2.5 Galvanized Square Tubing

Metals can react with oxygen in the atmosphere to form an oxide film on the surface, and the iron oxide formed on ordinary carbon steel will continue to oxidize, causing the rust 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 damaged, the steel below will start to rust again. Whether the stainless steel pipe is corroded 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 and dense chromium-rich oxide is formed on the surface of the stainless steel pipe to protect the surface and prevent corrosion. further reoxidation. This kind of oxide layer is extremely thin, and the natural luster of the steel surface can be seen through it, making the stainless steel have a unique surface. If the chromium film is 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 unlike carbon steel, stainless steel will not fail due to uniform corrosion, so the corrosion allowance is meaningless for stainless steel pipes