Performance analysis of stainless steel square tube

Metals can react with oxygen in the atmosphere to form an oxide film on the surface. The iron oxide formed on ordinary carbon steel will continue to oxidize, causing corrosion to continue to expand and eventually form holes. This can use paint or oxidation-resistant metal plating to protect the surface of carbon steel, but this protective layer is only a thin film. If the protective layer is destroyed, the steel below will begin to rust again. Whether the stainless steel pipe is rusted is related to the chromium content in the steel. When the chromium content in the steel reaches 12%, in the atmosphere, a layer of passivated, dense chromium-rich oxide is generated on the surface of the stainless steel pipe to protect the surface and prevent Further re-oxidation. This kind of extremely thin oxide layer, and the natural luster of the steel surface can be seen through it, giving the stainless steel a unique surface. If the chromium film is once damaged, the chromium in the steel and the oxygen in the atmosphere will regenerate a passivation film to continue to play a protective role. In some special environments, stainless steel will also fail due to some local corrosion, but stainless steel, unlike carbon steel, will not fail due to uniform corrosion, so the corrosion allowance is meaningless for stainless steel pipes.