Stainless Steel Sheet Metal Fabrication

Stainless steel is not a specific type of material; it’s a general term. Typically, stainless steel contains iron and at least 10.5% chromium. Different grades of stainless steel contain different proportions of alloying elements. From a mechanical property perspective, it can be divided into the following four grades:

1. Austenitic Stainless Steel

Austenitic stainless steel is the most widely used and the most common among various stainless steel materials. It contains 16-25% chromium and nickel. In addition, it sometimes contains dissolved nitrogen. Austenitic stainless steel is non-magnetic and exhibits good properties in terms of ductility, formability, and weldability.

2. Ferritic Stainless Steel

Unlike austenitic stainless steel, ferritic stainless steel is inherently magnetic. This magnetic stainless steel does not contain nickel and cannot be heat-treated. It possesses stable corrosion resistance and oxidation resistance, but its ductility, yield strength, and work hardening capacity are relatively low. Common ferritic stainless steel products include sinks and exhaust pipes.

3. Duplex Stainless Steel

Duplex stainless steel contains nickel, molybdenum, and more than 20% chromium. Duplex stainless steel combines the microstructures of ferritic and austenitic stainless steel, thus possessing superior corrosion resistance, good wear resistance, and relatively good weldability. Furthermore, it boasts a high energy-absorption capacity and mechanical strength. Its applications are wide-ranging, including bridges, water heaters, seawater systems, and storage tanks.

4. Martensitic Stainless Steel

Martensitic stainless steel has a relatively high carbon content, while its chromium content is typically between 12% and 18%. It can be heat-treated and hardened through forging and quenching. Supermartensitic stainless steel is a modern type of stainless steel with even better corrosion resistance and higher strength.