The Quality Classification of Large-diameter Straight Seam Welded Steel Pipes

The application of large-diameter straight seam welded steel pipes is very common in people’s lives. Do you know what grades the quality of large-diameter straight seam welded steel pipes can be divided into? The following is an introduction to the specific content.

The surface of the general hot-rolled large-diameter straight seam welded steel pipe products is FA, and the large-diameter straight seam welded steel pipe products after pickling are FB. Cold-rolled large-diameter straight seam welded steel pipe products are FB/FC/FD.

Ordinary large-diameter straight seam welded steel pipe products have low surface requirements, such as automobile inner panels, using FB surface. For some general requirements, the outer panels of automobiles are not particularly high, so FC is used. For high-end cars, FD surface is used.

Usually, the pickled large-diameter straight seam welded steel pipe products have FB surface, so they can replace cold-rolled products to make some structural parts.

There are fewer processes at the end, which can save costs for enterprises. Moreover, the surface oxide scale is removed, which makes welding easier.

Relatively speaking, pickled products are easier to weld than hot-rolled products. If they are subsequently oiled or painted, it will be easier and the quality will be better.

In addition, the dimensional accuracy is much better than that of hot-rolled products, and the dimensional accuracy is relatively high compared to hot-rolled large-diameter straight seam welded steel pipe products. In addition, pickled products are flat, the plate shape is also better, and the unevenness is better. The surface finish is also much better than that of hot-rolled products, and the appearance is higher.