Stainless steel pipe is a kind of hollow round steel, which is widely used in petroleum, chemical industry, medical treatment, food, light industry, mechanical instrument and other industrial conveying pipes and mechanical structural parts. At the same time, it is also widely used in the manufacture of mechanical parts and engineering structures. Stainless steel pipe is divided into seamless stainless steel pipe and welded stainless steel pipe, they mainly have the following similarities and differences:
ASTM A312 TP316L seamless steel pipes
Differences between seamless stainless steel pipe and welded stainless steel pipe:
Difference in process
Stainless steel seamless pipe: the round tube billet after heating,through cold rolling, cold drawing or hot extrusion production process.The thicker the wall thickness of the product, the more economical and practical, the thinner the wall thickness, the higher the processing cost.
Seamless stainless steel tube’s manufacturing process is at 2200° F in the stainless steel billet punched out a hole, at this high temperature, the tool steel after stamping and drawing become soft and spiral shaped out of the hole. The seamless stainless steel tube produced in this way has uneven wall thickness and high eccentricity. The welded stainless steel pipe is made of precise cold-rolled plate, so the welded stainless steel pipe wall thickness tolerance is very small, and the entire circumference of the wall thickness is very uniform.
Stainless steel welded pipe: welded by steel plate or strip after being crimped and formed by the unit and mold.Stainless steel welded pipe can be divided into stainless steel Longitudinal-seam Submerged Arc Welded (LSAW) pipes and stainless steel Spiral submerged arc welding (SSAW) steel pipes by welding method.Stainless steel welded pipe production efficiency, variety and specifications.In addition, welded pipe in the processing process to avoid multiple heating process,and the production process is very environmentally friendly.Stainless steel seamless tube: the round tube billet after heating, through cold rolling, cold drawing or hot extrusion production process.The thicker the product wall, the more economical and practical, the thinner the wall thickness, the higher the processing cost.
Welding performance:
There is a general seam stainless steel pipe and seamless stainless steel pipe chemical composition has a certain difference. Production of seamless stainless steel pipe steel composition is only to meet the basic requirements of ASME. The steel used to make welded stainless steel tubes contains chemicals suitable for wel
ASTM A312 TP304 welded steel pipes
ding. For example, silicon, sulfur, manganese, oxygen and elements such as triangular ferrite can be mixed in a certain proportion during the welding process to produce a weld melt which is easy to transfer heat, so as to make the whole weld penetration. Seamless stainless steel pipe lack of the above several chemical components, it will produce a variety of unstable factors in the welding process, not easy to weld and welding through.
Similarities between seamless stainless steel pipe and welded stainless steel pipe:
Grain size:
The grain size of the metal is related to the heat treatment temperature and the time it takes to maintain the same temperature. The grain size of annealed welded stainless steel pipe is the same as that of seamless stainless steel pipe. If a welded stainless steel tube is treated with minimum cooling, the grain size of the weld will be smaller than that of the metal to be welded, otherwise, the grain size will be the same.
Pipeline strength:
The strength of the pipe depends on the alloy composition, so seamless stainless steel tubes containing the same alloy and the same heat treatment and welded stainless steel tubes are essentially the same strength.
As a professional piping supplier,we can supply seamless stainless steel pipe and welded stainless steel pipe and other pipes,its common materials are 201/304/316L.If you want to know more about our products,please feel free to contact us.Email:sales@haihaogroup.com
