Austenitic stainless steel has good corrosion resistance and high temperature oxidation resistance, and its main purpose is to prevent corrosion and rust. The corrosion resistance of stainless steel mainly depends on the surface passivation film. If the film is incomplete or defective, the stainless steel will still be corroded.

Mechanical polishing-In addition to making stainless steel look beautiful and generous, the surface treatment of stainless steel has another purpose more importantly. The main reason why stainless steel does not rust is that this metal is an alloy. The molecules of this metal are not active. It is not easy to chemically react with air. But not only the stainless steel is 100% resistant to rust. It depends on how and where it is used.

After the stainless steel is polished mechanically, a protective film is formed on the stainless steel surface by pressing the stainless steel surface. This kind of membrane better isolates the chemical reactions caused by water, air and other molecules. Make the surface molecules of stainless steel tighter and firmer. Enhance the corrosion resistance of stainless steel. Improve the service life of stainless steel.

Pickling passivation--Acid pickling passivation is usually carried out in engineering, so that the corrosion resistance of stainless steel can be brought into full play. In the process of forming, assembling, welding and welding seam inspection (such as flaw detection, pressure test) and construction marking of stainless steel equipment and components, surface oil stains, rust, non-metallic dirt, low-melting metal contaminants, paint, and welding slag are brought about These substances affect the surface quality of stainless steel equipment and components, destroy the oxide film on the surface, reduce the overall corrosion resistance and local corrosion resistance of the steel (including pitting corrosion, crevice corrosion), and even cause stress Corrosion cracking

Stainless steel surface cleaning, pickling and passivation, in addition to maximizing corrosion resistance, also prevent product contamination and obtain beautiful appearance

The stainless steel workpiece will form an oxide film when placed in the air, but the protection of this film is not perfect. Usually, thorough cleaning, including alkali cleaning and acid cleaning, and then passivation with an oxidant is required to ensure the integrity and stability of the passivation film. One of the purposes of pickling is to create favorable conditions for passivation treatment to ensure the formation of a high-quality passivation film.