Low carbon steel pipe, also known as mild steel pipes and carbon content from 0.10% to 0.30% in low-carbon steel is easy to accept all kinds of processing such as forging, welding and cutting, commonly used in the manufacturing chain, rivets, bolts, axis. The carbon content of less than 0.25% carbon steel, because of its low intensity, low hardness and soft, it is also known as mild steel pipes. It includes the majority of ordinary carbon steel pipe and part of high-quality carbon structural steel, mostly used in engineering structures without heat treatment, and some by carburizing and other heat treatment is used for wear-resistant mechanical parts.
Low carbon steel pipe annealed structure of ferrite and pearlite, the lower its strength and hardness, good ductility and toughness. Therefore, the cold good formability and can use methods such as crimping, bending, stamping, cold forming. This steel has good weldability. Low carbon content of low carbon steel hardness is low, the poor machinability of normalizing treatment can improve machinability. Low-carbon steel pipes have a greater tendency of aging, both quench aging and the tendency to deformation aging tendencies. When the steel from high temperature and rapid cooling, the ferrite scratch carbon, nitrogen supersaturation at room temperature can slow the formation of iron carbonitride material, and thus improve the strength and hardness of the steel pipe, reduce the ductility and toughness of this phenomenon known as the quench aging. Low carbon steel quenching and air cooling will produce aging. Low-carbon steel large number of dislocations generated by deformation, the elastic interaction from the carbon and nitrogen atoms with dislocations in the ferrite, carbon, nitrogen atoms gather around the dislocations Line. This carbon, nitrogen atom and the dislocation line combination that old Coriolis air mass (Ke lop air mass). It will make the strength and hardness of the steel to improve the ductility and toughness decreased, a phenomenon known as the deformation aging. Deformation than the quench aging on the ductility and toughness of low carbon steel pipe greater harm evident in the tensile curve of the low-carbon steel and lower yield point. Since the yield point until the end of the yield extension, the inhomogeneous deformation and the formation of surface folds with the sample surface, known as the Luders band. A lot of stamping parts tend to be scrapped. There are two prevention methods. A high pre-deformation method, the pre-deformation of the steel also have in place for some time after stamping Luders band, and therefore pre-deformation of steel placed in the stamping before the time not too long. Another steel by adding aluminum or titanium, the formation of stable compounds with nitrogen to prevent the formation of the Coriolis air mass caused by deformation aging.
Originally due to the inherent characteristics of low carbon steel pipe, its scope of use greatly restricted, with some new technology in the steel industry, many of the emerging use of low carbon steel has been a very good development and utilization of domestic large steel mills or steel trading company active in a large sling and domestic enterprises in close cooperation to jointly develop a series of high-tech high-precision high-quality rigging products in the domestic and the global cable industry, has played a very good technology to promote role.