Seamless steel pipe,made of a piece of metal, the upper surface of the seamless steel pipes. According to the production method, the seamless pipe is divided into a hot rolled pipe, a cold rolled pipe, a cold drawn pipe, an extruded pipe, a top pipe, and the like. According to the shape of the section, the seamless steel tube is divided into two types. A circular shape and a special shape. The shaped tube has a plurality of complicated shapes such as a square shape, an elliptical shape, a triangular shape, a hexagonal shape, a melon shape, a star shape, and a winged tube. The maximum diameter is 650mm and the minimum diameter is 0.3mm. Depending on the application, there are thick-walled tubes and thin-walled tubes. Seamless steel pipes are mainly used as petroleum geological drilling pipes, cracking pipes for petrochemicals, boiler tubes, bearing tubes, and high-precision structural steel tubes for automobiles, tractors, and aviation.
SHANDONG WAN STEEL Import and Export Co., Ltd., is professional steel pipe supplier with more than 30 years experience. We cooperate closely with many large companies at home and abroad, and have set production base in Shandong , Jiangsu,Tianjin , Foshan ect. Our main products are seamless steel pipe, spiral steel pipe, welded steel pipe, hot dipped galvanized steel pipe, precision alloy seamless steel pipe and stainless steel seamless pipe .
the production process of the seamless steel pipe:
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. The sizing test, if the surface does not respond to the crack, the round tube is cut by a cutter and cut into a blank having a length of about one meter. 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 More rough, not too many burrs in the caliber.
Main production process of hot-rolled seamless steel pipe (main inspection process):
Tube blank preparation and inspection →Tube heating→Perforation→Rolling tube→Steel tube reheating→Fixed (reduced) diameter→heat treatment →finished tube straightening→finishing→inspection (non-destructive, physicochemical, Taiwan inspection)→Warehousing.
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 process. If the perforation is too large, straightening correction is required. After straightening, the conveyor is sent to the flaw detector for flaw detection experiments. Finally, the label is placed, the specifications are arranged, and then placed in the warehouse.
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.
cold rolling (drawing) seamless steel pipe main production process:
Blank preparation → pickling lubrication → cold rolling (pull) → heat treatment → straightening → finishing → inspection
The raw material of the cold drawn seamless steel pipe is a hot-pressed steel pipe. After pickling, the scale of the hot-pressed steel pipe is removed and cold chain rolling is performed. And the finished product is a rolled hard roll. Because in the production process, continuous cooling causes the steel pipe to deform and then causes cold work hardening. So that the strength and hardness of the rolled hard roll are increased, and the toughness index is decreased. Therefore, the punching performance is also constantly deteriorating. Hard-rolling can also be used as a raw material for hot-dip galvanizing plants because it can only be used for parts that are simply deformed.
Our products include seamless steel pipes, galvanized steel pipes, spiral steel pipe, etc. And we can meet your individual requirements in terms of quantity and quality. Our products get the ISO9001 quality certificate; French BV, SGS ,China CCS. API; Britain CE certificate, the approval of ISO14000 environmental management system and OSHMS occupational health and safety management system.