GB/T 3078-2019Quality structural steel cold drawn bars (English PDF)

Foreword

This Standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This Standard replaces GB/T 3078-2008, Quality structural steel cold drawn bars. Compared with GB/T 3078-2008, the major changes of this Standard are as follows:

-- Add terms and definitions (see Chapter 3);

-- Add delivery state code symbols (see 7.3.1);

-- Modify the macrostructure requirements to comply with the provisions of GB/T

-- Clarify the test method (see Chapter 7, Chapter 7 of version 2008);

-- Standardize the group approval rules (see Chapter 8, Chapter 8 of version 2008);

-- Add provisions for the surface roughness level of cold drawn bars (see 7.9.4).

This Standard was proposed by China Iron and Steel Industry Association.

This Standard shall be under the jurisdiction of National Technical Committee 183 on Iron and Steel of Standardization Administration of China (SAC/TC 183).

The drafting organizations of this Standard: Dongbei Special Steel Group Co., Ltd., Jiangyin Xingcheng Special Steel Works Co., Ltd., Fangda Special Steel Technology Co., Ltd., China Metallurgical Information and Standardization Institute, Liaoning Xindali-type steel Co., Ltd., Xiwang Group Company Limited.

The drafters of this Standard: Jin Weisong, Hao Xixiu, Xu Xiaohong, Zhuang Na, Yan Chengming, Zheng Shuguo, Wen Zhengmao, Zhang Qingsheng, Zhang Kui, Xin Lin, Wang Xinhe.

The previous versions of the standards which are replaced by this Standard are:

1 Scope

This Standard specifies the classification, ordering content, size, shape and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificates of structural steel cold drawing and cold drawing polish steels.

This Standard applies to quality carbon structural steel and alloy structural steel cold drawing bars (round steel, square steel and hexagonal steel) and cold drawing polish round steel (hereinafter collectively referred to as "steel").

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest edition (including all amendments) applies to this document.

3 Terms and definitions

Terms and definitions determined by GB/T 341-2008 and GB/T 3207-2008 are applicable to this document. For ease of use, some of the terms and definitions in GB/T 341-2008 and GB/T 3207-2008 are repeated below.

4 Classification

Steels, according to the use and processing purposes, are divided into:

1) Steel for hot-press processing (UHP);

3) Steel for cold forging (UCF);

3) Steel for hot forging (UHF).

5 Order content

Contracts which are ordered under this Standard shall include the following contents:

c) designation or unified digital code of the steel;

e) size, shape and allowable deviation (see Chapter 6);

f) use and processing purposes (when it is not specified, perform according to steel for cutting);

i) cold or hot forging (see 7.6, if it is required);

j) decarburization layer (see 7.8, if it is required);

k) special requirements (see 7.10, if it is required).

6 Size, shape and allowable deviation

6.1 The size, shape and allowable deviation of cold drawing steel bars shall comply with the provisions of GB/T 905-1994. The specific requirements shall be indicated in the contract. If it is not specified, perform according to provisions of level-h11.

6.2 The size, shape and allowable deviation of cold drawing polish round steel shall comply with the provisions of GB/T 3207-2008. The specific requirements shall be indicated in the contract. If it is not specified, perform according to provisions of levelh11.

7 Technical requirements

8 Test method

The inspection items and test methods of each batch of steels shall comply with the requirements of Table 6.

When the electroslag steel is batched according to the smelting master furnace number, take the sampling quantity the same as that of the electric arc furnace steel; however, for the chemical composition analysis, still take one for each electroslag furnace number.

9 Inspection rules

10 Packaging, marking and quality certificate

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