Seamless Carbon Steel Pipe Manufacturing Process

Hot rolling (extruded seamless carbon steel pipe): round pipe perforation → heating → three-roll rolling, rolling or extrusion → separation → sizing (or diameter reduction) → cooling → straightening → hydraulic test (or inspection) → Mark → Inventory.

The raw material is a rolled seamless round tube, and the tube is cut through the growing embryo to a blank of about one meter in the cutting machine, and sent to the furnace by the conveyor belt for heating. The billets are fed into a heating furnace at a temperature of about 1200 degrees Celsius. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. The round pipe puncher is released after the punching pressure. Generally, the more common punch is the tapered roller punch. This kind of punch has high production efficiency, good product quality, strong punching capacity expansion, and can wear all kinds of steel. After perforation, the round tube is three-rolled, rolled or extruded. Extrude the tube after resizing. Sizing and grinding into high-speed rotating taper drills to form steel through perforated billets. The inner diameter of the pipe is determined by the length of the drill bit of the outer diameter sizing machine. After the sizing pipe is cooled and enters the cooling tower through the spray cooling pipe, it needs to be straightened. The steel conveyor belt is straightened and sent to a metal detector (or pressure test) for internal inspection. If there are cracks, air bubbles and other problems inside the pipe, it will be detected. After the steel is selected, it must go through a strict quality control manual. After the quality of the steel is qualified, the paint number, size, batch number, etc. will be sprayed. Access the warehouse by crane.

Cold drawn (rolled) seamless pipe: round pipe perforation → heating → annealing → pickling → oiling (copper) → multi-pass drawing (cold) → billet straightening → heat treatment → hydraulic test (test) → Mark → Inventory.

The rolling method of cold drawn (rolled) seamless steel pipe is more complicated than hot rolled (extruded seamless pipe). Their first three steps are basically the same. The difference is that starting from the fourth step, the round tube is emptied, and then the annealing starts. Special pickling solution should be used after annealing. Oil after marinating. Then after several times of drawing (cold), then the tube blank, special heat treatment. After heat treatment, it must be straightened. The steel conveyor belt is straightened and sent to a metal detector (or pressure test) for internal inspection. If there are cracks, air bubbles and other problems inside the pipe, it will be detected. After the steel is selected, it must go through a strict quality control manual. After the quality of the steel is qualified, the paint number, size, batch number, etc. will be sprayed. Access the warehouse by crane.

Read more : The logistics of seamless steel pipe

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