304 Stainless Steel Chemical Composition & Mechanical Properties

1. What role does chromium play in 304 stainless steel? Chromium forms a dense protective oxide layer on the surface, enhancing oxidation and general corrosion resistance.

2. Why is nickel added to 304? Nickel stabilizes the austenitic structure, improving ductility, toughness, and weldability.

3. What is the hardness of 304 stainless steel? Brinell hardness ≤201 HB in the annealed state, which can be increased by cold working.

4. Does 304 stainless steel contain molybdenum? No, unlike 316, 304 does not contain molybdenum, which limits its chloride corrosion resistance.

5. How does cold working affect 304's mechanical properties? Cold working increases tensile strength and hardness but reduces ductility, which can be restored by annealing.