Different forming methods can divide seamless steel pipes into extruded seamless steel pipes and cold drawn seamless steel pipes. The following Wuxi seamless steel pipe manufacturers will share with you what is the forming method of seamless steel pipes?
1. Hot rolling (extruded seamless steel pipe): round tube billet → heating → piercing → three-roll cross rolling, continuous rolling or extrusion → pipe removal → sizing (or reducing) → cooling → straightening → hydraulic test (Or flaw detection)→mark→the raw material of the warehousing rolling seamless tube is a round tube blank. The round tube blank is cut by a cutting machine into a blank of about 1 meter in length and sent to the furnace for heating via a conveyor belt. The billet is fed into the furnace and heated at a temperature of approximately 1200 degrees Celsius. The fuel is hydrogen or acetylene. The temperature control in the furnace is a key issue. After the round tube is out of the furnace, it must be pierced through a pressure punching machine.
Generally, the more common piercing machine is a tapered roller piercing machine. This type of piercing machine has high production efficiency, good product quality, large perforation diameter expansion, and can penetrate a variety of steel grades. After piercing, the round tube billet is cross-rolled, continuously rolled or extruded by three rolls. After squeezing, take off the tube and calibrate. The sizing machine rotates at a high speed through a tapered drill bit into the steel blank to punch holes to form a steel pipe. The inner diameter of the steel pipe is determined by the length of the outer diameter of the drill bit of the sizing machine. After the steel pipe is sizing, it enters the cooling tower and is cooled by spraying water. After the steel pipe is cooled, the pipe must be straightened. 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 are cracks, bubbles, etc. inside the steel pipe, it will be detected. After the quality inspection of steel pipes, strict manual selection is required. After the quality inspection of the steel pipe, paint the serial number, specification, production batch number, etc. with paint. It is hoisted into the warehouse by a crane. :
2. Cold drawn (rolled) seamless steel pipe: round tube blank → heating → piercing → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening →Hydraulic test (flaw detection)→Mark→Warehousing. The rolling method of cold drawn (rolled) seamless steel pipe is more complicated than that of hot rolled (extruded seamless steel pipe). The first three steps of their production process are basically the same.
The difference starts from the fourth step. After the round tube blank is emptied, it needs to be headed and annealed. After annealing, use a special acid liquid for pickling. After pickling, apply oil. Then it is followed by multiple passes of cold drawing (cold rolling) and then billeting, and special heat treatment. After heat treatment, the **** must be straightened. 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 are cracks, bubbles, etc. inside the steel pipe, it will be detected. After the quality inspection of steel pipes, strict manual selection is required. After the quality inspection of the steel pipe, paint the serial number, specification, production batch number, etc., and hoist it into the warehouse by a crane.
