The application of large-diameter straight seam welded steel pipes has become very common in people’s lives. So, do you know what grades the quality of large-diameter straight seam welded steel pipes can be divided into? Let me introduce you to the specific content below.

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

Ordinary large-diameter straight seam welded steel pipe products do not have high surface requirements. For example, automobile inner panels use FB surfaces. For some exterior panels of cars whose general requirements are not particularly high, use FC. For high-end cars, use FD surface.

Usually, pickled large-diameter straight seam welded steel pipe products have an FB surface, so they can be used to make some structural parts instead of cold-rolled products.

There are a few fewer steps later, which can save costs for the company. Moreover, the iron oxide scale on the surface is removed, making welding easier.

Relatively speaking, compared with hot-rolled products, pickling products are easier to weld. If there is subsequent oiling, painting, etc., 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. Moreover, the pickled products are smooth, have better plate shape, and have better unevenness, etc. The surface finish is much better than that of hot-rolled products, and it is more beautiful.