seamless steel tube

Seamless steel pipe is a kind of long steel with hollow section and no joints around. Seamless steel pipe has a hollow section and can be used as a pipeline for conveying fluids, such as oil, natural gas, gas, water and some solid materials. Compared with solid steel such as round steel, seamless steel pipe is lighter in weight when its bending and torsional strength is the same. It is a kind of economic section steel, which 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. Manufacturing ring-shaped parts with seamless steel pipes can improve the material utilization rate, simplify the manufacturing process, and save materials and processing hours, such as rolling bearing rings, Jack sleeves, etc., which are widely manufactured with steel pipes. Steel pipe is also an indispensable material for various conventional weapons. The barrel and barrel of the gun should be made of steel pipe. Steel pipe can be divided into round pipe and special-shaped pipe according to the shape of cross-sectional area. Because the circular area is the largest under the condition of equal perimeter, more fluid can be transported with a circular tube. In addition, when the ring section is subjected to internal or external radial pressure, the force is more uniform. Therefore, the vast majority of steel tubes are circular tubes. However, circular pipes also have certain limitations. For example, under the condition of plane bending, the bending strength of circular pipes is not as strong as that of square and rectangular pipes. Square and rectangular pipes are commonly used in the framework of some agricultural machines and tools, steel and wood furniture, etc. Special shaped steel pipes with other cross-section shapes are also required for different purposes.

Welded steel pipe

Welded steel pipe, also known as welded pipe, is a steel pipe made of steel plate or steel strip after crimping and forming. Welded steel pipe has the advantages of simple production process, high production efficiency, many varieties and specifications and less equipment investment, but its general strength is lower than that of seamless steel pipe. Since the 1930s, with the rapid development of high-quality strip continuous rolling production and the progress of welding and inspection technology, the weld quality has been continuously improved, the variety and specification of welded steel pipes have been increasing, and seamless steel pipes have been replaced in more and more fields. Welded steel pipes are divided into straight seam welded pipe and spiral welded pipe according to the form of weld.