The seamless steel pipe
and the welded steel pipe
have a weld bead on the inner wall of the welded pipe, and are seamless.
The seamless pipe pressure is higher, the welded pipe is generally about 10 MPa, and now the welded pipe has been seamlessly processed. Seamless steel tubes are formed at one time during rolling.
Welded steel pipes need to be welded after rolling, generally with spiral welding and straight welding.The performance seamless tube is better, and of course the price is higher. The seamless steel pipe is formed by perforating a steel ingot or a solid tube blank, and then hot rolled, cold rolled or cold drawn. The seamless steel pipe has a hollow section and is used in a large amount as a pipe for conveying fluid. A welded pipe is a steel pipe which is welded and deformed into a round shape by a steel strip or a steel plate and has a joint on the surface. The blank used for the welded pipe is steel plate or strip.
Identification method: look inside the pipe, because the outside will be processed, the welded pipe has a gap inside it can be seen, some processing, it is not easy to see, you can slowly touch by hand, or look at the specifications, welded pipe Thinner, the welded pipe is made directly from the machine with a stainless steel
strip (rolled up), and the seamless is a circular steel or tube blank piercing and does not follow the extubation process. The performance is inconsistent in the center line of the seamless steel pipe, the installation of the extruding die is not correct, the opening speed is too fast, the tool is improperly matched, the diameter of the mandrel rod is too large or too small, the deformation is too large, and the mandrel is not fed in time. The quality of the extruding die and the mandrel is not good, including poor finish, low hardness and strength, inconsistent size, incorrect mounting of the carbide mold, etc.;For example, the inclination of the extubation trolley, the mold base or the extubation die itself are not installed correctly on the center frame.