Stainless Steel Bar

Stainless steel is categorized into five primary families distinguished by their crystalline structure:

1. Austenitic: This is the largest family of stainless steels, constituting approximately two-thirds of all stainless steel production. Austenitic stainless steels feature an austenitic microstructure, characterized by a face-centered cubic crystal structure. Austenitic stainless steels cannot be hardened through heat treatment since they retain the same microstructure at all temperatures.

2. Ferritic: Ferritic stainless steels possess a ferrite microstructure similar to carbon steel, featuring a body-centered cubic crystal structure. They typically contain between 10.5% and 27% chromium with minimal or no nickel content.

3. Martensitic: Martensitic stainless steels exhibit a body-centered cubic crystal structure and offer a diverse range of properties. They find application in various fields such as stainless engineering, tool manufacturing, and creep-resistant applications. Martensitic steels are magnetic and generally less corrosion-resistant compared to ferritic and austenitic grades due to their lower chromium content.

4. Duplex: Duplex stainless steels showcase a mixed microstructure comprising both austenite and ferrite, with the ideal ratio being 50:50, though commercial alloys may vary with ratios of 40:60. These steels feature higher chromium (19–32%) and molybdenum (up to 5%) content and lower nickel levels compared to austenitic varieties.

5. Precipitation Hardening: Precipitation hardening stainless steels offer corrosion resistance similar to austenitic grades but can achieve even higher strength levels through precipitation hardening, surpassing other martensitic alloys.