Seamless steel pipe knowledge introduction
The seamless steel pipe is made of steel ingot or solid tube blank by perforation, and then made by hot rolling, cold rolling or cold drawing. 45 seamless steel pipe is a kind of material in steel, which belongs to high quality carbon structural steel, a large number of The mold production company will use it to make mold steel. The seamless steel pipe is made of high-quality carbon steel or alloy steel, and has hot rolling and cold rolling (drawing) points. The welded steel pipe is formed by welding a steel plate rolled into a tubular shape by a seam or a spiral seam. In terms of the manufacturing method, it is further divided into a welded steel pipe for low-pressure fluid transportation, a spiral-welded electric steel pipe, a direct-wound welded steel pipe, an electric welded pipe, and the like. Seamless steel pipes can be used in various liquids, gas pipes, and the like. Welded pipes can be used for water pipes, gas pipes, heating pipes, etc. From the caliber, <φ76, accounting for 35%, <φ159-650, accounting for 25%. In terms of varieties, general-purpose pipes are 1.9 million tons, accounting for 54%; oil pipes are 760,000 tons, accounting for 5.7%; hydraulic props and precision pipes are 150,000 tons, accounting for 4.3%; stainless steel pipes, bearing pipes and automobile pipes are 50,000 yuan. Tons, accounting for 1.4%.
The raw material for rolling seamless steel pipe is a round tube blank, and the round tube embryo is cut into a blank having a length of about 1 m by a cutting machine, and sent to a furnace for heating through a conveyor belt. The billet is fed into a furnace and heated to a temperature of approximately 1200 °C. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. After the round billet is released, it is subjected to a through-hole punching machine. The more common perforating machine is a conical roller punching machine. This perforating machine has high production efficiency, good product quality, large diameter of perforation and can wear a variety of steel types. After perforation, the round billet is successively rolled, rolled or extruded by three rolls. After extrusion, the tube should be sizing. The sizing machine is rotated at a high speed by a conical drill bit into a steel core 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 has been sized, it enters the cooling tower and is cooled by water spray. After the steel pipe is cooled, it is straightened. After the steel pipe is straightened, it is sent to a metal flaw detector (or water pressure test) by a conveyor belt for internal flaw detection. If there are cracks 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, the paint is sprayed with the number, specification, production batch number, etc. It is hoisted into the warehouse by a crane.
