GB/T 20878-2007 defines stainless steel grades by chemistry and mechanical properties, serving as a reference for standards like GB/T 1220. Key provisions include:
Grade classification: Uses both Chinese designations (e.g., 06Cr19Ni10) and international equivalents (304) for clarity.
Chemical limits: For 304, specifies 18.0–20.0% Cr, 8.0–10.5% Ni, and ≤0.08% C-matching ASTM and EN standards.
Mechanical minima: 304 requires ≥515 MPa tensile strength, ≥205 MPa yield strength, and ≥40% elongation, with hardness ≤201 HB.
Heat treatment: Mandates solution annealing for austenitic grades (1010–1150°C) to dissolve carbides and maximize corrosion resistance.
This standard ensures consistency across Chinese stainless steel production, making it easier for manufacturers to source equivalents of global grades.