The Definition And Classification Of Steel Tube And Pipe

The Definition and Classification of Steel Tube and Pipe

Steel pipe is a hollow steel strip, a large number the pipe is used for conveying fluid, such as oil, natural gas, water, gas, steam, etc., in addition, while with the same bending and torsional strength, the weight is lighter, so is widely used in the manufacture of machinery parts and engineering structures. And it is also commonly used for the production of various kinds of conventional weapons, barrel, shells, etc.

The classification of steel pipe: steel pipe can be divided into two kinds: seamless steel pipe and welded steel pipe (tube). According to the cross section shape and can be divided into circular tube and special-shaped tube, and the circular steel tube is widely used, but there are some square, rectangle, semicircle, hexagonal, equilateral triangle, octagonal special-shaped steel tube. For fluid under pressure, the steel pipe should have hydraulic experiment to test the compression ability and the quality. Under the pressure of regulation does not leak, soaked or expansion, that will be the qualified pipe, some steel pipe according to the standard or the buyer requires, edge test, flaring test, flattening test, etc. should be have.

Seamless steel pipe: seamless steel tube is made from solid tube ingot or the perforation capillary, then through hot rolling and cold rolling or cold dial. The wall thickness of the seamless steel tube is represent by diameter * thickness. The seamless steel pipe can be divided into hot rolling and cold rolling (dial) seamless steel tube. Hot-rolled seamless steel tube includes general steel pipe, low and medium pressure boiler pipe, high pressure boiler tube, alloy steel, stainless steel pipe, oil cracking pipe, geological steel pipe and other steel pipe and so on. Cold-rolled (dial) seamless steel tube in addition to general steel tube, low medium pressure boiler pipe, high pressure boiler tube, alloy steel, stainless steel pipe, oil cracking pipe, steel pipe, also include carbon thin wall steel tube, alloy thin wall steel pipes, thin-walled stainless steel tube, steel tube. Generally, hot rolled seamless steel tube diameter is greater than 32mm, wall thickness 2.5-75mm, cold rolled seamless steel tube can be to 6mm in diameter, wall thickness to 0.25mm, and the thin wall pipe diameter can be to 5 mm and less than 0.25mm, the dimensional accuracy of cold rolled is higher than hot rolled.

Generally, the seamless steel tube is made of 10, 20, 30, 35 and 45 high quality carbon steel, 16Mn, 5MnV low alloy structural steel or 40Cr, 30CrMnSi, 45Mn2 and 40MnB made from hot rolled or cold rolled steel. Low carbon steel seamless tube made of 10, 20 low carbon steel is mainly used for fluid pipelines. The seamless steel pipe made of 45, 40Cr medium carbon steel seamless pipe is for manufacturing machinery parts, such as the stress of the automobile and tractor parts. Seamless steel pipe used in general need to ensure the strength and the flattening test. Hot-rolled steel pipe with hot rolled or heat treatment state delivery; Cold rolled as heat to heat treatment state delivery.