Analysis of wire rod direct electroplating with acid copper and subsequent drawing technology
Breakthroughs and Innovations in Welding Wire Technology In recent years, significant progress has been made in the direct electroplating of acid copper on wire and the subsequent drawing technology, marking the beginning of a new chapter in this field. This breakthrough not only demonstrates China's strength in the welding industry, but also heralds a broad prospect for future welding material innovation.
In the high-end technology field of gas shielded welding wire, foreign companies, especially Japanese companies and other industry giants, have long dominated. They firmly occupy the leading position in global technology with their unique "plating before pulling" process, outstanding performance, and stable quality. However, in recent years, leading enterprises in China's welding wire industry have also made unremitting explorations and attempts in this field. Despite the challenges posed by thick wire copper plating and water tank drawing technology, they persisted in innovation and ultimately achieved substantial technological breakthroughs. This significant progress will undoubtedly give China's welding wire industry more say in global competition.
High speed copper plating technology has always played a crucial role in the production process of welding wire. However, with the continuous advancement of industry technology, this traditional technology is gradually facing new challenges. Despite this, the top players in China's welding wire industry have not stopped moving forward. They have delved deeper and continuously innovated, ultimately achieving breakthrough progress in thick wire copper plating and water tank drawing technology. This significant achievement not only demonstrates the strength and potential of China's welding wire industry, but also injects new vitality into the development of global welding material technology.
The quality control of thick wire copper plating is particularly crucial in the process of first plating and then pulling. This is because the semi-finished product after copper plating on the thick wire needs to be drawn in the water tank to become thinner. If the thickness of the semi-finished copper film is insufficient, the thickness of the extended finished copper film will not meet the process requirements. Meanwhile, if the bonding strength between the copper layer and the substrate is not strong enough, the copper layer may not reach the expected thickness due to excessive loss during the water tank drawing process, and may even cause the phenomenon of green wire. Therefore, in the process of first plating and then pulling, it is necessary to ensure that the thickness of the copper film after thick wire copper plating is at least 0.5 μ m or more, and the density and bonding strength of the copper layer should also be able to withstand subsequent pulling operations.
In the traditional plating and pulling process, surface treatment is an indispensable step. It involves a series of processing operations on the semi-finished product after copper plating, aiming to improve the quality, performance, and appearance of the product. These processing measures may include polishing, grinding, chemical treatment, etc., aimed at ensuring that the copper layer has good density, uniformity, and bonding strength to meet the requirements of subsequent drawing operations. Meanwhile, surface treatment can further enhance the corrosion resistance, wear resistance, and overall aesthetics of the product.
A new process of thick wire copper plating and first plating and then pulling. This major breakthrough not only increases the thickness of the semi-finished copper film to 4-5 times that of traditional processes, but more importantly, the density and bonding strength of the copper layer remain unchanged. In addition, the offline speed of the rough copper plating process has reached 10-15m/s, while the wire drawing process of the water tank has been increased to 20m/s. This innovative process breaks the dominant position of foreign enterprises in this field and achieves a significant breakthrough in copper plating technology.
The welding laboratory conducted comprehensive welding tests on the product. The results show that the wire material using the first plating and then pulling process can still maintain stable wire feeding performance without splashing under high current and mixed gas welding processes, and the welding performance is significantly improved. Meanwhile, the testing report from the National Material Service Safety Science Center also confirms that the finished copper layer structure has exceeded the level of cyanide plating in foreign countries, and the surface quality has achieved comprehensive surpassing.
The plating before pulling technique is the first step to
Remove the oxide scale on the surface of the wire rod, and then perform drawing. The wire diameter of the rough drawn wire is generally controlled within
Above Φ 2.0-3.0mm. The metal wire after rough drawing is copper plated, and the semi-finished product after copper plating is further pulled until the finished product is produced.
There are extremely high requirements for the quality of rough copper plating after plating first and then pulling, because the semi-finished products after rough copper plating will be deposited in the water tank
Continue to pull and refine. If the thickness of the semi-finished copper film is low, the thickness of the copper film produced by the extended finished product will not meet the process requirements
Please. If the bonding strength of the copper layer is not good, more copper will be lost during the drawing of the water tank, and the thickness of the finished copper film will also not reach the required level
Even the phenomenon of green hair may occur. Therefore, the process of plating first and then pulling requires that the thickness of the copper film after thick wire copper plating must be controlled at 0.5 μ m
Above, the compactness and bonding strength of the copper layer should also meet the requirements of GB/T8110 1995 or GB/T8110 1987.
The process method for acid copper plating on wire includes the following steps:
(1) Pre treatment of the wire rod, which involves shell stripping, electrolytic acid washing, and descaling to remove iron oxide scale. The specific process is shown below
(2) The specific process for preparing DW-035D copper plating solution is shown below
(a) By using a straight drawing machine, the processed wire rod is subjected to multiple passes of drawing, and the diameter of the wire rod raw material is determined
6.5mm， Pull the water tank to the finished size of mm; perform multiple pulls until it reaches the design diameter.
(b) Pull the raw material with a diameter of 6.5mm from the wire rod to a diameter of 2.0-3.0mm, and then pull the water tank to the finished size
The process of first plating and then pulling formed by precise drawing of water tanks. Avoiding environmental pollution such as waste acid generated by acid washing pretreatment, it can reduce copper consumption more effectively and achieve higher resource utilization compared to pulling before plating. Water tank fine drawing saves more space. Due to the immersion of the water tank drawing machine in the cooling lubricant during the drawing process, the lubrication and cooling conditions of the steel wire are relatively better, effectively improving the surface quality and linearity of the copper plated steel wire. The copper layer adhesion and density of the product have been significantly improved compared to traditional products, which is beneficial for enhancing the anti-corrosion and welding performance of the product. Wet Rabi powder is more friendly to operators, with higher air quality on the production site, reduced wire breakage rate during the production process, and significantly reduced labor intensity for operators
Low.
Electrolytic acid washing process parameters
Technical parameters:
1. Inlet speed: 5-15m/s
2. Rectifiers: 500-1000A 0-20V
3. Electrolytic acid washing process:
Sulfuric acid 180-250g/l DW-100 wire acid salt activator 3-5g/l
Electrolytic current control 30-100A/dm2
Acid pickling solution temperature: room temperature -50 ° C
Time: 10-30 seconds
The electrolytic acid tank adopts a staggered cleaning method of anode and cathode, with stainless steel and lead alloy plates for the electrode rows and a U-shaped groove for the electrode plates. Cover the pole row with insulation mesh to prevent short circuits between the welding wire and the pole row; Add DW-100 wire acid salt activator to the electrolytic pickling tank to accelerate pickling speed and remove surface contaminants from the welding wire.
When passing through the bathtub, the polarity of the wire changes, so it is initially cathodic, then anodic, anodic, and finally cathodic again.
In the cathode stage, hydrogen is discharged on the wire, while in the anode stage, oxygen is discharged, thereby dissolving any oxides and surface impurities.
Compared to traditional acid electrolysis, the cleaning efficiency has increased several times.
Image below: Old style acid washing
Process flow: (1) I-shaped wheel online - electrolytic acid washing - electrolytic acid washing - water washing - direct electroplating of acid copper - drawing
(2) Electrolytic acid pickling - Electrolytic acid pickling - Water washing - Direct electroplating of copper acid - Pulling
Pickling tank 1: 250g/l sulfuric acid DW-100 wire acid salt activator 5g/l
Electrolytic current control 50A/dm2
Acid pickling solution temperature: room temperature -50 ° C
Pickling tank 2: 150g/l sulfuric acid DW-100 wire acid salt activator 5g/l
Electrolytic current control of 30A/dm2
Acid pickling solution temperature: room temperature
The average particle size of copper coating is below 600nm, and the water tank drawing is carried out in the drawing lubrication cooling liquid to ensure that the temperature at the center of the drawing die does not exceed 400 ° C
Copper plating adopts electroplating copper process
Direct electroplating of acid copper has good effect and fast deposition speed
Advantages of direct electroplating of acid copper:
Due to the serious environmental pollution caused by cyanide copper plating on steel wires, it is necessary to conduct pre plating when using cyanide free copper plating. Therefore, researching a cyanide free one-step rapid copper plating process has been the goal pursued by the metal products industry for many years. However, to turn this goal into reality, it is necessary to ensure that the coating produced by the new process meets the technical requirements of good adhesion, fast deposition speed, and fine crystallization of the coating without cyanide copper plating. Only in this way can the cyanide free one-step copper plating process be implemented in the application of steel wire copper plating. However, it is precisely because the current cyanide free copper plating process is not satisfactory in the above aspects, which is also the fundamental reason why the electroplating industry has not completely abandoned cyanide copper plating so far. In recent years, a large amount of research and exploration work has been carried out in the one-step copper plating of steel wire, and several key technologies such as coating adhesion, deposition rate, and coating crystallization state have been tackled, achieving breakthrough progress. ① In terms of the bonding strength of the coating, when the steel wire with a diameter of about 2.0mm plated by the new process is pulled to about 1.0mm and wound by itself, no peeling or scaling of the coating is found, which is higher than the relevant technical standards stipulated by the country (see GB8110-87 standard for the inspection of adhesion of copper plating layer on welding wire in group 4.5 (1)). ② In terms of sedimentation rate, it can fully meet the needs of copper plating on steel wire, and the cathode current density can reach over 15 amps/decimeter ². If other process measures are adopted, the cathode current density can be further increased to meet the technical requirements of high-speed electroplating of steel wire
① The new process combines pre plating and forward plating, greatly simplifying the process flow and reducing the amount of water used for electroplating cleaning; ② The coating obtained by the new process has fine crystallization, good adhesion between the coating and the substrate, and a fast deposition rate; ③ The composition of the new process plating solution is stable, and there is no need to adjust the plating solution frequently. The production process also does not produce "copper powder"; ④ The new process operates at room temperature without the need for ventilation devices, saving energy and equipment investment; ⑤ The new process has a wide range of applications and is suitable for carbon dioxide gas shielded welding wire, copper-clad steel wire, flat wire for packaging, rubber tube steel wire, tire steel wire, etc. (if the steel wire needs to be plated with brass, this process can be used to copper plated and then galvanized on it, and then the brass layer can be obtained by thermal diffusion method); ⑥ The comprehensive production cost of the new process is lower than the current commonly used cyanide free two-step copper plating process for steel wire in China.
The average particle size of the copper coating in the welding wire with added DW-035D high-speed copper plating stabilizer is below 600nm, and the power supply and arc stability are particularly good, improving the adhesion of the copper immersion layer of the steel wire. The H and Fe content in the coating is minimized, and the copper plating layer is dense, especially suitable for low-carbon steel wire copper plating, high-strength welding wire copper plating, and stainless steel wire electrolytic copper plating.
The addition of DW-035D welding wire high-speed copper plating stabilizer can quickly form an electrochemically deposited electroplated copper layer on the steel substrate under the condition of electrification, enabling the rapid formation of a dense copper layer on the surface of the substrate, thereby isolating the direct contact between the acidic plating solution and the substrate, completely stopping the displacement reaction, and ensuring that the copper plating layer has a strong bonding force.
The process of depositing copper film to facilitate wire drawing. It can facilitate the orderly deposition of copper ions, resulting in dense copper deposition and strong adhesion. At the same time, the increase in divalent iron is effectively suppressed, eliminating the trouble of frequent addition of copper sulfate. The film weight of the generated copper film is 2-30g/m2.
The film thickness can be adjusted by adding copper sulfate to increase the thickness and increasing the current to increase the thickness.
CuSO4 ∙ 5H2O: 180-240g/l, optimal 200g/l
H2SO: 30-50g/l 40g/l
Addition amount: DW-035D 2-5 g/l, optimal value 4 g/l
Coating deposition is carried out at a current density of 2-10Adm2
The length of the plating tank determines the thickness of the copper plating layer
Metal coating includes soft metal coated wires or rods that act as solid lubricants during the drawing process. In many cases, wires can be immersed in copper sulfate solution to deposit a copper film as a lubricant. In some types of wires, copper film is left on the wire after final drawing to prevent rusting and facilitate welding.
Surface preparation is crucial. For steel wire production, the harmful substances found on the surface of the wire often use higher oxides (such as iron oxides and magnetic oxides), hydroxides (Rust), as well as foreign impurities (such as dirt particles, lubricant residues, organic matter) or inorganic substances, usually carbonaceous and graphite substances that burn lubricants.
Before electroplating, comprehensive cleaning and surface activation acid washing steps can significantly improve adhesion. These may include mechanical or chemical etching to enhance surface texture and promote bonding. This method uses two-stage sulfuric acid electrolytic cleaning, and changes in acid washing solution and process parameters can accelerate the removal of oxide scale and various pollutants.
Breakthroughs and Innovations in Welding Wire Technology In recent years, significant progress has been made in the direct electroplating of acid copper on wire and the subsequent drawing technology, marking the beginning of a new chapter in this field. This breakthrough not only demonstrates China's strength in the welding industry, but also heralds a broad prospect for future welding material innovation.
In the high-end technology field of gas shielded welding wire, foreign companies, especially Japanese companies and other industry giants, have long dominated. They firmly occupy the leading position in global technology with their unique "plating before pulling" process, outstanding performance, and stable quality. However, in recent years, leading enterprises in China's welding wire industry have also made unremitting explorations and attempts in this field. Despite the challenges posed by thick wire copper plating and water tank drawing technology, they persisted in innovation and ultimately achieved substantial technological breakthroughs. This significant progress will undoubtedly give China's welding wire industry more say in global competition.
High speed copper plating technology has always played a crucial role in the production process of welding wire. However, with the continuous advancement of industry technology, this traditional technology is gradually facing new challenges. Despite this, the top players in China's welding wire industry have not stopped moving forward. They have delved deeper and continuously innovated, ultimately achieving breakthrough progress in thick wire copper plating and water tank drawing technology. This significant achievement not only demonstrates the strength and potential of China's welding wire industry, but also injects new vitality into the development of global welding material technology.
The quality control of thick wire copper plating is particularly crucial in the process of first plating and then pulling. This is because the semi-finished product after copper plating on the thick wire needs to be drawn in the water tank to become thinner. If the thickness of the semi-finished copper film is insufficient, the thickness of the extended finished copper film will not meet the process requirements. Meanwhile, if the bonding strength between the copper layer and the substrate is not strong enough, the copper layer may not reach the expected thickness due to excessive loss during the water tank drawing process, and may even cause the phenomenon of green wire. Therefore, in the process of first plating and then pulling, it is necessary to ensure that the thickness of the copper film after thick wire copper plating is at least 0.5 μ m or more, and the density and bonding strength of the copper layer should also be able to withstand subsequent pulling operations.
In the traditional plating and pulling process, surface treatment is an indispensable step. It involves a series of processing operations on the semi-finished product after copper plating, aiming to improve the quality, performance, and appearance of the product. These processing measures may include polishing, grinding, chemical treatment, etc., aimed at ensuring that the copper layer has good density, uniformity, and bonding strength to meet the requirements of subsequent drawing operations. Meanwhile, surface treatment can further enhance the corrosion resistance, wear resistance, and overall aesthetics of the product.
A new process of thick wire copper plating and first plating and then pulling. This major breakthrough not only increases the thickness of the semi-finished copper film to 4-5 times that of traditional processes, but more importantly, the density and bonding strength of the copper layer remain unchanged. In addition, the offline speed of the rough copper plating process has reached 10-15m/s, while the wire drawing process of the water tank has been increased to 20m/s. This innovative process breaks the dominant position of foreign enterprises in this field and achieves a significant breakthrough in copper plating technology.
The welding laboratory conducted comprehensive welding tests on the product. The results show that the wire material using the first plating and then pulling process can still maintain stable wire feeding performance without splashing under high current and mixed gas welding processes, and the welding performance is significantly improved. Meanwhile, the testing report from the National Material Service Safety Science Center also confirms that the finished copper layer structure has exceeded the level of cyanide plating in foreign countries, and the surface quality has achieved comprehensive surpassing.
The plating before pulling technique is the first step to
Remove the oxide scale on the surface of the wire rod, and then perform drawing. The wire diameter of the rough drawn wire is generally controlled within
Above Φ 2.0-3.0mm. The metal wire after rough drawing is copper plated, and the semi-finished product after copper plating is further pulled until the finished product is produced.
There are extremely high requirements for the quality of rough copper plating after plating first and then pulling, because the semi-finished products after rough copper plating will be deposited in the water tank
Continue to pull and refine. If the thickness of the semi-finished copper film is low, the thickness of the copper film produced by the extended finished product will not meet the process requirements
Please. If the bonding strength of the copper layer is not good, more copper will be lost during the drawing of the water tank, and the thickness of the finished copper film will also not reach the required level
Even the phenomenon of green hair may occur. Therefore, the process of plating first and then pulling requires that the thickness of the copper film after thick wire copper plating must be controlled at 0.5 μ m
Above, the compactness and bonding strength of the copper layer should also meet the requirements of GB/T8110 1995 or GB/T8110 1987.
The process method for acid copper plating on wire includes the following steps:
(1) Pre treatment of the wire rod, which involves shell stripping, electrolytic acid washing, and descaling to remove iron oxide scale. The specific process is shown below
(2) The specific process for preparing DW-035D copper plating solution is shown below
(a) By using a straight drawing machine, the processed wire rod is subjected to multiple passes of drawing, and the diameter of the wire rod raw material is determined
6.5mm， Pull the water tank to the finished size of mm; perform multiple pulls until it reaches the design diameter.
(b) Pull the raw material with a diameter of 6.5mm from the wire rod to a diameter of 2.0-3.0mm, and then pull the water tank to the finished size
The process of first plating and then pulling formed by precise drawing of water tanks. Avoiding environmental pollution such as waste acid generated by acid washing pretreatment, it can reduce copper consumption more effectively and achieve higher resource utilization compared to pulling before plating. Water tank fine drawing saves more space. Due to the immersion of the water tank drawing machine in the cooling lubricant during the drawing process, the lubrication and cooling conditions of the steel wire are relatively better, effectively improving the surface quality and linearity of the copper plated steel wire. The copper layer adhesion and density of the product have been significantly improved compared to traditional products, which is beneficial for enhancing the anti-corrosion and welding performance of the product. Wet Rabi powder is more friendly to operators, with higher air quality on the production site, reduced wire breakage rate during the production process, and significantly reduced labor intensity for operators
Low.
Electrolytic acid washing process parameters
Technical parameters:
1. Inlet speed: 5-15m/s
2. Rectifiers: 500-1000A 0-20V
3. Electrolytic acid washing process:
Sulfuric acid 180-250g/l DW-100 wire acid salt activator 3-5g/l
Electrolytic current control 30-100A/dm2
Acid pickling solution temperature: room temperature -50 ° C
Time: 10-30 seconds
The electrolytic acid tank adopts a staggered cleaning method of anode and cathode, with stainless steel and lead alloy plates for the electrode rows and a U-shaped groove for the electrode plates. Cover the pole row with insulation mesh to prevent short circuits between the welding wire and the pole row; Add DW-100 wire acid salt activator to the electrolytic pickling tank to accelerate pickling speed and remove surface contaminants from the welding wire.
When passing through the bathtub, the polarity of the wire changes, so it is initially cathodic, then anodic, anodic, and finally cathodic again.
In the cathode stage, hydrogen is discharged on the wire, while in the anode stage, oxygen is discharged, thereby dissolving any oxides and surface impurities.
Compared to traditional acid electrolysis, the cleaning efficiency has increased several times.
Image below: Old style acid washing
Process flow: (1) I-shaped wheel online - electrolytic acid washing - electrolytic acid washing - water washing - direct electroplating of acid copper - drawing
(2) Electrolytic acid pickling - Electrolytic acid pickling - Water washing - Direct electroplating of copper acid - Pulling
Pickling tank 1: 250g/l sulfuric acid DW-100 wire acid salt activator 5g/l
Electrolytic current control 50A/dm2
Acid pickling solution temperature: room temperature -50 ° C
Pickling tank 2: 150g/l sulfuric acid DW-100 wire acid salt activator 5g/l
Electrolytic current control of 30A/dm2
Acid pickling solution temperature: room temperature
The average particle size of copper coating is below 600nm, and the water tank drawing is carried out in the drawing lubrication cooling liquid to ensure that the temperature at the center of the drawing die does not exceed 400 ° C
Copper plating adopts electroplating copper process
Direct electroplating of acid copper has good effect and fast deposition speed
Advantages of direct electroplating of acid copper:
Due to the serious environmental pollution caused by cyanide copper plating on steel wires, it is necessary to conduct pre plating when using cyanide free copper plating. Therefore, researching a cyanide free one-step rapid copper plating process has been the goal pursued by the metal products industry for many years. However, to turn this goal into reality, it is necessary to ensure that the coating produced by the new process meets the technical requirements of good adhesion, fast deposition speed, and fine crystallization of the coating without cyanide copper plating. Only in this way can the cyanide free one-step copper plating process be implemented in the application of steel wire copper plating. However, it is precisely because the current cyanide free copper plating process is not satisfactory in the above aspects, which is also the fundamental reason why the electroplating industry has not completely abandoned cyanide copper plating so far. In recent years, a large amount of research and exploration work has been carried out in the one-step copper plating of steel wire, and several key technologies such as coating adhesion, deposition rate, and coating crystallization state have been tackled, achieving breakthrough progress. ① In terms of the bonding strength of the coating, when the steel wire with a diameter of about 2.0mm plated by the new process is pulled to about 1.0mm and wound by itself, no peeling or scaling of the coating is found, which is higher than the relevant technical standards stipulated by the country (see GB8110-87 standard for the inspection of adhesion of copper plating layer on welding wire in group 4.5 (1)). ② In terms of sedimentation rate, it can fully meet the needs of copper plating on steel wire, and the cathode current density can reach over 15 amps/decimeter ². If other process measures are adopted, the cathode current density can be further increased to meet the technical requirements of high-speed electroplating of steel wire
① The new process combines pre plating and forward plating, greatly simplifying the process flow and reducing the amount of water used for electroplating cleaning; ② The coating obtained by the new process has fine crystallization, good adhesion between the coating and the substrate, and a fast deposition rate; ③ The composition of the new process plating solution is stable, and there is no need to adjust the plating solution frequently. The production process also does not produce "copper powder"; ④ The new process operates at room temperature without the need for ventilation devices, saving energy and equipment investment; ⑤ The new process has a wide range of applications and is suitable for carbon dioxide gas shielded welding wire, copper-clad steel wire, flat wire for packaging, rubber tube steel wire, tire steel wire, etc. (if the steel wire needs to be plated with brass, this process can be used to copper plated and then galvanized on it, and then the brass layer can be obtained by thermal diffusion method); ⑥ The comprehensive production cost of the new process is lower than the current commonly used cyanide free two-step copper plating process for steel wire in China.
The average particle size of the copper coating in the welding wire with added DW-035D high-speed copper plating stabilizer is below 600nm, and the power supply and arc stability are particularly good, improving the adhesion of the copper immersion layer of the steel wire. The H and Fe content in the coating is minimized, and the copper plating layer is dense, especially suitable for low-carbon steel wire copper plating, high-strength welding wire copper plating, and stainless steel wire electrolytic copper plating.
The addition of DW-035D welding wire high-speed copper plating stabilizer can quickly form an electrochemically deposited electroplated copper layer on the steel substrate under the condition of electrification, enabling the rapid formation of a dense copper layer on the surface of the substrate, thereby isolating the direct contact between the acidic plating solution and the substrate, completely stopping the displacement reaction, and ensuring that the copper plating layer has a strong bonding force.
The process of depositing copper film to facilitate wire drawing. It can facilitate the orderly deposition of copper ions, resulting in dense copper deposition and strong adhesion. At the same time, the increase in divalent iron is effectively suppressed, eliminating the trouble of frequent addition of copper sulfate. The film weight of the generated copper film is 2-30g/m2.
The film thickness can be adjusted by adding copper sulfate to increase the thickness and increasing the current to increase the thickness.
CuSO4 ∙ 5H2O: 180-240g/l, optimal 200g/l
H2SO: 30-50g/l 40g/l
Addition amount: DW-035D 2-5 g/l, optimal value 4 g/l
Coating deposition is carried out at a current density of 2-10Adm2
The length of the plating tank determines the thickness of the copper plating layer
Metal coating includes soft metal coated wires or rods that act as solid lubricants during the drawing process. In many cases, wires can be immersed in copper sulfate solution to deposit a copper film as a lubricant. In some types of wires, copper film is left on the wire after final drawing to prevent rusting and facilitate welding.
Surface preparation is crucial. For steel wire production, the harmful substances found on the surface of the wire often use higher oxides (such as iron oxides and magnetic oxides), hydroxides (Rust), as well as foreign impurities (such as dirt particles, lubricant residues, organic matter) or inorganic substances, usually carbonaceous and graphite substances that burn lubricants.
Before electroplating, comprehensive cleaning and surface activation acid washing steps can significantly improve adhesion. These may include mechanical or chemical etching to enhance surface texture and promote bonding. This method uses two-stage sulfuric acid electrolytic cleaning, and changes in acid washing solution and process parameters can accelerate the removal of oxide scale and various pollutants.
