- 1 - ICS 77.140.50  
H 46  
 
 
 
 
National Standard  
of the People's Republic of China  
 
 
GB912 - XXXX  
 GB/T 912 -1989 is annulled  
 
 
Hot-rolled sheets and strips of carbon 
structural steels and high strength low 
alloy structural steels  
 
(ISO4995:2001 (E), ISO4996:199 9 (E), NEQ)  
  
Draft for approval  
 
 
 Issue Date: 200X – XX – XX Implementation Date: 200X – XX – XX 
 
Issued by the General Administration of Quality Supervision, Inspection and 
Quarantine  
of the People's Republic of China  
 
Standardisation Administration  of the People's Republic of China (SAC)  
- 2 - GB 912 -XXXX  
 
Foreword  
 
 
 
This Standard contains mandatory provisions; sections 5.1.2, 5.4.1, 5.4.3, and 8.2 are 
mandatory articles.  
 
The consistency of this Standard with ISO 4995:2000 (E), Hot -rolled steel sheet of  structural 
quality (English version) and ISO 4996:1999 (E), Hot -rolled steel sheet of high yield stress 
structural quality (English version) is non -equivalent.  
 
Standard GB/T 912 -1989, Hot -rolled plain carbon and low alloy structural steel sheets and stri ps is 
annulled from the date of implementation of this Standard.  
 
In comparison with GB/T 912 -1989, the main changes to this Standard are:  
− the Standard has been modified from being a recommendatory standard to a mandatory 
provisions standard;  
− relevant cont ents regarding rolled steel sheet in the original standard have been cancelled;  
− the product thickness range has been revised;  
− the content of the goods order has been added;  
− the goods delivery state has been changed;  
− the requirements for appearance quality have been modified.  
 
This standard is proposed by the China Iron and Steel Association.  
 
This standard is under the jurisdiction of the National Technical Committee for Standardisation of 
Iron and Steel.  
 
The main organisations that participated in the dra fting of this standard are:  
Guangdong Entry -Exit Inspection and Quarantine Bureau;  
China Metallurgical Information & Standardisation Institute;  
Benxi Iron & Steel (Group) Co., Ltd.  
 
Main drafters of this standard:  LiChengMing, PengXiaoGang, WangXiaoHu, Z hangZhenKun, 
ZhouQi, ZhangXianFeng, LiuJianBin, CaoBiao, PeiYu.  
 
This standard was first issued in 1989.  
 
 
 
 
 
 - 3 -           GB 912 - XXXX  
Hot-rolled sheets and strips of carbon structural steels and high 
strength low alloy structural steels  
 
 
1 Scope  
This sta ndard sets the requirements for the testing methods, inspection rules, packaging, marking, 
dimensions, appearance, weight, technical requirements, permissible tolerance, content of orders 
and quality certificates of hot -rolled sheets and strips of carbon s tructural steels and high strength 
low alloy structural steels.  
 
This standard applies to hot -rolled sheets and strips of carbon structural steels and high strength low 
alloy structural steels with a thickness of less than 3mm.  
2 Normative References  
The p rovisions of the following documents become provisions of this Standard after being 
referenced. For dated reference documents, all later amendments (excluding corrigendum) and 
versions do not apply to this Standard; however, the parties to the agreement ar e encouraged to 
study whether the latest versions of these documents are applicable. For undated reference 
documents, the latest versions apply.  
 
GB/T 222 Permissible tolerances for the chemical composition of steel products;  
 
GB/T 223.3 Methods for chemic al analysis of iron, steel and alloy - The diantipyrylmethane 
phosphomolybdate gravimetric method for the determination of phosphorus content;  
 
GB/T 223.5 Methods for chemical analysis of iron, steel and alloy - The reduced molybdosilicate 
spectrophotometr ic method for the determination of acid -soluble silicon content;  
 
GB/T 223.10 Methods for chemical analysis of iron, steel and alloy The cupferron separation -
chrome azurol S photometric method for the determination of aluminium content;  
 
GB/T 223.11 Method s for chemical analysis of iron, steel and alloy - The ammonium persulphate 
oxidation volumetric method for the determination of chromium content;  
 
GB/T 223.14 Methods for chemical analysis of iron, steel and alloy The N -benzoy -N-
phenylhydroxylamine extrac tion photometric method for the determination of vanadium content;  
 
GB/T 223.17 Methods for chemical analysis of iron steel and alloy - The diantipyrylmethane 
photometric method for the determination of titanium content;  
 
GB/T 223.18 Methods for chemical a nalysis of iron, steel and alloy - The sodium thiosulphate 
separation iodimetric method for the determination of copper content;  
 
GB/T 223.19 Methods for chemical analysis of iron steel and alloy - The neocuproine -chloroform 
extraction photometric method f or the determination of copper content;  
 - 4 - GB/T 223.23 Methods for chemical analysis of iron, steel and alloy - The dimethylglyoxime 
spectrophotometric method for the determination of nickel content;  
 
GB/T 223.24 Methods for chemical analysis of iron, steel and alloy - The extraction separation - 
The dimethylglyoxime spectrophotometric method for the determination of nickel content;  
 
GB/T 223.32 Methods for chemical analysis of iron, steel and alloy - The hypophosphite reduction -
iodimetric method for the dete rmination of arsenic content;  
 
GB/T 223.37 Methods for chemical analysis of iron steel and alloy - The indophenal blue 
photometric method for the determination of nitrogen content after distillation separation;  
 
GB/T 223.40 Iron steel and alloy —Determinati on of niobium content by the sulphochlorophenol -S 
spectrophotometric method;  
 
GB/T 223.58 Methods for chemical analysis of iron, steel and alloy - The sodium arsenite -sodium 
nitrite titrimetric method for the determination of manganese content;  
 
GB/T 223.5 9 Methods for chemical analysis of iron, steel and alloy - The reduced 
molybdoantimonyl phosphoric acid photometric method for the determination of phosphorus 
content;  
 
GB/T 223.60 Methods for chemical analysis of iron, steel and alloy - The perchloric aci d 
dehydration gravimetric method for the determination of silicon content;  
 
GB/T 223.63 Methods for chemical analysis of iron, steel and alloy - The sodium (potassium) 
periodate photometric method for the determination of manganese content;  
 
GB/T 223.64 Me thods for chemical analysis of iron, steel and alloy - The flame atomic absorption 
spectrometric method for the determination of manganese content;  
 
GB/T 223.68 Methods for chemical analysis of iron, steel and alloy - The potassium iodate titration 
method after combustion in the pipe furnace for the determination of sulphur content;  
 
GB/T 223.71 Methods for chemical analysis of iron, steel and alloy - The gravimetric method after 
combustion in the pipe furnace for the determination of carbon content;  
 
GB/T 223.72 Methods for chemical analysis of iron, steel and alloy - The alumina chromatographic 
separation -barium sulphate gravimetric method for the determination of sulphur content;  
 
GB/T 228 Metallic materials --Tensile testing at ambient temperature;  
 
GB/T 232 Metallic materials --Bend test;  
 
GB/T 247 General rules of acceptance, packaging, marking and certification for steel plates (sheets) 
and strips;  
 
GB/T 700 Carbon structural steels;  
 
GB/T 709 Dimension, shape, weight and tolerances for hot -rolled steel plates and sheets;  - 5 -  
GB/T 1591 High strength low alloy structural steels;  
 
GB/T 2975 Steel and steel products - Location and preparation of test pieces for mechanical testing 
(GB/T 2975 -1998, eqv ISO 377:1997);  
 
GB/T 4336 Standard test method for spark disc harge atomic emission spectrometric analysis of 
carbon and low -Alloy steel (routine method);  
 
GB/T 17505 Steel and steel products - General technical delivery requirements (GB/T 17505 -
1998,eqv ISO 404:1992);  
 
GB/T 18253 Steel and steel products - Types of inspection documents (GB/T 18253 -2000, eqv ISO 
10474: 1991)  
 
GB/T 20066, Steel and iron - Sampling and preparation of samples for the determination of 
chemical composition (GB/T 20066 -2006, ISO14284: 1996 IDT);  
 
YB/T 081 Rule for rounding off numerical val ues and judgement of testing values for technical 
standards of metallurgy.  
 
 
3 Order contents  
3.1 According to this Standard, the contract or order form for goods orders should include the 
following contents:  
a) Standard serial number;  
b) Product name (she ets, strips);  
c) Trademark;  
d) Dimension:  
e) Edge state (edge trimmed EC, edge non -trimmed EM);  
f) Thickness precision (PT.A, PT.B);  
g) Weight;  
h) Delivery state;  
i) Applications;  
j) Special requirements.  
 
3.2 If contents e), f) are not clarified in the pu rchase contract, the following rules apply:  
a) Strips usually delivered as edge non -trimmed, but delivered sheets cut from strips usually as 
edge trimmed;  
b) Thickness precision should conform to general precision (PT.A category).  
 
4 Dimension, appearance,  weight and permissible tolerance  
The dimensions, appearance, weight and permissible tolerances of the strips and sheets - 6 - should conform to the requirements set out in GB/T709.  
5. Technical requirements  
5.1 Trademark and chemical composition  
5.1.1 The trademar k and chemical composition of the steel should conform to the 
requirements set out in GB/T 700 and GB/T 1591.  
5.1.2 The content of arsenic in the steel should not exceed 0.080%; the content of arsenic in 
steel smelted using arsenic mine to smelt pig iron s hould be decided by the supplier and 
should be agreed upon by both parties. If there is no arsenic content in the raw materials, it 
is not necessary to carry out arsenic analysis.  
5.1.3 The permissible tolerance of the chemical composition of finished stee l sheets and 
strip products should conform to the requirements set out in GB/T 222.  
5.2 Smelting methods  
The steel should be smelted in a converter or electric furnace.  
5.3 Delivery state  
The delivery state of the steel sheets and strips should be hot roll ing state or annealing state.  
5.4 Mechanical property and technological property  
5.4.1 The tensile strength and elongation of the steel sheets and strips should conform to the 
requirements set out in GB/T700 and GB/T1591; however, elongation is permitted t o be 
lower than 5% of the elongation set out in GB/T700 or GB/T1591 (absolute value).  
5.4.2 According to the request of the buyer, the yield strength of the steel sheets and strips 
may conform to the requirements set out in GB/T700, GB/T1591.  
5.4.3 The ste el sheets and strips should pass the 1800C bend test. The bend diameter of the 
test sample should conform to the requirements set out in GB/T700, GB/T1591.  
5.4.4 According to the requests of the buyer, low alloy structural steels and Q235 carbon 
structural  steels used for cold stamping may undergo the bend test regarding bend diameter 
equals sample thickness.  
5.5 Appearance quality  
5.5.1 There should be no faults on the surface of the steel sheets and strips which may cause 
damage to the use of the steel, s uch as scabs, cracks, folds, inclusions, bubbles and rolled -in 
scales, and the steel sheets and strips may not be stratified.  
5.5.2 Minor faults that do not affect the use of the steel, such as thin layers of scale, iron 
rust, slight spots, or scratch mark s, are permitted on the surface of the steel sheets and strips. 
The degree of unevenness of these flaws may not exceed one half of the tolerance of the 
thickness of the steel sheets and strips, and the permissible minimum thickness of the steel 
sheets and strips should be ensured.  
5.5.3 Treatments for steel sheets surfaces are allowed. The treatment location should be level 
with no edges and corners, and the permissible minimum thickness of the steel sheets and 
strips should be ensured.  
5.5.4 With regard t o strips, there is no chance of cutting off a faulty part, and so delivery 
with faults is permitted; however, faulty part should not exceed 8% of the total length of 
each roll strip.  
6. Test methods  - 7 - 6.1 The test items, sample quantity, sample methods and test  methods of each batch of steel 
sheets and strips should conform to the requirements set out in Table 1.  
Table 1 Test item, sample quantity, sample method and test method  
Serial 
number  Test item  Sample quantity 
(number)  Sample method  Test method  
1 Chemica l 
composition  1 per each furnace  GB/T20066  GB/T223,  
GB/T4336  
2 Tensile test  1 GB/T2975  GB/T228  
3 Bend test  1 GB/T2975  GB/T232  
 
 
6.2 Carry out a visual inspection to check the surface quality of the sheets and strips.  
 
7. Test rules  
7.1 The Quality and Tech nology Supervision Department of the supplier should be 
responsible for the checking and acceptance of the steel sheets and strips. The buyer has 
the right to carry out checking and acceptance according to any one of the test items set 
out in this Standard  or the purchase contract.  
7.2 The acceptance of the steel sheets and strips should be made in the form of batches; 
each batch of steel sheets and strips should comprise the same trademarks, same furnace 
numbers, same quality grades, and same delivery stat es, and the weight of each batch 
should not exceed 60 tonnes.  
7.3 Mixed batches of steel sheets and strips smelted in a steel -smelting furnace with 
lower nominal capacity should conform to the relevant requirements set out in GB/T700 
and GB/T1591.  
7.4 The re-checking and determination of steel sheets and strips should conform to the 
requirements set out in GB/T17505.  
 
8 Packaging, marking and quality certificate  
8.1 The packaging, marking and quality certificate of the steel sheets and strips should 
conform to the requirements set out in GB/T247. The type of quality certificate of the sheets 
and strips may conform to the requirements set out in GB/T18253.  
8.2 The supplier should provide illustration marks and quality certificates in Chinese for the 
sheets and strips.  
9. Rounding off of numerical value  
9.1 The rounding off of numerical values should conform to the requirements set out in 
YB/T081.