According to the different production methods of carbon seamless steel tube, hot-rolled pipe, cold-rolled pipe, drawing pipe and extruded pipe can be classified.
1. Hot-rolled seamless tubes are usually produced in automatic rolling mills. Check the solid billet, take it out from the surface defect, cut it into the required length, perforate at the central end of the pipe, then feed it into the heating furnace, and perforate in the heating furnace. Continue to rotate and move while perforating. Under the action of roll and head, cavity is gradually formed in the tube, which is called capillary. Then it is sent to the automatic rolling mill to continue rolling. Finally, according to the sizing machine diameter and specifications to determine the entire machine wall thickness. It is an advanced method to produce hot-rolled seamless steel tube by continuous rolling mill.
2. If we want to get smaller and better quality seamless steel pipe, we must use cold rolling, cold drawing or both. Cold rolling is usually carried out on a twin-roll mill, which rolls in a circular hole formed by a tapered hole and an inactive tapered head. In single-strand or double-strand cold-drawing machines, cold-drawing is usually 0.5 to 100 tons.
3. The extrusion method is to heat the tube into a closed cylinder, extrude the rod and extrude it to extrude the die hole. This method can produce steel pipe with smaller diameter.