Thick-walled steel pipe thick-walled steel pipe seamless steel pipe manufacturing process:
Hot rolling (extruded seamless steel pipe) round billet → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → pigging → sizing (or variable diameter) cooling → straightening → hydraulic test (or flaw detection) mark →Storage.
The raw material for seamless steel pipe rolling is a round tube blank. It is sent to the furnace for heating through a conveyor belt. The billet is fed into a furnace and heated to about 1200 °C. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. After the round tube blank is released, it is perforated by a pressure punch.
The more common puncher is a tapered roller press. The machine has high production efficiency, good product quality, large perforation diameter and can wear a variety of steel types. After the round blank is perforated, it is continuously rolled, rolled or extruded by three rolls. After extrusion, the tube should be sized. The sizing machine is screwed into the steel core at a high speed by a conical drill bit to form a steel pipe. The inner diameter of the steel pipe is determined by the outer diameter of the sizing machine drill bit. After the steel pipe is sized, it enters the cooling tower and is cooled by water spray. After the steel pipe is cooled, straightening is performed. After the steel pipe is straightened, it is sent to the metal flaw detector (or hydraulic test) by the conveyor belt for internal flaw detection. If there is a crack inside the steel pipe, bubbles and other problems will be detected. After the quality inspection of the steel pipe, it must be carefully selected by hand. After the quality inspection of the steel pipe is qualified, the paints such as the spray number, specifications, production batch number, etc. are hoisted into the warehouse by crane.