Straight seam welded steel pipe inspection steps

In the purchase of steel pipes for daily work projects, the purchase of straight seam welded steel pipes is also relatively common, but for the acceptance steps after purchase, I believe you may not understand very comprehensively. Next, we list a relatively complete set of inspection steps to help everyone to accept.

1. Longitudinal welded steel pipes should be submitted for acceptance in batches, and the group batch 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 welded steel pipes shall be by the provisions of the corresponding product standards. With the consent of the purchaser, the hot-rolled seamless straight seam steel pipe can be sampled in batches according to the rolling root group.

3. In the test results of straight seam welded steel pipes, when a certain 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 welded steel pipes, double the number of samples will be taken for unqualified inspection. Recheck of the project. If the re-inspection results (including any index required by the project test) are unqualified, the batch of longitudinally welded 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 welded steel pipes with unqualified re-inspection results (including unqualified microstructures in the 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) times), a new batch is proposed for acceptance.

5. If the product standard does not make special provisions, the chemical composition of the straight seam welded steel pipe shall be checked and accepted according to the smelting composition.

There are often two choices for straight seam steel pipes in industrial production. One option is to use ordinary straight seam welded steel pipes, and the other option is to use straight seam welded steel pipes with good performance. In the process of long-term production practice, enterprises have generally reached a consensus that this kind of longitudinally welded steel pipe with multiple characteristics is superior to ordinary longitudinally welded steel pipes in many aspects. The reason why this kind of straight seam welded steel pipe is slightly better than the ordinary straight seam welded steel pipe is mainly because this kind of straight seam welded steel pipe has several characteristics that the straight seam welded steel pipe does not have.