Although hot-rolled steel pipe is also a kind of steel pipe, it still has many irreplaceable advantages compared with ordinary products. For example, it can refine the grains of steel by destroying the casting structure of steel ingots, eliminate microstructure defects, and make steel have good mechanical properties. Specifications also help to meet the different needs of consumers, so that everyone can have a high level of product service.

1. The difference between hot-rolled steel pipe and cold-rolled steel pipe

①Cold-rolled seamless steel pipes are mostly small-caliber, and hot-rolled seamless steel pipes are mostly large-caliber.

②The precision of cold-rolled seamless steel pipe is higher than that of hot-rolled seamless steel pipe, and the price is also higher than that of hot-rolled seamless steel pipe.

③Hot-rolled seamless pipes are divided into ordinary steel pipes, low and medium pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes.

④ In addition to general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes and other steel pipes, cold-rolled (dial) seamless steel pipes also include carbon thin-walled steel pipes and alloy thin-walled steel pipes. , Stainless steel thin-walled steel pipe, special-shaped steel pipe.

⑤In addition to general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes and other steel pipes, cold-rolled (dial) seamless steel pipes also include carbon thin-walled steel pipes and alloy thin-walled steel pipes. , Stainless steel thin-walled steel pipe, special-shaped steel pipe.

2. Hot-rolled steel pipe produces residual stress
Hot rolled steel only develops force when it cools. If the hardness of the rolled piece is cooled with water, the hardness will increase. If it is a chemical problem, fine cracks will appear on the surface of the rolled piece, especially in localized areas. There is no specific change, but there will be a pulling back force, a pulling force between the crystals, so the residual force is the tensile stress.

Hot-rolled steel, hot-rolled steel is softened at a temperature higher than the recrystallization temperature of the alloy, and then pressed into a thin plate or billet section with a pressure roller to deform the material, but the physical properties of the material will not change.

3. The difference between hot rolled steel pipe and welded steel pipe
① From the appearance point of view, the difference between seamless steel pipe and welded steel pipe is that the inner wall of the welded pipe has welding ribs, while the seamless steel pipe does not.

②The pressure of the seamless pipe is relatively high, and the welded pipe is generally around 10 MPa. Now the welded pipe is seamless.

③ The seamless steel pipe is formed at one time during the rolling process. Welded steel pipes require roll welding, generally spiral welding and straight welding. The performance of seamless pipe is better, of course, the price is also higher.

Steel pipe is a hollow long strip of steel that is widely used as a pipeline for transporting fluids, such as oil, natural gas, water, gas, steam, etc. In addition, when the bending and torsional strength are the same, the weight is lighter, so it is also widely used. Used in the manufacture of mechanical parts and engineering structures. It is also commonly used in the production of various conventional weapons, barrels, shells, etc.

Hot-rolled steel pipes belong to the category of seamless steel pipes. Compared with cold-rolled (dial) seamless steel pipe, its mechanical properties are better, it is suitable for the needs of some special fields, and it can also play a very good role in use.