What is Seamless carbon steel pipe?

Seamless carbon steel pipe is made of steel ingot or solid tube made of capillary, and then made of hot-rolled, cold-rolled or cold turntable. Seamless steel pipe plays an important role in carbon steel pipe industry in China. According to incomplete statistics, there are about 240 seamless carbon steel pipe manufacturers in China, about 250 sets of seamless carbon steel pipe plants and an annual production capacity of about 4.5 million tons. From the perspective of caliber, < φ 76, accounting for 35%, and < φ 159-650, accounting for 25%. According to varieties, 1.9 million tons of general-purpose pipes, accounting for 54%. 760000 tons of oil pipes, accounting for 5.7%; 150000 tons of hydraulic props and precision pipes, accounting for 4.3%; 50000 tons of stainless steel pipes, bearing pipes and automobile pipes, accounting for 1.4%.



The raw material of seamless carbon steel pipe is round pipe. The round pipe is cut into rough with a length of about 1 meter by a cutting machine, and heated by a conveyor belt to the furnace. The billet is sent to the furnace for heating at a temperature of about 1200 ℃. The fuel is hydrogen or acetylene. Furnace temperature control is the key problem. After baking the tube through the pressure piercer. Generally, the more common piercer is the tapered roller piercer. The perforator has the advantages of high production efficiency, good product quality, large amount of perforation expansion and wear of various steels. After piercing, the tube has been cross rolled, rolled or extruded by three rollers. After extrusion, remove the pipe diameter. The sizing machine enters the steel embryo drilling hole through the high-speed rotation of the cone bit to form the steel. The inside diameter of the pipe is determined by the outside diameter of the sizing bit. When the diameter of the steel pipe increases, it enters the cooling tower and is cooled by spray cooling, and the steel tube is cooled to straighten it. Adjust the steel through the conveyor belt to the metal detector (or hydrostatic test) for internal test. If there are cracks, bubbles and other problems in the steel pipe, they will be found. Pipeline quality inspection can also be selected by strict manual work. After the quality control of the steel pipe, the number, size, production batch number, etc. And it is hoisted into the warehouse by crane.