Seamless steel pipe material has different models, of course, different models, the role will follow different, which is different from welded steel pipe, the following Xiaobian will lead you to understand.
Seamless steel pipe material
GB/T8162-1999 (seamless steel pipe for construction). Mainly used for general structure and mechanical structure. Its representative material (brand) : carbon steel 20, 45 steel; Alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.
GB/T8163-1999 (Seamless steel pipe for fluid transport). It is mainly used for conveying fluid pipe on engineering and large equipment. Represents the material (brand) for 20, Q345, etc.
GB3087-1999 (Seamless steel pipe for low and medium pressure boiler). It is mainly used for conveying low and medium pressure fluid pipe of industrial boiler and domestic boiler. It means the material is No. 10 and No. 20 steel.
GB5310-1995 (Seamless steel pipe for high pressure boiler). It is mainly used for high temperature and high pressure conveying fluid collection box and pipeline on boiler of power station and nuclear power station. The material is 20G, 12Cr1MoVG, 15CrMoG, etc.
GB5312-1999 (carbon steel and carbon manganese steel seamless steel tubes for Marine use). Mainly used for Marine boiler and superheater I, II pressure tubes. On behalf of the material 360, 410, 460 steel grade.
The difference with welded steel pipe
Mainly the molding process is different. Ordinary steel pipes, such as tap water pipes, are generally welded by bending flat plates, and you can find a weld on them; The larger diameter is generally spiral weld. And seamless steel pipe is generally molten steel through the annular slit backlog after stretching and other processing process forming, so that there is no weld. In the performance, especially the bearing capacity of ordinary steel pipe has been greatly improved, so it is often used in high pressure equipment.
Such as hydraulic equipment pipeline connection. The weld position of common steel pipe is its weak link, and the quality of weld is also the main factor affecting its overall performance. People who have lived in the north generally have the experience of water pipes or heating pipes being frozen to burst in winter, usually at the weld. Welded pipe is not seamless steel pipe.
Comprehensive material selection and use of domestic and foreign manufacturers, the author thinks: the punch-machine roll selection of cast 50Mn, 60CrMnMo and other medium carbon alloy steel material is more suitable, one is has good strength and wear resistance, the other is suitable for rolling various materials of steel pipe. Hardness control at HB200-240 is more reasonable.
