Spiral steel pipe is made of strip steel coil as raw material, extruded at room temperature, bent into a spiral shape, and welded with inner and outer seams by automatic double-wire double-sided submerged arc welding process. The raw materials are strip steel coil, welding wire, and flux.
The decarburization treatment of spiral pipe directly affects its service life, that is, its quality. It can be seen that the impact of decarburization on spiral pipe. If the surface is decarburized, the strength and wear resistance of the spiral pipe will decrease, which directly affects the service life of the spiral pipe. If it is a decarburized layer on the spiral pipe, the hardness of the surface layer of the spiral pipe will decrease, and during the quenching process, the volume of the inner and outer layers will cause cracks on the surface of the workpiece.
The medium that causes decarburization on the surface of the spiral pipe is mainly oxidizing gases such as oxygen, water vapor and carbon dioxide. When these gases come into contact with the hot spiral pipe, the spiral pipe will be oxidized and decarburized. Therefore, it is also very important to control the ratio of carbon dioxide and carbon monoxide in the furnace.
To fundamentally deal with decarburization on the surface of the spiral tube, the first step is to use heat treatment. Because decarburization and the spiral tube are carried out at the same time, during the heat treatment process, it is best to prevent the spiral tube from contacting with the air as much as possible, which can improve the appearance of decarburization.
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