Steel pipes are generally divided into seamless steel pipes and welded steel pipes according to production methods. This time we mainly introduce welded steel pipes, that is, seam steel pipes.

During the production and transportation of seamless steel pipes, oil stains will inevitably adhere to the surface of the seamless pipe, which will affect the quality of the seamless pipe rust removal and phosphating, and reduce the adhesion between the coating and the substrate.

According to different production methods (or processes), seamless steel pipes can use steel ingots, continuous casting billets, rolling billets, forging or centrifugal casting hollows, etc.

Seamless pipes are generally non-magnetic or very weak, but the presence of magnetism will also affect our failure in use, so for many seamless steel pipe factories, it is still necessary to eliminate the magnetic properties of seamless pipes.

When the seamless steel pipe is cold drawn, due to shortcomings such as livelihood cracks in the hot-rolled tube blank, or after the high-precision cold-drawn pipe is made into a cylinder, cracks occur during the operation.

The gas dissolved in the high-temperature liquid metal during the welding of seamless steel pipes will escape in the form of bubbles during the cooling process.