1. During the forming process, the deformation of the steel plate is uniform, the residual stress is small, and the surface is not scratched. The processed spiral steel pipe has greater flexibility in the size range of diameter and wall thickness, especially in the production of high-grade steel-gra

There are two possibilities for the formation of surface defects of spiral steel pipes: one is that the material itself is not plastic during the deformation process, resulting in the formation of cracks and external folds; the other is that the surface of the material is oxidized to cause surface d

1. Fake and inferior thick-walled steel pipes are prone to folding.2. Fake and inferior thick-walled steel pipes often have pockmarked surfaces.3. Fake and inferior thick-walled steel pipes are prone to scarring on the surface.4. Fake and inferior materials are prone to cracks on the surface.5. Fake

In the process of anti-corrosion construction of oil and gas pipelines, the surface treatment of large-diameter submerged arc steel pipes is a key factor in determining the service life of pipeline anti-corrosion, and it is the premise that the anti-corrosion layer and large-diameter submerged arc s