GB/T 4423-2020Copper and copper alloy cold-drawn rod and bar (English PDF)

3.1 Product classification

Designations, codes, states and specifications of rod and bar shall comply with Table 1. The aspect ratio of the rectangular rod and bar shall meet the requirements of Table 2.

3.2 Product marking

Product marking is indicated in the order of product name, standard number, designation (or code), state, accuracy level and specification.

4.1 Chemical composition

The chemical composition of H96 rod and bar shall meet the requirements of Table 3. The chemical composition of other designations shall meet the requirements of GB/T 5231.

4.2 Dimensions and allowable deviation

4.2.1 Diameter (or opposite margin) and allowable deviation

The diameters (or opposition margins) of copper and brass rod and bar as well as allowable deviation shall meet the requirements of Table 4.

4.2.2 Roundness

The roundness of round rod and bar shall not exceed half of the allowable deviation of the diameter.

4.2.4 Twist

The twist of square, rectangular and regular hexagonal rod and bars shall not Diameter (oropposite margin)

4.2.5 Fillet radius

Filets are allowed at the edges and corners of the cross section of polygonal rod and bar. The fillet radius shall meet the requirements of Table 6.

4.3 Mechanical properties

The mechanical properties of rod and bar at room temperature shall meet the requirements of Table 8 and Table 9.

4.4 Internal quality

Except TU1, TU2, T2, T3, TP2, TCr0.5, H96, H95, other alloy rods and bars shall be inspected for fracture or ultrasonic flaw detection.

4.5 Residual stress

Brass (except H96, H95), tin bronze, silicon bronze and zinc-nickel alloy rods and bars in H01, H02, H04, H06 states can be subjected to residual stress inspection. There shall be no visible cracks in the inspection results.

4.6 Surface quality

The surface of rod and bar shall be bright and clean. There shall be no defects that affect use.

5.1 Chemical composition

The analysis method for chemical composition of rod and bar shall be carried out according to the regulations of GB/T 5121, YS/T 482 or YS/T 483.

5.2 Dimensions and allowable deviation

The measurement method for dimensions of rod and bar shall be carried out according to the regulations of GB/T 26303.2.

5.3 Mechanical properties

5.3.1 The tensile test at room temperature of rod and bar as well as sample preparation method are carried out according to the regulations of GB/T34505-2017.Sample selection shall meet the requirements of Table 10.

5.4 Internal quality

5.4.1 The fracture inspection of rod and bar shall be carried out in accordance with the provisions of YS/T 336.

5.4.2 The ultrasonic flaw detection of rod and bar shall be carried out according to GB/T 3310.

5.5 Residual stress

The residual stress inspection of rod and bar shall be carried out according to the provisions of GB/T 10567.1 and GB/T 10567.2.

5.6 Surface quality

Visually inspect the surface quality of rod and bar.

6.1 Inspection and acceptance

6.1.1 Rod and bar shall be inspected by the supplier's technical supervision department to ensure that the product quality meets the requirements of this Standard. Fill in the quality certificate.

6.1.2 The purchaser shall inspect the received products in accordance with the provisions of this Standard. If the inspection result does not conform to the provisions of this Standard (or order contract), it shall be submitted to the supplier within 1 month from the date of receipt of the product. It shall be solved by negotiation between the supplier and the purchaser. If arbitration is required, arbitration sampling shall be conducted jointly by both parties.

6.2 Batching

Rod and bar shall be submitted for acceptance in batches. Each batch shall be composed of rods and bars of the same designation, specification and state. The weight of each batch does not exceed 5000kg.

6.3 Inspection items

6.3.1 Each batch of rods and bars shall be inspected for chemical composition, dimensions and allowable deviation, internal quality and surface quality.

6.3.2 Each batch of rods and bars shall be inspected for mechanical properties (tensile test or hardness test). Choose either tensile test or hardness test. When not specified in the contract, perform tensile test. When the tensile test is selected, if the purchaser also requires hardness test and it is specified in the contract, hardness test shall also be carried out. The hardness test results are for reference only. When choosing hardness test, when the purchaser also requires tensile test and it is specified in the contract, tensile test shall also be carried out. The tensile test results are for reference only.

6.3.3 When requested by the purchaser, residual stress inspection shall also be carried out.

6.4 Sampling

Product sampling shall meet the requirements of Table 11. Sampling method is carried out in accordance with YS/T 668.

6.5 Determination of inspection result

6.5.1 The value of inspection result shall be rounded according to the provisions of GB/T 8170. Use rounding value comparison method to determine.

6.5.2 When the chemical composition fails, the batch of rods and bars is rejected.

6.5.3 When the dimensions of rod and bar, its allowable deviation and surface quality fail, it is rejected by piece. When the number of rejected pieces in each batch exceeds the acceptable quality limit, the entire batch is rejected or inspected by supplier piece by piece. Only accepted products are delivered.

6.5.4 When there are rejected samples in the test results of mechanical properties, fracture and residual stress, double the number of samples shall be taken from the batch of products (including the one that failed the original inspection) for the reinspection of rejected items. If all retest results are conforming, the batch of products shall be accepted.

6.5.5 When the ultrasonic flaw detection is nonconforming, it shall be rejected by piece.

6.5.6 When there are other defects, it shall be negotiated and determined by both parties.