Inspection steps for straight seam steel pipe

1. Straight seam steel pipes should be submitted for acceptance in batches, and the batching rules should comply with the provisions of the corresponding product standards.

2. The inspection items, sampling quantities, sampling locations, and test methods of straight seam steel pipes shall be by the provisions of the corresponding product standards. With the purchaser's consent, the hot-rolled seamless straight seam steel pipe can be sampled in batches according to the rolling root group.

3. As for the test results of straight seam steel pipes, when a particular item does not meet the requirements of the product standard, the unqualified ones should be picked out, and from the same batch of straight seam steel pipes, double the number of samples should be taken, and the unqualified items should be checked. recheck. If the re-inspection results (including any index required by the project test) are unqualified, the batch of straight seam steel pipes shall not be delivered. The following inspection items are not allowed to be re-inspected if the initial inspection fails: 1) There are white spots in the low magnification tissue; 2) Microstructure.

4. For straight seam steel pipes with unqualified re-inspection results (including unqualified microstructures in initial inspection results, and re-inspection items are not allowed), the supplier may submit them for acceptance one by one; or re-heat treatment (the number of re-heat treatments shall not exceed two times) ), to submit a new batch for acceptance.

5. If there is no special provision in the product standard, the chemical composition of the straight seam steel pipe shall be checked and accepted according to the smelting composition.