Many people think that stainless steel seamless pipe is not much different from the seam pipe, as long as the inner wall of the seam pipe is smooth enough and the overall quality is good enough, you can replace the seamless pipe with a seam pipe. As everyone knows, the difference between stainless steel seamless pipes and welded pipes is more than a little bit of what can be seen by the naked eye, and I will explain it to you today.

1, stainless steel seam pipe and stainless steel seamless pipe chemical composition has a certain difference. The steel composition for the production of seamless pipes only meets the basic requirements of astm. The steel from which the welded pipe is made contains chemicals suitable for welding. For example, the mixture of silicon, sulfur, manganese, oxygen and triangular ferrite in a certain proportion can produce a welding flux that is easy to transfer heat during the welding process, so that the entire weld is welded through. The lack of the above chemical composition of the steel pipe, such as seamless pipe, in the welding process will produce a variety of unstable factors, not easy to weld and welding opaque.

2. The quality of welded stainless steel pipes is better than that of seamless stainless steel pipes. Because the welded stainless steel pipe is made of a precise cold-rolled sheet that has been inspected, any defects are limited to the weld. The seamless pipe is made of stainless steel billet stamped by punch, resulting in many tears in the pipe wall formed by extrusion. Eddy current test shows that the defective rate of welded stainless steel pipe is usually lower than that of seamless stainless steel pipe. Using ultrasonic testing, the background noise of seamless stainless steel welded pipe is so large that it is difficult to find its defects. The background noise of the welded stainless steel pipe is very low, and it is easy to find the defect.

3, stainless steel seamless pipe manufacturing process is at the temperature of 2200°f in the stainless steel billet stamping out a hole, at this high temperature, tool steel by stamping and drawing becomes soft and spirally formed out of the hole. In this way, the wall thickness of the pipe is uneven and the eccentricity is high. The wall thickness difference of a sewn tube is larger than that of a sewn tube. Because the welded stainless steel pipe is made of precise cold-rolled sheet, the wall thickness tolerance of the welded pipe is very small, and the wall thickness is very uniform throughout the circumference.