At present, the requirements of seamless steel pipe are higher, and the requirements of technology are also closely related to production and life. The technical requirements of seamless steel pipe should be shown through production, and the production technology and production process of seamless steel pipe are constantly improving. What are the production methods and methods of seamless steel tubes?

　　According to different production methods, it can be divided into hot-rolled pipe, cold-rolled pipe, cold-drawn pipe, extruded pipe and so on.

　　1. Hot-rolled seamless tubes are generally produced on automatic tube rolling mills. The solid billet is checked and cleared of surface defects, cut into the required length, centered on the end face of the billet perforation, then sent to the heating furnace for heating, and perforated on the perforator. Under the action of the roll and the top, a cavity is gradually formed inside the billet, which is called capillary. It is then sent to the automatic pipe mill to continue rolling. Finally, the wall thickness of the whole machine is equalized, and the sizing machine is used to calibrate the diameter, which meets the requirements of specifications. It is an advanced method to produce hot-rolled seamless steel pipe by continuous pipe rolling mill.

　　2. In order to obtain seamless pipes with smaller size and better quality, cold rolling, cold drawing or combination of the two methods must be adopted. Cold rolling is usually carried out on a two-roll mill. Steel tubes are rolled in an annular pass consisting of a circular groove with variable cross-section and a fixed conical head. Cold drawing is usually carried out on single-chain or double-chain cold-drawing machines of 0.5-100T.

　　3. The extrusion method is to place the heated tube blank in a closed extrusion cylinder, and the perforating rod moves with the extrusion rod to extrude the extruded part from a smaller die hole. This method can produce steel pipes with smaller diameter.