1 Scope
This standard prescribes the designation, chemical composition, product analysis variation, mechanical property and sampling location for mechanical property of constructional steel used for forging.
This standard is applicable to general forgings used in equipment of metallurgy, mining, marine accessory and engineering machinery, and these forgings are sampled for determining mechanical property after bulk heat treatment.
Mechanical property specified in this standard is not applicable to forgings of power station equipment such as principal shaft, rotor, impeller and pressure vessel which are twirled at high temperature and high speed.
2. Normative reference
The following standards contain provisions which constitute provisions of this standard through reference in this text. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
l GB 223 Methods for chemical analysis of iron steel and alloy. (Refer to appendix A)
l GB 228 87 Method of metal tensile test
l GB/T 229 94 Metallic materials - Charpy notch impact test
l GB 23l – 84 Metallic materials - Brinell hardness test
l GB 6397 - 86 Metallic materials - Test pieces for tensile testing
3 Designation and chemical compositions
3.1 Designations and chemical compositions (heat analysis) of carbon constructional shall be in accordance with provisions in Table 1.
3.2 Designation and chemical composition (heat analysis) of alloy constructional steel shall be in accordance with provisions in Table 2. Contents of sulfur, phosphorus, remanent copper, chromium and nickel in steel shall be in accordance with the provisions of Table 3.
