Difference and application of seamless hot rolled pipe and cold drawn pipe in seamless steel tube
The general production of hot-rolled seamless steel pipe in the automatic tube rolling mill. Solid billet after inspection and clearance of surface defects, cut into required length, in the tube hole end surface of centering, then sent to a heating furnace, in punch in punch. While continuing to rotate and advance, in the roll and immediate action, tube gradually form a cavity, called capillary. Sent to the automatic tube rolling mill on rolling. Finally after all the entire thickness, sizing machine sizing, achieve specifications. Using continuous pipe mill production of hot-rolled seamless steel tube is advanced.1.2, in order to obtain smaller size and better quality of seamless tube, cold rolling, cold drawing must be used or combined method of cold rolling. Usually in two roller mill, rolling ring groove tapered plug pipe in variable cross section circular slot and the composition. Drawing is usually in single or double 0.100T chain drawbench.1.3, the extrusion method will soon heat the tube blank in the closed extrusion cylinder, the perforation bar and extrusion rod movement, so that extrusion parts from the smaller die hole extrusion. This method can produce smaller diameter steel pipe
type3.1, seamless steel pipe according to the different production methods can be divided into hot-rolled pipe, cold rolled tube, cold drawn tube, extrusion tube and so on3.2, according to the shape of the classification of circular tubes, special-shaped tubes of the division, except the square tube and rectangular tube, there are elliptical tube, semicircle tube, triangle tube, hexagonal tube, convex shaped tube, plum shaped tube and so on3.3, according to the different material, divided into ordinary carbon structure tube, low alloy structure tube, high quality carbon structure tube, alloy structure tube, stainless steel tube and so on3.4, according to special use, there are boiler tubes, geological pipes, oil pipes and so on
purpose2.1 seamless tubes are widely used. General purpose seamless tubes are rolled from plain carbon structural steel, low-alloy structural steel or alloy structural steel, with the most output and are used primarily as pipes or structural parts for conveying fluids2.2, divided into three kinds according to the supply of different uses: the supply of a, according to the chemical composition and mechanical properties; the supply of B, according to the mechanical properties; the supply of C, according to the hydraulic pressure test. According to a, the B class steel supply, such as for under fluid pressure, but also to the pressure test.2.3. Seamless tubes for special purposes include seamless tubes for boilers, seamless tubes for geology, and seamless pipes for petroleum use
