Production Method of Electro-galvanized Steel Sheets with High Anti-blackening Property
Introduction
Electro-galvanizing steel is a kind of hot-dip galvanized steel, which can obtain high performance of anti-blackening rusting after surface treatment. It is widely used in the production of automobile parts, household appliances and other household products. The high mechanical strength and excellent corrosion resistance of electro-galvanizing steel make it an ideal material for making high-end products. In this paper, we will introduce the production method of electro-galvanized steel sheets with high anti-blackening property, including the pre-treatment of the steel sheet, the electro-galvanizing process, the surface treatment process, etc.
Pre-treatment of Steel Sheet
Before the electro-galvanizing process, the pre-treatment is the key step to ensure its surface quality. In order to make the steel sheet reach the expected performance, the pre-treatment process must be carried out correctly.
Firstly, the steel sheet needs to be pickled and degreased in acid bath to produce clean surface for the subsequent process. The pickling process mainly uses sulfuric acid to clean the surface of the steel sheet, which can remove the rust, oxide and grease on the surface of the steel sheet. Secondly, the steel sheet needs to be washed and neutralized in water bath to remove the residual acid on the surface of the steel sheet.
Thirdly, the steel sheet needs to undergo phosphating process, which can provide good adhesion of the electro-galvanizing layer and effectively increasing the anti-corrosion capacity.
Last but not the least, the steel sheet needs to be passivated in acid bath to increase its thickness and enhance the brightness, which can make the steel sheet more beautiful and attractive.
Electro-Galvanizing Process
After the pre-treatment process, the steel sheet is ready for the electro-galvanizing process. In this process, the steel sheets are immersed into the electro-galvanizing solution to form a layer of zinc-based on the surface. The electro-galvanizing solution is composed of zinc chloride, zinc sulfate and other additives, which can make the electro-galvanizing layer more uniform and smooth.
The electro-galvanizing process can be divided into two parts, the anode and cathode process. In the anode process, the steel sheet is placed in a container filled with a certain amount of electro-galvanizing solution. The anode is connected to the positive pole of the power and the steel sheet is connected to the negative pole, so that zinc ions are released from the anode and deposited on the surface of the steel sheet. In the cathode process, the steel sheet is placed in the same container, and the cathode is connected to the negative pole, so that the zinc ions on the steel sheet will be returned to the anode. This process can form an evenly and smooth electro-galvanizing layer on the surface of the steel sheet.
Surface Treatment Process
After the electro-galvanizing process, the steel sheet needs to be treated on the surface to achieve the excellent anti-blackening performance. Firstly, the steel sheet needs to be passivated to increase its corrosion resistance. Passivation can make the steel sheet be exposed to the air and create a thin, transparent film on the surface of the steel sheet to protect the inner layer.
Secondly, chromates treat is needed to increase the adhesion of the protective film and prevent any corrosion of the steel sheet. The chromates solution is added to the steel sheet to form a good adhesion of the protective film and effectively increase the life of the steel sheet.
Thirdly, the coating of organic protective film is also an important step to optimize the steel sheet’s anti-blackening performance. This process can make the electro-galvanizing layer be smooth and uniform, which can effectively increase the duration of the anti-blackening performance.
Conclusion
In conclusion, electro-galvanized steel sheets with high anti-blackening performance have a wide range of application and are widely used in various fields. In this paper, we introduce the production process of electro-galvanizing steel sheets with high anti-blackening property, including the pre-treatment of the steel sheet, the electro-galvanizing process and the surface treatment process. Through the correct and efficient production process, the electro-galvanized steel sheets with high anti-blackening performance can be obtained, which can provide good corrosion resistance and extend the service life.
