Alloy steel pipe is mainly used for high-pressure and high-temperature pipelines and equipment such as power plants, nuclear power, high-pressure boilers, high-temperature superheaters and reheaters. It is made of carbon steel, alloy structural steel and stainless heat-resistant steel, and is made by hot rolling (extrusion, expansion) or cold rolling (drawing).
Alloy pipes have hollow cross-sections and are widely used as pipelines for conveying fluids, such as pipelines for conveying oil, natural gas, coal gas, water and certain solid materials. Compared with solid steel such as round steel, alloy steel pipes are lighter in weight when the bending and torsional strengths are the same. Alloy steel pipes are an economical cross-section steel and are widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycle frames, and steel scaffolding used in construction. Using alloy steel pipes to manufacture annular parts can improve material utilization, simplify manufacturing processes, save materials and processing time, such as rolling bearing rings, jack sleeves, etc., which are currently widely made of steel pipes. Alloy steel pipes are still indispensable materials. Gun barrels and cannon barrels are made of steel pipes. Alloy steel pipes can be divided into round pipes and special-shaped pipes according to the different cross-sectional shapes. Since the circular area is larger under the condition of equal circumference, more fluid can be transported by using a round pipe. In addition, when the circular cross section is subjected to internal or external radial pressure, the force is more uniform. Therefore, most steel pipes are round pipes.
