According to different production methods of carbon seamless steel pipe
, hot rolled tubes, cold rolled tubes, drawing tubes, and extruded tubes can be classified.
1.hot-rolled seamless tubes are generally produced in automatic rolling mills. The solid billet is inspected, removed from the surface defects, cut to the required length, perforated at the center end of the tube end, and then fed to a heating furnace where it is perforated. While continuing to rotate and move while perforating, under the action of the roll and the head, a cavity is gradually formed in the tube, which is called capillaries. Then sent to the automatic rolling mill to continue rolling. Finally, the whole wall thickness of the whole machine is determined according to the diameter and specifications of the sizing machine. Continuous rolling mill production of hot-rolled seamless steel pipe is a more advanced method.
2. If you want to obtain smaller and better quality seamless steel tubes, you must use cold rolling, cold drawing or a combination of both. Cold rolling is usually carried out on a two-roll mill, which is rolled in a circular hole formed by a conical hole and an inactive conical head. Cold drawn is usually 0.5 to 100t in single-stranded or double-stranded cold-drawing machines.
3. The extrusion method is to heat the tube in a closed cylinder
, squeeze the rod and squeeze the rod so that it squeezes out in the extrusion die hole. This method can produce smaller diameter steel tubes.