GB/T 1220-2007 governs stainless steel round bars in China, covering a wide range of grades (e.g., 304, 316, 430) with comprehensive requirements:
Chemical composition: Strict limits for alloying elements (e.g., 18.0–20.0% Cr and 8.0–10.5% Ni for 06Cr19Ni10/304) to ensure corrosion resistance and mechanical performance.
Mechanical properties: Minimum tensile strength (≥515 MPa for 304), yield strength (≥205 MPa for 304), and elongation (≥40% for 304) to guarantee ductility and strength.
Heat treatment: Specified annealing temperatures (e.g., 1010–1150°C for austenitic grades) to optimize microstructure and corrosion resistance.
Testing: Mandatory chemical analysis, tensile testing, and hardness measurement (≤201 HB for annealed 304). For critical applications, intergranular corrosion testing (per GB/T 4334) is required.
The standard aligns with ISO 15510 and ASTM A276, ensuring Chinese stainless round bars are compatible with global markets. Made-in-China listings often highlight GB/T 1220 compliance for products like "Food-Grade 304 Stainless Round Bar."