Technology of Seamless Steel Tube Production

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General seamless steel tube production process can be divided into cold drawing and hot rolled, cold rolled seamless steel tube production process generally more complicated than hot rolled.
Three-roll rolling tube billet must first, after the extrusion sizing test, if there is no response after crack on the surface of pipe have to be cut after cutting machine, cutting grow about a meter of billet.And then enter the annealing process, annealing with acid pickling liquid, pickling when should pay attention to whether there is a lot of bubble surface, if there is a lot of bubbles show that the quality of the steel tube can not meet the corresponding standards.Appearance on cold rolled seamless steel tube is shorter in hot rolled seamless steel pipe, cold rolled seamless steel tube wall thickness generally smaller than hot rolled seamless steel tube, but the surface looks brighter than the thick ASTM A106 seamless steel pipe , not a lot of rough surface, the diameter is not a lot of burr. The delivery condition of hot rolled seamless steel tube is usually made after heat treatment.Hot-rolled seamless steel tube after QC should pass staff strict manual pick, after the quality inspection for surface coating of oil, and then followed by cold drawing experiment many times, perforation of the experiments conducted after hot rolling processing, if the punched hole diameter is too large for straightening straightening.After straightening, the transmission device is transmitted to the detector to carry out the test, and then the label and the specification are put into the warehouse.
Circular tube billet and heating to punch, three-roll skew rolling, rolling, or pressing - pipe - sizing (or reducing) - cooling - straightening to hydrostatic test or inspection - > tag, warehousing seamless steel tube is made from solid tube ingot or the perforation capillary, then through hot rolling and cold rolling or cold dial.The specification of seamless steel tube is indicated by the outer diameter of the wall thickness millimeter. Generally greater than 32 mm hot rolled seamless steel tube diameter, wall thickness 2.5 200 mm, to 6 mm cold rolled seamless steel tube diameter, wall thickness to 0.25 mm, to 5 mm thin wall pipe diameter thickness less than 0.25 mm, cold than hot rolled high dimensional accuracy.
It is usually made from the high quality carbon steel, such as 10, 20, 30, 35, 45, etc., such as low alloy steel, such as 16Mn, 5MnV, etc., etc., which are made of hot rolled or cold rolled steel, such as 40Cr, 30CrMnSi, 45Mn2, 40MnB, etc.The seamless pipe made by low carbon steel, such as 10 and 20, is mainly used for flow pipe.The seamless work of medium carbon steel such as 45 and 40Cr is used to make mechanical parts, such as car and tractor parts.Generally use seamless steel tube to ensure strength and flattening test.Hot rolled steel pipe in hot rolled state or heat treatment.Cold rolled with heat treatment. Hot rolled, as the name implies, the temperature of the rolling piece is high, so the deformation resistance is small, can achieve 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.
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