GB/T 1220-2007 Stainless Steel Bars – Chinese National Standard

GB/T 1220-2007 Stainless Steel Bars Standard

Standard Number: GB/T 1220-2007

Release Date: May 14, 2007

Implementation Date: December 1, 2007

Replaces: GB/T 1220-1992

Scope

This standard specifies the dimensions, shape, technical requirements, testing methods, acceptance rules, packaging, marking, and quality certificates for stainless steel bars (including round steel, square steel, flat steel, hexagonal steel, and octagonal steel).

This standard applies to hot-rolled and forged stainless steel bars with dimensions (diameter, side length, thickness, or distance across flats) not greater than 250 mm. Stainless steel bars with dimensions greater than 250 mm can also be supplied upon negotiation between supplier and buyer.

Main Changes from 1992 Version

  • Added “Terms and Definitions” and “Ordering Content” (Chapters 3 and 4)
  • Modified “Dimensions, Shape, Weight and Tolerances” to directly reference general basic standards
  • Cancelled 6 old grades and added 6 new grades
  • Adjusted chemical composition of 21 grades according to international standards
  • Modified smelting method – priority to converter molten steel plus secondary refining process
  • Modified delivery state requirements
  • Added surface quality requirements (pickling, turning to remove heat treatment scale)
  • Separated heat treatment systems from mechanical property tables into Appendix A
  • Modified yield strength to mandatory inspection for martensitic and precipitation-hardening stainless steels
  • Corrosion resistance changed to agreement item
  • Specified sampling locations for continuous casting inspection

Product Categories

The standard covers various stainless steel types including:

  • Ferritic stainless steel
  • Austenitic stainless steel
  • Martensitic stainless steel
  • Precipitation-hardening stainless steel
  • Duplex stainless steel

Download Original Standard

The original Chinese national standard document is embedded below for reference.

Note: This is a summary translation of GB/T 1220-2007. For complete technical specifications, please refer to the original document above.