Q:What is SUS304 material?

SUS304 is an austenitic stainless steel according to the Japanese Industrial Standard (JIS), corresponding to the American ASTM standard 304 stainless steel (UNS S30400) and the Chinese national standard 06Cr19Ni10.

1. The chemical composition of SUS304 is characterized by low carbon and high chromium and nickel content, specifically:
Carbon (C): ≤0.08%
Chromium (Cr): 17.00-19.00%
Nickel (Ni): 8.00-10.50%
Manganese (Mn): ≤2.00%
Silicon (Si): ≤1.00%
Phosphorus (P): ≤0.045%
Sulfur (S): ≤0.030%.

2. Key elements and their roles:
Chromium: Forms a dense chromium oxide (Cr₂O₃) protective film, resisting oxidation and corrosion.

Nickel: Stabilizes the austenitic structure, improving low-temperature toughness and acid and alkali resistance.

Low-carbon design: Reduces intergranular corrosion tendency and optimizes weldability.

3. Physical Properties
Density: 7.93 g/cm³
Melting point: 1398-1454°C
Thermal conductivity: 16.3 W/(m·K) (at 100°C)
Coefficient of thermal expansion: 17.2×10⁻⁶/°C (0-100°C)
Resistivity: 0.73×10⁻⁶Ω·m (at 20°C)
Magnetic properties: Non-magnetic (annealed state), may develop weak magnetism after cold working.

4. Mechanical Properties
SUS304 in the annealed state exhibits the following typical mechanical properties:
Tensile strength (σb): 520-1035 MPa
Yield strength (σ0.2): ≥205 MPa
Elongation (δ5): ≥40%
Hardness: ≤187 HB (Britner hardness)
Impact toughness: Excellent low-temperature toughness (maintains good ductility even at -196°C).
Work hardening characteristics: Cold working can significantly improve strength (e.g., hardness can reach HRB 92 after cold rolling).

Time：03/04/2026 11:37:16