According to its structure, stainless steel can be divided into austenitic stainless steel, ferritic stainless steel, duplex stainless steel, martensitic stainless steel and precipitation hardening stainless steel.

1、 Austenitic stainless steel

Austenitic stainless steel is an important type of stainless steel, accounting for 70% of the total production and usage of stainless steel. According to the alloying method, austenitic stainless steel can be divided into two categories: chromium nickel steel and iron chromium manganese steel. The former uses nickel as the austenitizing element, which is the main body of austenitic steel; The latter is a nickel saving steel grade that replaces expensive nickel with manganese and nitrogen.

Overall, austenitic steel has good corrosion resistance, comprehensive mechanical and process properties, but its strength and hardness are relatively low.

2、 Ferritic stainless steel

Ferritic stainless steel contains 11% -30% chromium and basically does not contain nickel. It is a nickel saving steel type, and its microstructure is mainly ferrite in use.

Ferritic stainless steel has high strength, but low cold work hardening tendency. It has good resistance to chloride stress corrosion, pitting corrosion, crevice corrosion and other local corrosion properties, but is sensitive to intergranular corrosion and poor low-temperature toughness.

3、 Duplex stainless steel

It is generally believed that austenite+ferrite duplex stainless steel can be called if there is more than 15% ferrite on the austenite matrix or more than 15% austenite on the ferrite matrix.

Duplex stainless steel has the advantages of both austenitic and ferritic steels.

4、 Martensitic stainless steel

Martensitic stainless steel is a kind of steel whose properties can be adjusted by means of heat treatment, with high strength and hardness.

5、 Precipitation Hardening Stainless Steel

Precipitation hardening stainless steel is a steel that uses heat treatment to precipitate carbides in the steel, thereby achieving the goal of improving strength.