A seamless steel pipe made of a solitary bit of metal without any creases superficially is known as a consistent steel pipe. As per the generation technique, the consistent pipe is partitioned into a hot moved pipe, a virus moved pipe, a virus drawn pipe, an expelled pipe, a top pipe, and so forth. As per the state of the segment, the consistent steel cylinder is partitioned into two sorts: a round shape and an exceptional shape. The formed cylinder has a majority of entangled shapes, for example, a square shape, a curved shape, a triangular shape, a hexagonal shape, a melon shape, a star shape, and a winged cylinder. The greatest distance across is 650mm and the base breadth is 0.3mm. Contingent upon the application, there are thick-walled tubes and flimsy walled tubes. Consistent steel channels are chiefly utilized for oil geographical penetrating funnels,seamless steel pipe supplier breaking funnels for petrochemicals, evaporator tubes, bearing cylinders, and high-accuracy auxiliary steel tubes for vehicles, tractors, and aeronautics.
Production process of seamless steel pipe:
1 Main production process of hot-rolled seamless steel pipe:
Tube blank preparation and inspection →tube billet heating→perforation→rolling tube→steel tube reheating→fixing (reducing) diameter→heat treatment →finishing of finished pipe→finishing→inspection(non-destructive, physicochemical, table inspection)→inbound
2 cold rolling seamless steel pipe main production process:
Blank preparation → pickling lubrication → cold rolling → heat treatment → straightening → finishing → inspection
The production process of general seamless steel pipe can be divided into cold drawing and hot rolling. The production process of cold rolled seamless steel pipe is generally more complicated than hot rolling. The pipe blank must first be rolled in three rolls. Sizing test, if the surface does not respond to the crack, the round tube is cut by a cutter and cut into a blank of about one meter in length. Then enter the annealing process, the acidification should be acid-washed with acid liquid. When pickling, pay attention to whether there is a large amount of foaming on the surface. If there is a large amount of foaming, the quality of the steel pipe will not reach the corresponding standard. The appearance of cold-rolled seamless steel pipe is shorter than that of hot-rolled seamless steel pipe. The wall thickness of cold-rolled seamless steel pipe is generally smaller than that of hot-rolled seamless steel pipe, but the surface looks brighter than thick-walled seamless steel pipe, and the surface is not too It’s rough and there aren’t too many burrs in the caliber.
The delivery status of the hot-rolled seamless steel pipe is generally delivered after the heat treatment in the hot rolled state. After the quality inspection, the hot-rolled seamless steel pipe is subjected to strict manual selection by the staff. After the quality inspection, the surface is oiled, followed by multiple cold drawing experiments, and the perforation experiment is performed after the hot rolling treatment. If the perforation is too large, straightening correction is required. After straightening, the conveyor is sent to the flaw detector for flaw detection experiments, and finally labeled, formatted, and placed in the warehouse.
Round tube billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → pipe removal → sizing → cooling → straightening → hydraulic test → marking → storage seamless steel pipe The steel tube or the solid tube blank is made into a capillary tube by perforation, and then is formed by hot rolling, cold rolling or cold drawing. The specifications of the seamless steel pipe are expressed by the outer diameter * wall thickness in millimeters.
The outer diameter of hot-rolled seamless pipe is generally larger than 32mm, the wall thickness is 2.5-200mm, the outer diameter of cold-rolled seamless steel pipe can reach 6mm, the wall thickness can be 0.25mm, the outer diameter of thin-walled pipe can reach 5mm, the wall thickness is less than 0.25mm, cold Rolling is more accurate than hot rolling.
Generally, the seamless steel pipe is formed by hot-rolled or cold-rolled low-alloy structural steels such as 10, 20, 30, 35, 45 and other high-quality carbon steels such as 16Mn and 5MnV or 40Cr, 30CrMnSi, 45Mn2, and 40MnB. Seamless pipes made of low carbon steel such as 10 and 20 are mainly used for fluid conveying pipes. 45, 40Cr and other medium carbon steel seamless pipes are used to make mechanical parts, such as the force parts of automobiles and tractors. Generally, seamless steel pipes are required to ensure strength and flattening test. The hot rolled steel pipe is delivered in a hot rolled state or a heat treated state; the cold rolling is delivered in a heat treated state.
Hot rolling, as the name suggests, has a high temperature of the rolled piece, so the deformation resistance is small and a large amount of deformation can be achieved. Taking the rolling of the steel sheet as an example, the thickness of the continuous casting blank is about 230 mm, and after rough rolling and finish rolling, the final thickness is 1 to 20 mm. At the same time, due to the small width-to-thickness ratio of the steel plate, the dimensional accuracy requirement is relatively low, and the shape problem is not easy to occur, and the convexity is mainly controlled. For the organization, it is generally achieved by controlled rolling and controlled cooling, that is, controlling the rolling temperature and finishing temperature of the finishing rolling. Round billet → heating → perforation → heading → annealing → pickling → oiling → Multi-pass cold drawing → blank tube → heat treatment → straightening → hydraulic pressure test → marking → storage.