GB/T 13304.2-2008 in English

《GB/T 13304.2-2008钢分类 第2部分：按主要质量等级和主要性能或使用特性的分类》由TC183（全国钢标准化技术委员会）归口，TC183SC2（全国钢标准化技术委员会基础分会）执行，主管部门为中国钢铁工业协会。
GB/T 13304《钢分类》分为两个部分，本部分为GB/T 13304《钢分类》的第2部分。
本标准代替GB/T 13304-1991《钢分类》中的第二部分。
本部分规定了非合金钢、低合金钢和合金钢按主要质量等级和主要性能或使用特性分类的基本原则和要求。
本部分适用于按主要质量等级和主要性能或使用特性对非合金钢、低合金钢和合金钢进行分类。
本部分与GB/T 13304-1991中的第二部分相比主要变化如下：
―――将“规范性引用文件”中的标准作为附录Ａ（1991年版第2章，本版附录A）；
―――增加“术语及定义”（见第3章）；
―――钢分类按“概述”、“定义”和“举例”编写（1991年版第3、4、5章，本版第4、5、6章）；
―――更新并补充了规范性引用文件（见第2章）；
―――更新、删除、增补了钢分类的举例（见表1、表2、表3）；
―――删除了钢分类举例，改为引用表1、表2和表3（1991年版3.1.1.2、3.1.2.2、3.1.3.2、4.1.1.2、4.1.2.2、4.1.3.2、5.1.2.2）；
―――“普通质量非合金钢”和“普通质量低合金钢”定义中“硫或磷含量最高值”由大于０．０４５％调整为0.040%（1991年版3.1.1.1c）和4.1.1.1c），本版4.1.1.2c）和5.1.1.2c））；
―――“特殊质量低合金钢”定义中增加了f）~g）要求（1991年版4.1.3.1，本版5.1.3.2）；
―――“优质合金钢”定义中修改了a）、c）、e）规定，增加g）规定（1991年版5.1.3.2，本版6.1.1.2）；
―――增加了“按主要性能及使用特性分类”的准则（见4.2.1、5.2.1、6.2.1）；
―――增加了本部分与ISO 4948-2：1981标准的技术性差异及其原因（见附录B）

1 Scope
This part specifies fundamental principles and requirements of classification for non-alloy steel, low-alloy steel and alloy steel according to main quality class and main property or application characteristics.
This part is applicable to classification of non-alloy steel, low-alloy steel and alloy steel according to main quality class and main property or application characteristics.
2 Normative References
Provisions of the following documents constitute some provisions of this part of GB/T 13304 through reference. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties whose enter into agreement according to these specifications are encouraged to research whether the latest editions of these labels are applied or not. For undated references, the latest editions of the normative documents are applicable to this part.
See Appendix A.
3 Terms and Definitions
For the purpose of this part, the following terms and definitions apply.
4 General Classification Of Non-alloy Steels
The general classification of non-alloy steels is as:
A) Classification according to main quality class of steel (see 4.1);
B) Classification according to main property or application characteristics of steel (see 4.2)
4.1 Classification according to main quality class
Non-alloy steels are classified according to the main quality class as:
A) Common-quality non-alloy steel (see 4.1.1);
B) Good-quality non-alloy steel (see 4.1.2);
C) Special-quality non-alloy steel (see 4.1.3).
4.1.1 Common-quality non-alloy steel
4.1.1.1 Brief
Common-quality non-alloy steel refers to steel that no special control quality requirement is specified in manufacturing process.
4.1.1.2 Definition
The steels that satisfy all the following conditions are common-quality non-alloy steels.
A) The steel is non-alloying one (meeting the requirements in the content limits of alloying elements in non-alloy steel specified by Part 1 of this standard);
B) Not specified in heat treatment;
Note: annealing, normalizing, stress relieving and softening treatment are not regarded as heat treatment.
C) If the product standard or the technical specifications specifies, the characteristic value hereof shall meet the following conditions:

1 Scope
2 Normative References
3 Terms and Definitions
4 General Classification Of Non-alloy Steels
5 General Classification of Low-alloy Steel
6 General Classification of Alloy Steel
Appendix A (Normative) Normative References
Appendix B (Informative) Technical Difference and Its Reasons of This Part and ISO 4948-2: 1981