According to different forming methods, seamless pipe can be divided into two types: extrusion type and cold drawing type.


1. Hot rolling (extrusion): round billet heating piercing three-roll cross rolling, continuous rolling or extrusion piping sizing (or reducing diameter) cooling straightening hydraulic testing (or flaw detection) marking raw materials of seamless tubes in warehouse are round billets. The round tube billet is cut into billets about 1 m long by a cutting machine and sent to the furnace for heating through a conveyor belt. The billet is fed into the furnace and heated to about 1200 degrees Celsius. Fuel is hydrogen or acetylene. Temperature control is a key problem. After releasing the round billet, it is subjected to through-hole punching machine.


The more common punch is tapered roller punch. The perforator has high production efficiency, good product quality, large perforation diameter, and can grind many kinds of steel. After piercing, the round billet is rolled in turn, rolled or extruded by three rolls. After extrusion, the tube should be finalized. The sizing machine rotates to the steel core at high speed through a conical drill to form a steel pipe. The inner diameter of steel pipe is determined by the outer diameter of drill bit of sizing machine. After the steel pipe is dimensioned, it enters the cooling tower and is cooled by water spray. Straighten the steel tube after cooling. After straightening, the steel pipe is sent to the metal flaw detector (or water pressure test) through the conveyor belt for internal flaw detection. If there are cracks in the steel pipe, bubbles and other problems will be found. After the quality inspection of steel pipes, careful selection must be made by hand. After the quality inspection of the steel pipe, the paint is sprayed with the paint number, specifications, production batch number, etc. It is hoisted to the warehouse by a crane. :


2. Cold drawing: round tube blank heating piercing pressing head annealing pickling oiling (copper plating) multi-pass cold drawing (cold rolling) empty tube heat treatment straightening hydraulic testing (inspection) marking storage.


The difference starts with step four. After the round billet is hollowed out, annealing is needed. After annealing, pickling with special acid liquids. Oil after pickling. The next step is to carry out multi-pass cold drawing (cold rolling) and then special heat treatment. Straighten it after heat treatment. After straightening, the steel pipe is sent to the metal flaw detector (or water pressure test) through the conveyor belt for internal flaw detection. If there are cracks in the steel pipe, bubbles and other problems will be found. After the quality inspection of steel pipes, careful selection must be made by hand. After quality inspection of steel pipe, paint is sprayed with numbers, specifications, batch numbers, etc., and hoisted to warehouse by crane

According to different forming methods, seamless tube can be divided into two types: extrusion type and cold drawing type.


1. Hot rolling (extrusion): round billet → heating → piercing → three roll cross rolling, continuous rolling or extrusion → pipe moving → sizing (or reducing diameter) → cooling → straightening → hydraulic test (or flaw detection) → marking → raw material of seamless tube in warehouse is round billet. The round tube blank is cut into about 1 m long blank by cutting machine, and sent to the furnace for heating by conveyor belt. The billet is fed into the furnace and heated to a temperature of about 1200 ℃. The fuel is hydrogen or acetylene. Furnace temperature control is the key problem. After the round billet is released, it is subjected to a through-hole punch.


The more common punch is the tapered roller punch. The perforator has the advantages of high production efficiency, good product quality, large perforation diameter and various steel grades. After piercing, the round billets are rolled in turn, rolled or extruded by three rolls. After extrusion, the tube shall be shaped. The sizing machine rotates into the steel core at high speed through the conical drill bit to form the steel pipe. The inner diameter of the steel pipe is determined by the outer diameter of the sizing machine bit. After the steel pipe is dimensioned, it enters the cooling tower and is cooled by water spray. After the steel pipe is cooled, it shall be straightened. After the steel pipe is straightened, it is sent to the metal flaw detector (or water pressure test) through the conveyor belt for internal flaw detection. If there are cracks inside the steel pipe, bubbles and other problems will be found. After the quality inspection of steel pipes, they must be carefully selected by hand. After the quality inspection of the steel pipe, spray the paint with the number, specification, production batch number, etc. And use a crane to lift it into the warehouse. :


2. Cold drawing: round tube blank → heating → piercing → pressing head → annealing → pickling → oiling (copper plating) → multi pass cold drawing (cold rolling) → empty tube → heat treatment → straightening → hydraulic test (inspection) → marking → storage.


The difference starts with step four. After the billet is hollowed out, annealing needs to be started. After annealing, pickling with special acid liquid. After pickling, apply oil. The next step is to carry out multi pass cold drawing (cold rolling) on the empty tube, and then carry out special heat treatment. After heat treatment, straighten it.  After the steel pipe is straightened, it is sent to the metal flaw detector (or water pressure test) through the conveyor belt for internal flaw detection. If there are cracks inside the steel pipe, bubbles and other problems will be found. After the quality inspection of steel pipes, they must be carefully selected by hand. After the quality inspection of the steel pipe, the paint shall be sprayed with the number, specification, production batch number, etc., and hoisted to the warehouse by crane.