GB/T 9945-2025Hot-rolled bulb flats (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part 1: Structure and drafting rules for standardization documents" Drafting is required.

This document replaces GB/T 9945-2012 Hot-rolled bulb flat steel. Compared with GB/T 9945-2012, except for structural adjustments and editorial changes, In addition to the dynamic, the main technical changes are as follows.

--The scope of application has been changed (see Chapter 1, Chapter 1 of the 2012 edition);

--Added bulb flat steel models (see Table 1);

--The theoretical weight of bulb flat steel has been changed (see Table 1 of the 2012 edition);

--Changed the normal length requirements for bulb flat steel (see 5.1.2, 4.1.2 of the 2012 edition);

--Changed the curvature requirements (see 5.2.1, 4.2.1 of the 2012 edition);

--Added requirements for end burrs (see 5.2.3);

--Added requirements for ball head bending deformation (see 5.2.4);

--Changed the weight tolerance of bulb flat steel (see 5.3, 4.3 of the 2012 edition);

--Changed the values of grain-refining element combinations in the chemical composition of high-strength bulb flat steel (see Table 3, 2012 edition) Table 3);

--Changed the surface quality requirements (see 6.5, 5.5 of the 2012 edition);

--The batching rules have been changed (see 8.2, see 7.2 of the 2012 edition).

Please note that some of the contents of this document may involve patents. The issuing organization of this document does not assume the responsibility for identifying patents.

This document was proposed by the China Iron and Steel Association.

This document is under the jurisdiction of the National Technical Committee on Steel Standardization (SAC/TC 183).

This document was drafted by: Changshu Longteng Special Steel Co., Ltd., Taixing Jufeng Rolling Technology Co., Ltd., Suqian Nangang Jinxin Steel Rolling Co., Ltd., Anshan Zizhu Light Special Steel Co., Ltd., and Metallurgical Industry Information Standards Research Institute.

The main drafters of this document are: Ji Bingyuan, Xu Sheng, Zhao Xun, Li Chunshan, Wu Jiajun, Liu Baoshi, Pu Hongbing, Jiang Kun, Liu Junjun, Hong Ze, Wang Yujie, Ma Liang, Xu Haochi, and Zhou Jun.

The previous versions of this document and the documents it replaces are as follows.

--First published as GB/T 9945-1988 in 1988, first revised in 2001, and second revised in 2012; --This is the third revision. Hot rolled bulb flat steel

1 Scope

This document specifies the order content, model, size, shape, weight and tolerance, technical requirements, inspection rules, packaging, Marks and quality certificates, etc., describe the corresponding test methods.

This document is applicable to hot-rolled asymmetric bulb flat steel for applications such as shipbuilding, marine engineering, bridge engineering and steel structures.

2 Normative references

GB/T 222

GB/T 223.5

GB/T 223.9

GB/T 223.12

GB/T 223.14

GB/T 223.16

GB/T 223.19

GB/T 223.26

GB/T 223.40

GB/T 223.54

GB/T 223.62

GB/T 223.63

GB/T 223.69

GB/T 223.72

GB/T 228.1

GB/T 229

GB/T 2101

GB/T 2975

GB/T 4336

GB/T 20066

GB/T 20123

GB/T 20125

3 Terms and Definitions

The following terms and definitions apply to this document.