Seamless pipe production

process flow
Tube blank - inspection - peeling - inspection - heating - perforation - acid washing - grinding - lubrication and air drying - welding head - cold drawing - solid solution treatment - acid washing - acid washing passivation - inspection - cold rolling - degreasing - cutting - air drying - internal polishing - external polishing - inspection - identification - finished product packaging
manufacturing process
Hot rolled, cold drawn, hot expanded
According to different production methods, it can be divided into hot rolled pipes, cold rolled pipes, cold drawn pipes, extruded pipes, etc.
1.1. Hot rolled seamless pipes are generally produced on automatic pipe rolling mills. The solid tube blank is inspected and surface defects are removed, cut into the required length, centered on the end face of the tube blank perforation end, and then sent to the heating furnace for heating, and perforated on the perforation machine. During the piercing process, continuous rotation and advancement occur, and under the action of rollers and plugs, a cavity gradually forms inside the tube blank, known as a capillary. Then it is sent to the automatic pipe rolling machine to continue rolling. Finally, the entire machine was evenly adjusted for wall thickness, and the diameter was determined by a sizing machine to meet the specification requirements. The use of continuous pipe rolling mills to produce hot-rolled seamless steel pipes is a relatively advanced method.
1.2. To obtain smaller and better quality seamless pipes, cold rolling, cold drawing, or a combination of both methods must be used. Cold rolling is usually carried out on a two roll rolling mill, where steel pipes are rolled in a circular pass composed of a variable cross-section circular groove and a fixed conical head. Cold drawing is usually carried out on single chain or double chain cold drawing machines with a capacity of 0.5-100T.
1.3. The extrusion method involves placing the heated tube blank in a closed extrusion cylinder, and the perforated rod and extrusion rod move together to extrude the extruded part from the smaller mold hole. This method can produce steel pipes with smaller diameters.