A seamless steel tube is made of a steel ingot or solid tube that is perforated into a capillary and then is made of hot rolled, cold rolled or cold. The specification of seamless steel tube is indicated by the outer diameter of the wall thickness millimeter.
Seamless steel tube and cold rolled (dial) seamless steel tube two kinds. Hot-rolled seamless steel tube general steel pipe, low and medium pressure boiler pipe, high pressure boiler tube, alloy steel, stainless steel pipe, oil cracking pipe, geological steel pipe and other steel pipe and so on. Cold-rolled (dial) seamless steel tube in addition to general steel tube, low medium pressure boiler pipe, high pressure boiler tube, alloy steel, stainless steel pipe, oil cracking pipe, steel pipe, other include carbon thin wall steel tube, alloy thin wall steel pipes, thin-walled stainless steel tube, steel tube.
Generally greater than 32 mm hot rolled seamless steel tube diameter, wall thickness 2.5 75 mm, to 6 mm cold rolled seamless steel tube diameter, the thickness of the wall thickness can reach 0.25 mm, to 5 mm thin wall pipe diameter thickness less than 0.25 mm, cold than hot rolled high dimensional accuracy.
As the name implies, the temperature of the rolling piece is high, so the deformation resistance is small, can realize the large deformation quantity. Take the rolling system of steel plate as an example, the thickness of the continuous casting billet is about 230mm, and the thickness is 1 ~ 20mm after roughing and rolling. At the same time, because the thickness of steel plate is smaller than small, the dimension accuracy requirement is relatively low, the plate type problem is not easy to appear, the control convexity is given priority to. For organizations have requirements, generally by controlled rolling cold, open rolling by control of the finishing temperature, finishing temperature and coiling temperature to control the microstructure and mechanical properties of strip steel.