Hot-dip galvanized steel coil refers to the semi-finished products after hot rolling, pickling or cold rolling, which are washed, annealed and immersed in molten zinc bath at a temperature of about 460℃ to coat the steel plate with zinc layer, and then tempered, leveled and chemically treated. SGCC material is harder than SECC material, with poor ductility (avoiding deep drawing design), thicker zinc layer and poor weldability. One of the most widely used stainless steels, because it contains Ni (nickel), has better corrosion resistance and heat resistance than steel containing Cr (chromium), and has very good mechanical properties, no heat treatment hardening and no elasticity. The content is lower than SUS304, and the corrosion resistance is poor. However, after cold working, good tensile force and hardness can be obtained during stamping, and the elasticity is good. It is mainly used for leaf springs and is one of the most widely used anti-electromagnetic interference stainless steels. Because it contains Ni (nickel), it has better corrosion resistance and heat resistance than steel containing Cr (chromium), has very good mechanical properties, does not need heat treatment and hardening, and has no elasticity. 5. The content of stainless steel SUS30 1Cr (chromium) is lower than that of SUS304, and its corrosion resistance is poor. However, after cold working, it can obtain good tensile force and hardness and good elasticity when stamping, which is mostly used for leaf springs and EMI prevention.