Stainless steel welded pipes and seamless pipes have different chemical compositions. The steel used to produce seamless pipes only meets the basic requirements. In contrast, the steel used for welded pipes contains chemicals suitable for welding.Steel pipes, such as seamless pipes, lacking the aforementioned chemical components will produce various unstable factors during the welding process, making them difficult to weld securely and fully penetrate.

For instance, a mixture of silicon, sulfur, manganese, oxygen, and a certain proportion of troostite can generate a weld melt that is easy to transfer heat during the welding process, enabling the entire weld to penetrate completely.

Seamless stainless steel pipes are made from cold-rolled sheets that have been inspected, so any defects are confined to the welding areas. Seamless pipes, on the other hand, are formed by pressing stainless steel billets through a punch, resulting in numerous tearing phenomena in the tube walls formed by compression. Eddy current testing indicates that the defect rate of seamless stainless steel pipes is typically lower than that of seamless stainless steel pipes. Ultrasonic testing shows that the background noise in seamless stainless steel welded pipes is so high that it is difficult to detect defects. In contrast, the background noise in seamless stainless steel pipes is very low, making it easy to locate defects.

The manufacturing process for stainless steel seamless tubes is2200A hole is pressed into the stainless steel billet at a ° temperature, during which the tool steel becomes soft and spirals out of the hole through pressing and drawing. This results in uneven wall thickness and high eccentricity in the pipe. The wall thickness variation of the seamless pipe is greater than that of the welded pipe. Since stainless steel seamless pipes are made from cold-rolled plates, the tolerance of the wall thickness is very small, and the wall thickness across the entire circumference is extremely uniform.