Cracking is one of the common defects of seamless steel pipe. When the seamless steel pipe is quenched, it will also cause cracking of the seamless steel pipe due to improper handling.

Low carbon steel pipe is a carbon steel pipe with a carbon content of less than 0.25%. Due to the low carbon content of low carbon steel and good weldability, it is usually not necessary to take special technological measures to obtain high-quality welded joints. Seamless steel pipes, alloy pipes, low and medium pressure boiler pipes, and oil pipes are mostly low carbon steel pipes.

The raw materials used in ERW steel pipes are hot-rolled coils produced by regular large factories, and the chemical composition and physical properties are relatively stable.Most of the raw materials used in the spiral tube factory are low-grade hot-rolled strip steel, the chemical composition and physical properties are not stable, and there are many internal defects and impurities.

The seamless steel pipe has a hollow section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural gas, gas, water and certain solid materials. Compared with ordinary seamless pipes, stainless steel seamless pipes have higher corrosion resistance, and the finish is better than ordinary seamless steel pipes. But this does not mean that stainless steel seamless pipes will not be corroded.

Stainless steel rectangular pipe is a kind of hollow long steel, which is widely used as pipeline for transporting fluids, such as oil, natural gas, water, gas, steam, etc. In addition, when the bending and torsional strengths are the same, the weight is lighter.Therefore, it is also widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used to produce various conventional weapons, barrels, shells, etc.

Seamless pipe is the most used pipe fitting in oil and gas engineering pipelines and construction engineering pipelines. The pressure rating design of seamless pipe is introduced below. The pressure rating of seamless pipe includes two parts: the nominal pressure rating of standard pipe fittings expressed in nominal pressure. ;Wall thickness class of standard fittings expressed in wall thickness class