock off the boss (5) and the screw (4) of the 304 austenitic stainless steel stud (7), and observe that the solidified 304 austenitic stainless steel metal layer (8) covers the surface of the copper plate (1), thus completing the single spraying operation.

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