(1) Plasticity (perforation performance). Bearing cold drawn seamless steel pipe at high temperature has good plasticity and perforation performance, but the heating temperature should not be too high, the general control of 1150 ℃ or so, the temperature is too high prone to grain growth (overheating), reducing metal perforation performance.
(2) Thermal conductivity. Bearing cold drawn seamless steel pipe thermal conductivity lower than the low carbon steel should be appropriate to control the furnace temperature (especially the heating of large cross-section bearing cold drawn seamless steel pipe billet).
(3) Mechanical properties. The tensile strength of the cold drawn seamless steel pipe under normal temperature is much higher than that of C0.3% carbon steel (about doubled), and the hardness is high and the deformation is difficult in cold working. Therefore, spheroidizing annealing is carried out before cold deformation, To improve the plasticity and reduce the hardness, to 1000 ℃ above the difference between the two very little. Bearing cold drawn seamless steel pipe hot rolling is not much difficulty.
(4) Deformation resistance. Bearing cold drawn seamless steel pipe has a high deformation resistance (see metal deformation resistance) and the sensitivity of the temperature is greater, the lower the temperature deformation resistance is higher. Hot rolled bearings cold rolled seamless steel pipe to prevent rolling cold steel. The production of bearing cold drawn seamless steel pipe pipe is sometimes limited by the sizing machine and straightening machine capacity, this is because the bearing cold drawn seamless steel pipe wall thickness, coupled with low deformation resistance at low temperature, making the rolling force and straightening force A significant increase. Cold drawn bearing cold drawn seamless steel pipe pulling force than pulling low-carbon steel pipe about 50% higher. The following are the same as the "
(5) Wide spread. Bearings cold drawn seamless steel pipe width than carbon steel about 10% to 20%, but in the temperature range of 885 ~ 1195 ℃ change is very small, which gives cold drawn seamless steel pipe production to control the lateral deformation of metal The convenience.
