Why Does Stainless Steel Casting Parts Have Rust Resistance And Corrosion Resistance?

Stainless steel has the ability to resist oxidation, known as stainless steel casting parts rust resistance, as well as the ability to withstand corrosion in acidic, alkaline, and saline environments, this is corrosion resistance. The corrosion resistance of stainless steel depends on the chromium content. When the amount of chromium added reaches 12.5%, its resistance to atmospheric corrosion significantly increases. In oxidizing media, chromium enables the steel surface to quickly form a corrosion-resistant and insoluble chromium-rich oxide film that is dense and firmly adheres to the metal. This tightly adhered chromium oxide can protect the surface and prevent further oxidation. If the surface is damaged, the exposed steel surface will react with the atmosphere and undergo self-repair, re-forming this "passive film" to continue its protective function. This oxide layer is extremely thin, allowing the natural luster of the steel surface to be seen through it, giving stainless steel its unique appearance. Additionally, chromium can effectively increase the electrode potential of the steel.

 When the chromium content is not less than 12.5%, it can cause a sudden change in the electrode potential of the steel, shifting from a negative potential to a positive potential, significantly improving the corrosion resistance of the steel. The higher the chromium content, the better the corrosion resistance of the steel. When the chromium content reaches 25% or 37.5%, a second and third change occurs, resulting in even higher corrosion resistance for the steel.