Stainless steel raw materials are generally divided into:
1. Ferritic stainless steel. Contains 12% to 30% of chromium. Its corrosion resistance, resistance and weldability improve with the addition of chromium content, and the resistance to chloride stress corrosion is better than other stainless steels.
2. Austenitic stainless steel. It contains more than 18% chromium, and also contains about 8% nickel and a few elements such as molybdenum, titanium, and nitrogen. The induction function is good, and it can resist a variety of media corrosion.
3. Austenitic-ferritic duplex stainless steel. It has the advantages of both austenitic and ferritic stainless steels, and has superplasticity.
4. Martensitic stainless steel. High strength, but poor plasticity and weldability.