GB/T 706-2016 in English

《GB/T 706-2016热轧型钢》由TC183（全国钢标准化技术委员会）归口，TC183SC8（全国钢标准化技术委员会型钢分会）执行，主管部门为中国钢铁工业协会。

ChinaStandards.net is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.

This standard is developed in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB/T 706-2008 Hot Rolled Section Steel. The following main technical changes have been made with respect to GB/T 706-2008:

——the contents relevant to hot rolled L-shaped steel are deleted (see Tables 3, 5 and A.5 of 2008 edition);

——the order contents are added (see Chapter 3);

——some permissible dimension and shape deviations are adjusted (see Tables 1 and 2; Tables 1 and 2 of 2008 edition);

——the requirements for permissible weight deviation are adjusted (see 4.4; 3.4 of 2008 edition);

——the representation methods for specification are added (see 4.5)

——the values of sectional area, theoretical weight and sectional characteristic parameters, etc. are adjusted (see Tables A.1, A.2, A.3 and A.4);

This standard was proposed by China Iron and Steel Association.

This standard is under the jurisdiction of National Technical Committee on Iron and Steel of Standardization Administration of China (SCA/TC 183).

The previous editions of this standard are as follows:

——GB/T 706-1965, GB/T 706-1988, GB/T 706-2008;

——GB/T 707-1965, GB/T 707-1988;

——GB/T 9787-1988;

——GB/T 9788-1988;

——GB/T 9946-1988.


Hot Rolled Section Steel

1 Scope

This standard specifies the order contents, the dimension, shape, weight as well as their permissible deviations, the technical requirements, test methods, inspection rules, and the packaging, marking and certification of hot rolled I-steel, hot rolled U-steel, hot rolled equal angle steel and hot rolled unequal angle steel.

This standard is applicable to hot rolled equal angle steel and hot rolled unequal angle steel as well as hot rolled I-steel and hot rolled U-steel with inclination on inner side at the leg part (hereinafter referred to as "section steel").

2 Normative References

The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature

GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method

GB/T 232 Metallic Materials - Bend Test

GB/T 700 Carbon Structural Steels

GB/T 1591 High Strength Low Alloy Structural Steels

GB/T 2101 General Requirement of Acceptance Packaging, Marking and Certification for Section Steel

GB/T 2975 Steel and Steel Products - Location and Preparation of Test Pieces for Mechanical Testing

YB/T 4427 General Requirements for Surface Condition of Hot-rolled Sections

3 Order Contents

The order contracts concluded in accordance with this standard shall include the following technical contents:

a) Product name;

b) Serial number of standard;

c) Designation;

d) Model and specification;

e) Delivery length;

f) Weight and quantity;

g) Other special requirements proposed by the purchaser.

4 Dimension, Shape, Weight and Their Permissible Deviations

4.1 Dimension and representation method

4.1.1 The sectional view and symbols marked of section steels are shown in Figures 1~4.

4.1.2 The sectional dimension, sectional area, theoretical weight and sectional characteristic parameters of section steels shall be in accordance with those specified in Tables A.1~A.4 respectively.

4.2 Dimension, shape and their permissible deviations

4.2.1 The dimension, shape and their permissible deviations of section steels shall be in accordance with those specified in Tables 1~2. As required by the purchaser, the dimension, shape and their permissible deviations of section steels may also comply with requirements stipulated by the agreement between the supplier and the purchaser.



Keys:

h——height;

b——leg width;

d——waist thickness;

t——leg center thickness;

r——inner arc radius;

r1——arc radius at end of leg. Keys

h——height;

b——leg width;

d——waist thickness;

t——leg center thickness;

r——inner arc radius;

r1——arc radius at end of leg;

Z0——distance of gravity center.

Figure 1 Sectional View of I-steel
Figure 2 Sectional View of U-steel

 


Keys:

b——side width;

d——side thickness;

r——inner arc radius;

r1——arc radius at end;

Z0——distance of gravity center. Keys:

B——long side width;

b——short side width;

d——side thickness;

r——inner arc radius;

r1——arc radius at end;

X0——distance of gravity center;

Y0——distance of gravity center.

Figure 3 Sectional View of Equal Angle Steel Figure 4 Sectional View of Unequal Angle Steel

4.2.2 As for the passivation of outer leg edge of I-steel and of outer leg edge and shoulder of U-steel, the round bar in diameter of 0.18t shall not be capable of passing through; as for the passivation of outer end corners and vertex angle of angle steel, the round bar in diameter of 0.18d shall not capable of passing through.

4.2.3 The outer edge inclination and bend deflection of I-steel and U-steel and the top right angle of angle steel shall be inspected at the position no less than 750mm to the end.

4.2.4 The permissible deviation for leg center thickness (t) of I-steel and U-steel is ±0.06t.

4.2.5 Section steels shall be free from obvious torsion.

 
Table 1 Dimension, Shape and Their Permissible Deviations of I-steel and U-steel In: mm
Item Permissible deviation Figure
Height
(h) h<100 ±1.5
100≤h<200 ±2.0
200≤h<400 ±3.0
h≥400 ±4.0
Leg width
(b) h<100 ±1.5
100≤h<150 ±2.0
150≤h<200 ±2.5
200≤h<300 ±3.0
300≤h<400 ±3.5
h≥400 ±4.0
Waist thickness
(d) h<100 ±0.4
100≤h<200 ±0.5
200≤h<300 ±0.7
300≤h<400 ±0.8
h≥400 ±0.9
Outer edge inclination
(T1, T2) T1, T2≤1.5%b
T1+T2≤2.5%b
Bend deflection
(W) W≤0.15d
Curvature I-steel Curvature per meter: ≤2mm
Total curvature: ≤0.20% of total length Applicable to large curvature top-bottom and left-right
U-steel Curvature per meter: ≤3mm
Total curvature: ≤0.30% of total length
Center deviation
(S) I-steel h<100 ±1.5
100≤h<150 ±2.0
150≤h<200 ±2.5
200≤h<300 ±3.0
300≤h<400 ±3.5
h≥400 ±4.0
Note: measuring positions for dimension and shape are shown in corresponding figures.

Table 2 Dimension, Shape and Their Permissible Deviations of Angle Steel In: mm
Item Permissible deviation Figure
Equal angle steel Unequal angle steel
Side width
(B, b) ba≤56 ±0.8 ±0.8
56 90 140 ba>200 ±3.5 ±3.5
Side thickness
(d) ba≤56 ±0.4
56 90 140 ba>200 ±1.4
Top right angle α≤50′
Curvature Curvature per meter: ≤3mm
Total curvature: ≤0.30% of total length Applicable to large curvature top-bottom and left-right
Note: measuring positions for dimension and shape are shown in corresponding figures.
a For unequal angle steel, the long side width B prevail.

4.3 Length and permissible deviation

The delivery length of section steels shall be noted in the contract, and the permissible length deviation shall be in accordance with those specified in Table 3.

Table 3 Permissible Length Deviation of Section Steels In: mm
Length Permissible deviation
≤8 000 +50
0
>8 000 +80
0

4.4 Weight and permissible deviation

4.4.1 Section steels shall be delivered according to theoretical weight, and the theoretical weight shall be calculated according to the density of 7.85g/cm3. Section steels may also be delivered according to actual weight as agreed by the supplier and the purchaser and being noted in the contract.

4.4.2 The permissible weight deviation of section steels shall not exceed ±5%. The weight deviation (%) shall be calculated according to Formula (1). The permissible weight deviation is applicable to a batch of section steels of the same dimension and with mass greater than 1t, and is also applicable to a batch of section steels of the same dimension but with mass not greater than 1t and number greater than 10 sticks.

1 Scope
2 Normative References
3 Order Contents
4 Dimension, Shape, Weight and Their Permissible Deviations
5 Technical Requirements
6 Test Methods
7 Inspection Rules
8 Packaging, Marking and Certification
Annex A (Normative) Sectional Dimension, Sectional Area, Theoretical Weight and Sectional Characteristics of Section Steels