How is seamless steel pipe produced?

Seamless steel pipe is made of steel ingot or solid tube blank by perforation, and then made by hot rolling, cold rolling or cold dial. The seamless steel pipe has the important status in our country steel pipe industry. According to incomplete statistics, our country existing seamless pipe production enterprises about more than 240, seamless steel pipe set about more than 250 sets, the annual capacity of about 4.5 million tons. From the diameter < 76, accounted for 35%, < phi 159-650, accounting for 25%. From the perspective of varieties, general purpose pipe 1.9 million tons, accounting for 54%; 760,000 tons of oil pipelines, accounting for 5.7%; 150,000 tons of hydraulic struts and precision pipes, accounting for 4.3%; Stainless pipes, bearing pipes and automobile pipes accounted for 50, 000 tons, accounting for 1.4%.

From: casting order net

The raw material of rolling seamless pipe is the blank of round tube. The blank of round tube will be cut and processed by the cutting machine with a growth of about 1 meter, and sent to the furnace for heating by the conveyor belt. The billet is fed into a furnace and heated at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature control in the furnace is the key issue. After the round tube blank is out of the oven, it must pass through the pressure punch. Generally more common puncher is cone roller puncher, this kind of puncher has high production efficiency, good product quality, large perforation expansion, can wear a variety of steel. After the perforation, the round tube blank is successively rolled by three rolls, continuous rolling or extrusion. After extrusion, pipe sizing should be taken off. Sizing machine through the conical bit high-speed rotation into steel hole, forming steel pipe. The inner diameter of the steel pipe is determined by the outer diameter length of the drill bit of the sizing machine. After the steel pipe is fixed, it enters the cooling tower and is cooled by spraying water. After cooling, the steel pipe will be straightened. After straightening, the steel pipe is sent to the metal inspection machine (or hydraulic test) for internal inspection. If there are cracks, bubbles and other problems inside the steel pipe, it will be detected. Steel pipe quality inspection and strict manual selection. Sprayed with paint after steel pipe quality, number, specification, batch number, etc. And by the crane into the warehouse.