Piercing is the first step of hot-rolled seamless steel pipe deformation, and its role is to solid hollow tube billet dressed as capillary.

Due to wear a capillary surface defects or eccentric (uneven thickness) is difficult to eliminate or reduce the deformation process, therefore, the quality of perforated capillary has a very important impact on the quality of hot-rolled seamless steel pipe. Way pressure tube perforation punching, pushing rotary piercing and piercing. Thick-walled seamless steel mainly used in petroleum geology drilling pipe, petrochemical used in cracking tubes, boiler tubes, pipes and automotive bearings, tractors, aviation and other precision tube structure, its manufacturing process: hot rolled seamless steel tube round → heating → three perforated roll rolling, rolling or extrusion → detached → sizing (or reducing) cooling → straightening → ??hydrostatic test (or testing) logo → storage.

Hot-rolled seamless steel ingot casting can destroy tissue, grain refinement of steel and eliminate defects microstructure, so that the steel dense tissue mechanical properties are improved. This improvement is mainly reflected in the direction along the rolling direction to a certain extent in the steel is no longer isotropic; pouring formed bubbles, cracks and loose, can be welded at a high temperature and pressure.

After hot-rolled seamless steel tube round baked to go through the pressure puncher piercing. Generally more common punch is tapered roller punching machine, punching machine such high production efficiency, product quality, perforated expanding capacity, can be worn a variety of steel. After perforation, round tube has been three-roll rolling, rolling or extrusion. To squeeze off the pipe after sizing. Sizing mill into high-speed rotating cone drill through perforated steel embryo formed steel. Pipe inside diameter is determined by the outside diameter sizing mill drill length.

After sizing the pipe into the cooling tower through spray cooling pipe after cooling, it is necessary to be straightened. After straightening the steel conveyor belt to the metal detection machine (or pressure test) for internal testing. If the internal pipe cracks, bubbles and other issues, will be detected. After the selection of steel but also through strict quality control manual. After the steel quality, spray paint on number, size, batch number and so on. By a crane into the warehouse.