Pickling and passivation is a chemical reaction.

Firstly, the oxide skin and rust on the surface of steel can be removed by pickling solution, and the passivation process is completed at the same time. Can effectively prevent the seamless steel tube oxidation, to achieve the purpose of anti-corrosion. Before pickling and passivation, it is necessary to remove oil, degrease and remove impurities such as surface drawing compounds. The surface of the seamless steel pipe after pickling and passivation becomes uniform silver white, which greatly improves the corrosion resistance of the stainless steel.