GB/T 1220-2007Stainless steel bars (English PDF)

Foreword

This standard was issued on 14 May 2007 by the General Administration of Quality Supervision, Inspection and Quarantine and the Standardization Administration of the People's Republic of China, and has been in force since 1 December 2007.

It replaces GB/T 1220-1992, Stainless steel bars. Classification: ICS 77.140.20, CCS H 40.

1 Scope

This standard specifies the dimensions, shape, technical requirements, test methods, inspection rules, packing, marks and quality certificate of stainless steel bars - the generic term for round steel, square steel, flat steel, hexagonal steel and octagonal steel, hereinafter referred to as steel bar.

It applies to hot rolled and forged steel bars whose dimension - diameter, side length, thickness or distance across flats - is not more than 250 mm. By agreement between supplier and buyer, hot rolled and forged bars of more than 250 mm may also be supplied.

2 Normative references

The standard cites the GB/T 222 tolerance on chemical composition and the whole GB/T 223 series of chemical analysis methods for iron, steel and alloys, together with the dimensional standards GB/T 702 and GB/T 908, the mechanical test methods and the stainless steel designation standards GB/T 20878 and GB/T 15574. For dated references only the edition cited applies; for undated references the latest edition applies.

3 Terms and definitions

The technical terms and definitions established in GB/T 20878 and GB/T 15574 apply to this standard.

4 Contents in order sheet

A contract or order placed to this standard shall state: a) the standard code; b) the product description; c) the grade or unified numerical code; d) the section shape - round, square, flat, hexagonal or octagonal; e) the dimensions and shape, see Clause 6; f) the weight or quantity; g) the processing method used, see 5.2; h) the delivery state, see 7.2; i) any special requirement, see 7.9.

5 Classification

5.1 By structural features, steel bars are divided into five categories: austenitic, austenitic-ferritic, ferritic, martensitic and precipitation-hardening.

5.2 By application method, steel bars are divided into two categories, which shall be indicated in the contract; failing that, steel for cutting is supplied. Steel for pressing processing (UP): hot pressing processing (UHP), steel for hot forging (UHF), blank for cold drawing (UCD). Steel for cutting processing (UC).

6 Dimension, shape, weight and permissible deviation

The dimensions, shape, weight and permissible deviations of hot rolled round and square steel follow GB/T 702, with the specific requirements to be stated in the contract; the corresponding clauses cover hot rolled flat, hexagonal and octagonal steel and forged bars.

7 Technical requirements

7.1 Grade and chemical composition. 7.2 Melting method. 7.3 Delivery state. 7.4 Mechanical properties. 7.5 Corrosion resistance. 7.6 Macrostructure. 7.7 Hot forging. 7.8 Surface quality. 7.9 Special requirements.