GB/T 1222-2025Spring Steels (English PDF)

Foreword

This Document was drafted as per the rules specified in GB/T 1.1-2020 Directives for Standardization – Part 1: Rules for the Structure and Drafting of Standardizing Documents.

This Document replaced GB/T 1222-2016 Spring Steels, GB/T 33164.1-2016 Spring Steels for Automotive Suspension System - Part 1: Hot Rolled Spring Steel Flat Bars, and GB/T 33164.2- 2016 Spring Steels for Automotive Suspension System - Part 2: Hot Rolled Round Steel Bar and Wire Rod. This Documents is mainly based on GB/T 1222-2016, integrating the contents of GB/T 33164.1-2016, and GB/T 33164.2-2016. Compared with GB/T 1222-2016, the major technical changes of this Document are as follows besides the structural adjustments and editorial modifications:

a) Change the scope of application of the standard (see Clause 1 of this Edition; Clause 1 of b) Change the ordering contents (see Clause 4 of this Edition; Clause 4 of the 2016 Edition);

c) Change the requirements for copper content and silicon content in 60Si2Mn (see 6.1.1 of d) Add grouping by phosphorus and sulfur contents (see 6.1.2 of this Edition);

e) Change the oxygen content requirements in alloy spring steel (or billets) (see 6.1.3 of this f) Delete the 40SiMnVBE designation and its related requirements (see Clause 6 of the 2016 Edition);

g) Change the mechanical property requirements for 60Si2Mn (see 6.3 of this Edition; 6.4 h) Add hardenability requirements for 60CrMnB (see 6.4 of this Edition);

i) Change the requirements for low magnification (see 6.5 of this Edition; 6.6 of the 2016 Edition);

j) Change the requirements for non-metallic inclusions (see 6.6 of this Edition; 6.7 of the k) Change the requirements for decarburized layers (see 6.7 of this Edition; 6.8 of the 2016 Edition);

l) Add grain size requirements (see 6.8 of this Edition);

m) Change the surface quality requirements (see 6.9 of this Edition; 6.9 of the 2016 Edition);

Please note some contents of this Document may involve patents. The issuing agency of this Document shall not assume the responsibility to identify these patents.

This Document was proposed by China Iron and Steel Association.

This Document shall be under the jurisdiction of National Technical Committee on Steels of Standardization Administration of China (SAC/TC 183).

Drafting organizations of this Document: Jiangyin Xingcheng Special Steel Works Co., Ltd.; Fangda Special Steel Technology Co., Ltd.; Daye Special Steel Co., Ltd.; Qingdao Special Steel Co., Ltd.; Jiangsu Yonggang Group Co., Ltd.; China National Heavy Duty Truck Group Co., Ltd.; Hunan Valin Xiangtan Iron & Steel Co., Ltd.; Nanjing Iron and Steel Co., Ltd.; Shougang Group Co., Ltd.; Fushun Special Steel Co., Ltd.; China Metallurgical Information and Standardization Institute; Jiangsu Lihuai Iron & Steel Co., Ltd.; Lingyuan Iron & Steel Co., Ltd.; Linyi Iron & Steel Investment Group Special Steel Co., Ltd.; and Zhejiang Gold Intelligent Suspension Co., Ltd.

Chief drafting staffs of this Document: Bai Yun, Li Wei, Liang Jianguo, Shi Xiaofeng, Ge Longgui, Chen Yuanqing, Ji Wei, Jia Jin, Zheng Hongwei, Li Tao, Chao Yuelin, Meng Yu, Yan Chengming, Zhang Qibin, Bao Yukun, Jiang Zhensheng, Li Pengchao, Wu Junjie, Wu Zheng, Zhu Shuai, Chen Ming, Zhang Ming, Gu Jie, Xiao Chao, Wang Xuyi, Shen Puheng, Gong Cui, Li Runxia, Lu Qiang, Wang Xinhe, Xu Zhengzhou, Zhao Zhi, Xie Hongchao, and Xie Shangpu.

The historical editions replaced by this Document are as follows:

--- GB/T 1222 was first-time published in 1975; first-time revised in 1984; second-time

revised in 2007; and third-time revised in 2016;

--- It is fourth-time revised hereby, integrating the contents of GB/T 33164.1-2016 Spring Steels for Automotive Suspension System - Part 1: Hot Rolled Spring Steel Flat Bars, and GB/T 33164.2-2016 Spring Steels for Automotive Suspension System - Part 2: Hot Rolled Round Steel Bar and Wire Rod.

1 Scope

This Document specifies the ordering contents, manufacturing processes, technical requirements, test methods, inspection rules, packaging, marking, and quality certificate for spring steels.

This Document applies to round and square spring steel bars with a nominal diameter or side length no more than 180 mm; flat spring steel bars with a nominal width no more than 180 mm and a nominal thickness no more than 70 mm; and spring steel wire rods with a nominal diameter no more than 40 mm (hereinafter collectively referred to as steels). The designations and chemical compositions of steel ingots, billets, and their products shall be followed accordingly.

2 Normative References

The provisions in following documents become the essential provisions of this Document through reference in this Document. For the dated documents, only the versions with the dates indicated are applicable to this Document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 5216-2014 Structural steel with specified hardenability bands GB/T 6394 Determination of estimating the average grain size of metal GB/T 7736 Ultrasonic inspecting method for macro-structure and imperfection of steel GB/T 8170-2008 Rules of rounding off for numerical values & expression and judgement of limiting values GB/T 10561-2023 Determination of content of nonmetallic inclusions in steel - Micrographic method using standard diagrams GB/T 11261 Steel and iron - Determination of oxygen content - The pulse heating inert gas fusion-infra-red absorption method GB/T 13298 Inspection methods of microstructure for metals GB/T 13299 Determination of free cementite, pearlite and Widmanstaten structure in steel GB/T 14981-2009 Dimension，shape，mass and tolerance for hot-rolled round wire rod GB/T 17505 Steel and steel products - General technical delivery requirements GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method) GB/T 37566 Method of ultrasonic testing for round steel YB/T 4413 Metallographic determination of core segregation in high carbon steel wire rod

3 Terms and Definitions

4 Ordering Contents

Contracts or orders placed in accordance with this Document should include the following information:

c) Designation or Uniform Numerical Code;

g) Mechanical properties (tempering temperature of 60Si2Mn);

k) Decarburized layer (grouping of hot-rolled materials);

l) Application (e.g., for automotive suspension systems);

5 Manufacturing Process

6 Technical Requirements

7 Test Methods

7.1 Chemical composition analysis of steel shall be conducted according to GB/T 223 (all parts), GB/T 4336, GB/T 20123, or generally accepted methods. The specific method to be determined through negotiation between the supplier and the purchaser shall apply in arbitration.

1 Chemical composition 1 piece/furnace GB/T 20066 See 7.1 Any piece (coil) of steel (billet), at half radius steel Acid etching 2 pieces/batch Ingot casting:

8 Inspection Rules

9 Packaging, Marking, and Quality Certificate

The packaging, marking, and quality certificate of steel shall comply with the provisions of GB/T 2101.

Appendix A Main Uses of Each Designation

The main uses of each designation in this Document are shown in Table A.1. 65, 70, 80, 85 It has a wide range of applications, but is mostly used to manufacture small springs with low operating temperatures; larger springs for general purposes; and springs for general machinery It is used to manufacture various small-section flat springs, coil springs, and clock springs; and can also be used to manufacture spring rings, valve springs, shock absorber and clutch springs, brake springs, etc. 55CrMn, 60CrMn It is used in the manufacture of automotive stabilizer bars; and for producing larger leaf springs and coil springs 60CrMnB It is suitable for manufacturing thicker leaf springs, automotive guide arms, and other products 60CrMnMo The extra-large springs used in the manufacture of large civil engineering projects, heavy-duty vehicles, machinery, etc. 28SiMnB It is used in the manufacture of automotive leaf springs 38Si2 Spring clips used in the manufacture of rail fasteners 55SiMnVB It is used for manufacturing leaf springs for heavy, medium, and small automobiles; also suitable for manufacturing other medium-sized leaf springs and coil springs 56Si2MnCr It is generally used for making suspension springs from cold-drawn steel wire and quenched and It is widely used, primarily manufacturing various springs, such as leaf springs and coil springs for automobiles, locomotives, and tractors; general-purposed springs for automobile stabilizer bars, and low-stress truck bogie; and spring clips for rail fasteners 52Si2CrMnNi Chromium-silicon-manganese-nickel steel is used to manufacture large-size stabilizer bars for heavy-duty trucks 55SiCr It is used for manufacturing coil springs and valve springs for automotive suspension 60Si2Cr It is mostly used in the manufacture of important springs with high loads, such as springs for engineering machinery, etc. […]

Appendix B Comparison List of Designations in this Document with

Table B.1 shows the comparison list of designations in this Document with those in previous editions and domestic/international standards.

Appendix C Main Technical Parameters of 28SiMnB Steel

The critical points and elastic modulus of 28SiMnB steel are shown in Tables C.1 and C.2.

Appendix D Hardenability Bands for Some Designations

Hardenability (H band) for some designations is shown in Table D.1; hardenability (HH band) is shown in Table D.2.

Appendix E Cross-sectional Shape, Nominal Dimensions and Appearance