Seamless stainless steel pipes, also known as stainless steel seamless pipes, are made of steel ingots or solid tubes through perforation to form rough pipes, and then hot rolled, cold rolled or cold drawn.
1. Different pipe making processes.
Seamless stainless steel pipes, also known as stainless steel seamless pipes, are made of steel ingots or solid tubes through perforation to form rough pipes, and then hot rolled, cold rolled or cold drawn.
Stainless steel welded pipes are made of stainless steel plates.
2. Weld seams.
Decorative 304 stainless steel welded pipes have weld seams due to the pipe making process, but seamless steel pipes, like its name, have no weld seams. Good quality decorative stainless steel welded pipes have all weld seams protected by nitrogen.
3. Thickness.
The raw steel strips of stainless steel welded pipes are all rolled and have a relatively uniform thickness. The finished specifications of welded pipes have thin and thick pipes. However, the thickness of stainless steel seamless pipes is often uneven, and they are all relatively thick pipes.
4. Welding performance.
Under normal circumstances, there are certain differences in the chemical composition of general 304 seamless stainless steel pipes and seamless stainless steel pipes. The steel composition of seamless stainless steel pipes only meets the basic requirements of ASTM. As for the steel used to produce welded stainless steel pipes, it contains chemical components suitable for welding, such as silicon, sulfur, manganese, oxygen and ferrite, which can be mixed in a certain proportion to produce a weld melt that is easy to transfer heat during welding, so that the entire weld is welded through. However, due to the lack of the above elements, seamless stainless steel pipes will produce various unstable factors during welding, making it difficult to weld firmly and not weld through.
4. Corrosion resistance.
Under normal circumstances, the corrosion resistance of two stainless steel pipes and seamless pipes of the same material is basically the same.
5. Price.
The price of seamless steel pipes is higher than that of welded stainless steel pipes.
6. Comprehensive quality
Generally speaking, the quality of 304 seamed stainless steel pipes is better than that of seamless stainless steel pipes. This is because welded stainless steel pipes are made of precise cold-rolled plates that have been inspected and passed, so the defects are basically at the welding point. 304 seamless stainless steel pipes are made of stainless steel billets punched by punches, resulting in many tearing phenomena in the pipe wall formed by extrusion. According to eddy current testing, the defective rate of seamless stainless steel pipes is usually lower than that of seamless stainless steel pipes.
6. Surface.
The surface requirements of seamless pipes are not strict, and there will be less obvious spots. The surface treatment requirements of decorative stainless steel pipes are more stringent.
7. Application.
Seamless pipes are mainly industrial pipes. Decorative pipes are widely used, mainly in the field of decorative welding, but as the process of decorative stainless steel pipes becomes better and better, thick-walled decorative pipes will also replace some seamless steel pipes.
