How is Seamless Pipe Made

Seamless pipe is a long steel bar with a hollow section and no joints around it. It is widely used in oil, natural gas, chemical, metallurgy, electric power and other industries. And it is mainly used for conveying fluids and loads. But how is seamless pipe made? Let IBC Group answer this question for you!

Seamless tubes are produced through a specific manufacturing process, and there are three main production methods: hot rolling, cold rolling and extrusion.

1. Hot-rolled seamless pipes are generally produced on automatic tube rolling units. After inspection and removal of surface defects, the solid tube blank is cut to the required length and centered on the perforated end face of the tube blank. The tube billet is then sent to a heating furnace to be heated and perforated on a perforator. At the same time of perforation, the tube blank continues to rotate and advance, under the action of the roll and the head, the tube blank gradually forms a cavity, called the capillary. The tube is then sent to an automatic tube mill to continue rolling. Finally, the wall thickness of the whole machine is adjusted. And then the sizing machine is calibrated to meet the specifications.

2. Cold rolling and cold drawing are the main methods to produce small size and high quality seamless pipes. The former is usually carried out on a two-high mill, in which the steel pipe is rolled in a ring consisting of a variable circular groove and a fixed conical head. The latter is usually carried out on a single or double chain cold drawing machine of 0.5 ~ 100T.

3. The extrusion method is to place the heated tube blank in a closed extrusion cylinder. The perforating rod moves with the extrusion rod to extrude the extruded part from the smaller die hole. And this method can produce steel pipes with smaller diameters.

Performance Profile of Seamless Pipe

1. Excellent material: Seamless pipe can be made of ordinary and high-quality carbon structural steel (such as Q215-A ~ Q275-A and 10 ~ 50 steel), low alloy steel (such as 09MnV, 16Mn, etc.), alloy steel, stainless acid steel and other materials. So it has good corrosion resistance and acid and alkali resistance, can be used in alkali, salt, atmospheric environment and high temperature and other harsh conditions. Does not require regular maintenance, effective life of more than 15 years.

2. Superior mechanical properties: seamless pipe has high tensile strength, its tensile strength is more than 8 to 10 times that of ordinary steel, the elastic coefficient is better than steel. And it has good creep resistance, corrosion resistance and shock resistance. In addition, the seamless pipe also has good mechanical properties and easy processing, can be reused on mechanical equipment, no memory, no deformation, and has anti-static function.

3. Economic and practical: Seamless pipe has a hollow cross-section, light weight, only one-fifth of the steel, so when transporting fluids, you can save a lot of materials and energy. At the same time, the wall thickness of the seamless pipe can be adjusted according to needs. And the thicker the wall thickness, the higher the economy and practicality.

4. Wide range of uses: seamless pipe is mainly used in petroleum geological drilling pipe, petrochemical cracking pipe, boiler pipe, bearing pipe and high-precision structural steel pipe for automobiles, tractors and aviation. In addition, seamless pipes are also widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel scaffolding used in construction.