What is the difference between seamless stainless steel pipe and stainless steel welding

There is a difference in the manufacturing process temperature: the manufacturing process of seamless stainless steel pipe is to punch a hole in a stainless steel billet at a temperature of 2200°f. At such a high temperature, the tool steel becomes soft and spirally formed out of the hole by stamping and drawing. The disadvantage of the Stainless Steel Pipe manufactured by such a process is that the wall thickness of the pipe is not uniform and has a high eccentricity, in addition the wall thickness difference of seamless pipe is also greater than that of welded pipe. The stainless steel welded pipe is made of accurate cold-rolled plate, so the manufacturing process will make the pipe wall thickness tolerance is very small, and the wall thickness of the entire circumference is very uniform, which is the reason why the welded pipe is better than the seamless pipe.

In addition, the chemical composition of the two is also different: the steel composition for the production of seamless pipes is only to meet the basic requirements of astm. The steel used in the production of welded pipes contains chemical components suitable for welding, such as silicon, sulfur, manganese, oxygen and a proportional mixture of elements such as delta ferrite, which can produce a welding melt that can easily transfer heat during the welding process in order to make the entire weld weld through. Therefore, the manufacturing process of welded tubes will be more demanding and costly, and the lack of the above chemical composition of the steel pipe, will produce instability, resulting in stainless steel pipe quality problems. Just like seamless pipe, various instabilities will be generated during the welding process, not easy to weld firmly and weld through. So for welded and seamless tubes, we need to understand before it is easy to choose, because the different manufacturing processes and steel requirements will lead to these differences in price, you need to make a judgment when buying.