The passivation process of carbon steel tees can be divided into many types, and they are commonly divided into two types: wet method and dry method. The iron oxide formed on the ordinary carbon steel continues to oxidize, causing the corrosion to continue to expand, and finally to form holes. It is possible to use paint or oxidation-resistant metals (such as zinc, nickel and chromium) for electroplating to ensure the surface of carbon steel, but, as people know, this protection is only a thin film. If the protective layer is damaged, the steel underneath will begin to rust.

     The passivation effect of carbon steel tee depends on both the passivation process and the material of the stainless steel stamping elbow. The specific influencing factors include the elements contained in the stainless steel stamping elbow, the stainless steel metallographic structure, and the processing state of the stainless steel, etc. . Among the constituent elements, chromium and nickel are elements with strong passivation properties, followed by the passivation properties of iron. Therefore, the higher the content of chromium and nickel, the stronger the passivation properties of stainless steel.

　　Austenitic and ferritic stainless steel stamping elbows have a relatively uniform structure and good passivation. Martensitic stainless steel is strengthened by heat treatment, and its metallographic structure is multi-phase structure, so the passivation is not strong. The smooth and clean surface of carbon steel tee after mechanical processing has better passivation, and the surface of the workpiece obtained by casting and sandblasting is rough, which is not conducive to passivation. Carbon steel tee will not produce corrosion, pitting, rust or wear. Stainless steel is also one of the strongest materials among the metal materials used in construction.