The service life of spiral welded steel pipes is related to the surface decarburization of spiral welded steel pipes. If the surface is decarburized, the strength and wear resistance of the spiral welded steel pipe will be reduced, which will directly affect the service life of the spiral welded steel pipe. If the decarburized layer on the spiral welded steel pipe is not cleaned, the surface hardness and wear resistance of the spiral welded steel pipe will be reduced accordingly, and during the quenching process, the volume change of the inner and outer layers will cause cracks to form on the surface of the workpiece.

How to prevent the decarburization of spiral welded steel pipes, the following the answer:
To solve the problem of surface decarburization, it is mainly necessary to deal with the heat treatment process because decarburization and oxidation of spiral welded steel pipes are carried out at the same time, so during the heat treatment process, the spiral welded steel pipe should be kept away from air as much as possible, which can improve the decarburization phenomenon.

The media that cause decarburization on the surface of spiral welded steel pipes are mainly oxidizing gases such as oxygen, water vapor, and carbon dioxide. When these gases come into contact with the heated spiral welded steel pipes, they will cause oxidation and decarburization of the spiral welded steel pipes. Therefore, it is also very important to control the ratio of carbon dioxide and carbon monoxide in the furnace.

Adding protective gas nitrogen to the spiral welded steel pipe forging furnace is also very effective. Nitrogen can disperse certain oxidizing gases and reduce the decarburization of spiral welded steel pipes.