In this article, Baowu will show you why stainless steel is corrosion-resistant.
However, from the definition of stainless steel, stainless steel is steel that is not easy to rust. In fact, some stainless steels have both rust resistance and acid resistance. Stainless steel materials include: stainless steel strip, stainless steel rod, stainless steel plate, stainless steel wire, stainless steel tube, etc. 202, 201, etc.
Stainless steel is widely used in all walks of life because of its corrosion resistance, so why does stainless steel have corrosion resistance?
All metals react with oxygen in the atmosphere to form an oxide film on the surface. Unfortunately, the iron oxide that forms on ordinary carbon steel continues to oxidize, allowing the rust to expand and eventually form holes. Carbon steel surfaces can be secured by plating with paint or oxidation-resistant metal, but, as is known, this protection is only a thin film. If the protective layer is damaged, the underlying steel begins to corrode.
The corrosion resistance of stainless steel depends on chromium, but because chromium is one of the components of steel, protection methods vary.
When the addition amount of chromium reaches 10.5%, the atmospheric corrosion resistance of steel increases significantly, but when the chromium content is higher, although the corrosion resistance can still be improved, it is not obvious. The reason is that alloying steel with chromium changes the type of surface oxide to a surface oxide similar to that formed on pure chromium metal. This tightly adhering chromium-rich oxide protects the surface from further oxidation. This oxide layer is extremely thin, through which the natural luster of the steel surface can be seen, giving stainless steel a unique surface. Moreover, if the surface layer is damaged, the exposed steel surface will react with the atmosphere to repair itself, re-form this "passivation film", and continue to play a protective role.
Therefore, all stainless steels have a common characteristic, that is, the cadmium content is above 10.5%.
Therefore, the above is the reason why stainless steel has corrosion resistance properties. If you want to know more, please feel free to follow Baowu.
