GB 912-2008[GB/T 912-2008] Hot-rolled sheets and strips of carbon structural steels and high strength low alloy structural steels (English PDF)

4995.2001 (E)) and "Hot-rolled Steel Sheet of High Yield Stress Structural Quality"

(ISO 4996.1999 (E)).

This standard replaces "Hot-rolled Sheets and Strips of Carbon Structural Steels and

High Strength Low Alloy Structural Steels" (GB/T 912-1989). Compared with GB/T

912-1989, the main changes of this standard are as follows.

— Change from voluntary standard to standard with compulsory-provisions;

— Delete the content related to ply-rolling steel plate in the former standard;

— Adjust the thickness range of products;

— Add the "ordering information";

— Change the delivery state;

— Modify the requirements of surface quality.

This standard was proposed by China Iron and Steel Association.

This standard shall be under the jurisdiction of the National Technical Committee on

Iron and Steel of Standardization Administration of China.

Chief drafting organizations of this standard. Guangdong Entry-Exit Inspection and

Quarantine Bureau, Metallurgical Information and Standardization Institute and Benxi

Iron & Steel (group) Co. Ltd.

Chief drafting staffs of this standard. Li Chengming, Peng Xiaogang, Wang Xaiohu,

Zhang Zhenkun, Zhou Qi, Zhang Xianfeng, Liu Jianbin, Cao Biao and Pei Yu.

The previous edition replaced by this standard is as follows.

— GB/T 912-1989.

Hot-rolled Plates and Strips of Carbon Structural

Steels and High Strength Low Alloy Structural Steels

3.1 The order contract or order according to this standard shall include the following

contents.

5.1 Designation and chemical composition

5.1.1 The designation and chemical composition of steel shall meet the

requirements specified in GB/T 700 and GB/T 1591.

5.2 Smelting process

By converter or electro-smelting.

5.3 Delivery condition

The steel plate and strip shall be delivered with hot rolling or annealed condition.

5.4 Mechanical property and processing property

5.4.1 Tensile strength and elongation percentage of steel sheet and strip shall meet

the requirements of GB/T 700 and GB/T 1591, but the elongation percentage is

permitted to be 5 % less (absolute value) than that specified in GB/T 700 or GB/T

1591.

5.5 Surface quality

5.5.1 Harmful defects, such as the scar, crack, fold, inclusion, bubble and embed

iron-oxide-scale, shall be free from the surface of the steel sheet and strip. Steel sheet

and strip shall be free from any delaminate.

5.5.2 Local defects, such as iron oxide scale in thin layer, corrosion and slight

pockmark, which do not affect using, are allowed to exist on the surface of the steel

sheet and strip. The convex-concave shall not exceed half of the thickness deviation

of the steel sheet and strip, and the permitted minimum thickness of steel sheet and

strip shall be ensured.

6.1 The inspection items, sampling quantity, sampling method and test method of

each batch of steel sheet and strip shall meet the requirements specified in Table 1.

7.1 The inspection and acceptance of steel sheet and strip are in charge of the

supplier's technology and quality supervision department. The purchaser is entitled to

perform inspection and acceptance according to any inspection item specified in this

standard or contract.

7.4 The re-inspection and judgment of steel sheet and strip shall be carried out in

accordance with the requirements of GB/T 17505.

8.1 Packing, marking and quality certificate of steel sheet and strip shall meet the

requirements of GB/T 247.The type of the quality certificate may be according to the

requirements of GB/T 18253.