Inspection steps for LSAW steel pipes

Inspection steps for LSAW steel pipes

1. LSAW steel pipes should be submitted for acceptance in batches, and the batching rules should meet the requirements of the corresponding product standards.

2. The inspection items, sampling quantity, sampling location, and test method of LSAW steel pipes shall be following the provisions of the corresponding product standards. Subject to the consent of the purchaser, hot-rolled seamless LSAW steel pipes can be sampled in batches according to the rolling root group.

3. According to the test results of LSAW steel pipes, if a certain item does not meet the requirements of the product standard, the unqualified ones shall be picked out, and a double number of samples shall be taken from the same batch of straight seamed steel pipes to carry out unqualified items. recheck. If the re-inspection result (including any index required by the project test) is unqualified, the batch of LSAW steel pipes shall not be delivered. The following inspection items are not allowed to be re-inspected when the initial inspection is unqualified:

1) There are white spots in the low-power tissue;

2) Microstructure.

4. If the re-inspection result is unqualified (including the unqualified microstructure of the initial inspection result and items that are not allowed to be re-inspected), the supplier can submit for acceptance one by one; or re-heat treatment (the number of re-heat treatments shall not exceed two ), submit a new batch for acceptance.

5. If there are no special regulations in the product standard, the chemical composition of the LSAW steel pipe shall be checked and accepted according to the melting composition.

LSAW steel pipe is not only used to transport fluids and powdered solids, exchange heat, and manufacture mechanical parts and containers, it is also an economical steel. The use of LSAW steel pipes to manufacture building structure grids, pillars, and mechanical supports can reduce weight, save metal by 20-40%, and can realize factory mechanized construction. The use of straight-seam steel pipes to manufacture highway bridges can not only save steel, simplify construction, but also greatly reduce the area of the protective layer, saving investment and maintenance costs. Therefore, any other type of steel can not replace the LSAW steel pipe, but the LSAW steel pipe can replace some profiles and bars. From people's daily appliances, furniture, water supply, and drainage, gas supply, ventilation, and heating facilities to the manufacturing of various agricultural machinery, the development of underground resources, and the guns, bullets, missiles, and rockets used, LSAW steel pipes are inseparable.