Spiral steel tubes are produced from strip steel coils as raw materials, which are pressed at room temperature and bent into a spiral shape. They are then welded with an automatic double-wire double-sided submerged arc welding process to form the spiral seam both internally and externally. The raw materials used include strip steel coils, welding wires, and fluxes.
The decarburization treatment of spiral tubes directly affects their service life, which is essentially a reflection of their quality. The impact of decarburization treatment on spiral tubes is significant; if the surface is decarburized, the strength and wear resistance of the spiral tube will decrease, thereby directly affecting its service life. Furthermore, if a decarburized layer exists on the spiral tube, the hardness of the surface layer will decrease, and during quenching, cracks may form on the surface of the workpiece due to volume differences between the inner and outer layers.
The primary media contributing to decarburization on the surface of spiral tubes are oxidizing gases such as oxygen, water vapor, and carbon dioxide. When these gases come into contact with hot spiral tubes, oxidation and decarburization of the tubes occur. Therefore, controlling the ratio of carbon dioxide to carbon monoxide inside the furnace is also of great importance.
The fundamental approach to addressing decarburization on the surface of spiral tubes involves carrying out the necessary heat treatment procedures. Since decarburization occurs concurrently with the heat treatment of spiral tubes, it is crucial to minimize the contact between the spiral tubes and air during the heat treatment process. This can help improve the appearance of decarburization and mitigate its effects.
