GB/T 714-2000 Structural Steel for Bridges

GB/T 714-2000 Structural Steel for Bridges

This standard specifies the classification and grades, technical requirements, test methods, test rules, packaging, marking, transportation and storage of Structural Steel for Bridges.

Structural steel for bridges includes bridge structural steel and bridge special steel. Bridge structural steel includes the following types of steel: Carbon structural steel, Low alloy high strength structural steel, High strength structural steel and Steel for welding. Bridge special steel includes steel for reinforcing bars, steel for prestressed concrete and steel for special welding purpose.

This standard applies to steel products in the form of hot-rolled plate, cold-rolled plate (strip) and wire rod.

The technical requirements of this standard include basic requirements, chemical composition requirements, mechanical properties requirements, test requirements, inspection regulations and so on.

The strength grade and corresponding delivery state of structural steel for bridges are shown in Tables 1 - 3.

The chemical composition of steel products shall meet the requirements specified in Table 4.

The mechanical properties of steel products shall meet the requirements specified in Table 5. The mechanical properties of steel products shall be tested in accordance with the test method and way specified in Table 6.

The standard test pieces and test method for sampling inspection of steel products shall be specified in Table 7.

The analytical method for chemical composition of steel products shall be specified in Table 8.

The requirements for packaging, marking, transportation and storage of steel products shall be specified in Table 9.

Table 1 Strength grade and delivery state of carbon structural steel

Table 2 Strength grade and delivery state of low alloy high strength structural steel

Table 3 Strength grade and delivery state of high strength structural steel

Table 4 Chemical composition of steel products

Table 5 Mechanical properties of steel products

Table 6 Test method and test way for steel products

Table 7 Standard test pieces and test method for sampling inspection

Table 8 Analytical method for chemical composition

Table 9 Requirements for packaging, marking, transportation and storage

GB/T 714-2000 bridge structural steel

GB/T 714-2000 bridge structural steel is made of high-quality carbon structural steel and low-alloy structural steel. It has the characteristics of higher tensile strength, good surface quality, excellent plasticity and weldability, and higher strength. It is suitable for standardization and production of steel bridges.

1 Scope

This standard specifies the ordering, classification and delivery status of bridge structural steel for general use.

2 Normative references

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

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

GB/T 223.3 Methods for chemical analysis of iron, steel and alloy - The cupferron photometric method

GB/T 223.5 Methods for chemical analysis of iron, steel and alloy - The nital-potentiometric titration method

GB/T 223.9 Methods for chemical analysis of iron, steel and alloy - Determination of aluminum content - Chrom azurol photographic method

GB/T 223.11 Methods for chemical analysis of iron, steel and alloy - Determination of chromium content - Potentiometric or visual titration method

GB/T 223.12 Methods for chemical analysis of iron, steel and alloy - Determination of copper content - Electrogravimetric method

GB/T 223.14 Methods for chemical analysis of iron, steel and alloy - Determination of lead content - Flame atomic absorption spectrophotometric method

GB/T 223.16 Methods for chemical analysis of iron, steel and alloy - Determination of silicon content - Molybdosilicate spectrophotometric method

3 Classification and designation

The bridge structural steel of this standard is classified into two types: Q235 and Q345, based on the tensile strength.

4 Ordering

4.1 It is specified that the products concerned comply with the requirements of this standard upon ordering (including the grade and numerical designation of the steel).

4.2 When ordering, it shall also indicate the delivery status, packaging, product specification and inspection documents, as well as special requirements, etc.

5 Technical requirements

5.1 Chemical composition

The chemical composition of bridge structural steel (mass fraction, %) is shown in Table 1.

Table 1 Chemical composition of bridge structural steel

5.2 Mechanical properties

The mechanical properties of bridge structural steel (yield strength, tensile strength, elongation, reduction of area) are shown in Table 2.

Table 2 Mechanical properties of bridge structural steel

6 Delivery status

6.1 Forged or rolled products.

6.2 Steel forgings or rolled products, after normalizing treatment, should meet the requirements of Table 2 for mechanical properties.

7 Inspection and acceptance

7.1 Any inspection and acceptance of bridge structural steel products shall be performed according to the relevant product provisions of this standard.

7.2 The buyer may entrust a third-party organization to inspect and accept the products.

7.3 Any dispute arising from the inspection and acceptance shall be settled through negotiation between the buyer and the seller.