---

Seamless steel pipe has hollow section and is widely used as pipeline for conveying fluid, such as pipeline for conveying oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, steel pipe has the same bending and torsional strength and light weight. It is an economic section steel. It is widely used to manufacture structural parts and mechanical parts, such as oil drill pipe, automobile transmission shaft, bicycle frame and steel scaffold used in construction. Using steel pipe to manufacture ring parts can improve material utilization and simplify manufacturing processes, Save materials and processing time, such as rolling bearing ring, jack sleeve, etc. steel pipe has been widely used to manufacture. Steel pipe is also an indispensable material for all kinds of conventional weapons. Gun barrel and barrel should be made of steel pipe. Steel pipe can be divided into round pipe and special-shaped pipe according to different cross-sectional area and shape. Because the circular area is the largest under the condition of equal circumference, more fluid can be transported by circular pipe. In addition, when the ring section is subjected to internal or external radial pressure, the force is more uniform. Therefore, most steel pipes are round pipes.
However, the circular pipe also has certain limitations. For example, under the condition of plane bending, the bending strength of the circular pipe is not as strong as that of the square and rectangular pipe. Square and rectangular pipes are commonly used in the framework of some agricultural machines and tools and steel and wood furniture. Special shaped steel pipes with other section shapes are also required according to different purposes.

---

Previous: Study on basic theory of cross rolling of seamless steel pipe
Next: Galvanizing method of seamless steel pipe

---