How to prevent decarburization of thick-walled spiral steel pipe

　　The service life of spiral steel pipe is positively related to the decarbonization of the surface of ApI 5L X42 Large Diameter Spiral Steel Custom Pipeline. If the surface decarbonization, the strength and wear resistance of spiral steel pipe will be reduced, which directly affects the service life of spiral steel pipe. If the decarbonization layer on the spiral steel pipe is not washed clean, the hardness and wear resistance of the surface layer of the spiral steel pipe will be correspondingly reduced, and in the process of quenching, cracks will be formed on the surface of the workpiece due to the volume change of the inner and outer layers.

　　In order to deal with the decarbonization problem on the surface, the heat treatment process is the main one, because decarbonization and oxidation of spiral steel pipe are carried out simultaneously. Therefore, in the heat treatment process, the spiral steel pipe and air should not be allowed to contact, so as to improve the decarbonization phenomenon.

　　Oxygen, water vapor and carbon dioxide are the main medium for decarburization on the surface of helical pipe. When these gases are in contact with the heated helical pipe, they will form oxidation and decarburization of helical pipe. Therefore, the proportion of carbon dioxide and carbon monoxide in the furnace is also very important.

　　It is also very useful to add protective gas nitrogen to the spiral steel pipe forging furnace. Nitrogen may disperse some oxidizing gas to reduce decarbonization of spiral steel pipe.