GB/T 714-2025Structural steel for bridge (English PDF)

1 Scope

This Document specifies the designation method, ordering details, manufacturing process, technical requirements, test methods, inspection rules, packaging, marking, and quality certificate of structural steel for bridge.

This Document applies to single-rolled steel plates for bridge structural steel with a thickness not exceeding 150 mm, and hot-rolled steel strips and sheared steel plates for bridge structural steel with a thickness not exceeding 25.4 mm (hereinafter referred to as steel plates and strips).

2 Normative References

The provisions in following documents become the essential provisions of this Document through reference in this Document. For the dated documents, only the versions with the dates indicated are applicable to this Document; for the undated documents, only the latest version (including all the amendments) is applicable to this Document.

GB/T 222 Permissible tolerances for chemical composition of steel products

GB/T 223 (all parts) Iron, steel and alloy - Methods for chemical analysis

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 testing method

GB/T 247 General rule of package, mark and certification for steel plates (sheets) and strips

GB/T 709 Dimension, shape, weight and tolerance for hot-rolled steel strip plate and sheet

GB/T 2970 Method for ultrasonic testing of thicker steel plates

GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing

GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)

GB/T 5313 Steel plate with through-thickness properties

GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values

GB/T 17505 Steel and steel products - General technical delivery requirements

GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition

GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)

GB/T 20124 Steel and iron - Determination of nitrogen content - Thermal conductimetric method after fusion in a current of inert gas (Routine method)

GB/T 20125 Low-alloy steel - Determination of multi-element contents - Inductively coupled plasma atomic emission spectrometric method

3 Terms and Definitions

For the purposes of this Document, the following terms and definitions apply.

4 Designation Method

The steel designation consists of four parts: the first letter of the pinyin (Qu) for "yield strength", the specified minimum yield strength value, the first letter of the pinyin (qiao) for "bridge", and the quality grade symbol.

NOTE 1: Q + specified minimum yield strength value + q, abbreviated as steel grade. EXAMPLE 1: Q420qD. Where:

Q - the first letter of the pinyin (Qu) for "yield strength";

420 - the specified minimum yield strength value, in MPa;

q - the first letter of the pinyin (qiao) for "bridge";

D - quality grade D.

Bridge steel with weathering resistance properties is designated by adding "weathering" (NH) after the above-mentioned designation.

NOTE 2: Q + specified minimum yield strength value + q + NH, also abbreviated as steel grade. EXAMPLE 2: Q420qDNH.

NH - the first letter of the pinyin (Nai Hou) for "weathering".

When thickness-direction properties are required for steel plates, a symbol representing the thickness-direction (Z-direction) property level (Z15, Z25, Z35) shall be added after the designations specified above, such as Q420qDZ35, Q420qDNHZ35.

5 Ordering Details

Contracts or orders placed according to this Document shall include at least the following:

a) This Document number;

b) Product name;

c) Designation;

d) Specification;

e) Dimensions, shape, and precision requirements;

f) Weight (quantity);

g) Delivery condition;

h) Special requirements.

6 Manufacturing Process

7 Technical Requirements