1. The range of wall thickness of
seamless steel tube is relatively wide, small diameter and large wall thickness and large diameter and large wall thickness can be achieved, but in general, the length is limited (only a small number of manufacturers can produce extra long pipes). Relatively thin, can achieve large diameter and small wall thickness and small diameter and small wall thickness. Theoretically, how long is the long coil, welding, how long can the tube produce. Generally speaking, the thicker the more suitable for seamless steel pipe, the thinner the more suitable for welding pipe.
2. In terms of wall thickness uniformity and concentricity,
welded pipe is better than seamless pipe. Because the thickness tolerance of the cold-rolled sheet is relatively uniform, the deformation during the forming process is uniform. However, the weld seams are protruding, and different companies and specifications have different welding height requirements. In special cases, it can be welded before cold drawing or cold rolling; the seamless steel tube rolling process affected by factors such as equipment accuracy, material function, etc., there are problems of uneven thickness and concentricity, but the roundness is better than that of the welded pipe.
3. Function, better uniformity of welded pipe, better surface quality, better function of steel pipe. The uniformity of the function of the cold-rolled sheet is better than that of the pipe, and the welded pipe generally uses online solid solution, heat treatment is uniform, and the function is more stable. But now there are no heat treatment procedures in the low-end welded pipes on the market, so the quality is high low uneven. Seamless steel pipes are sampled from different directions on the same pipe, the functions are different, and some may differ greatly. During the heat treatment of seamless pipes, there are uneven heating and inconsistent cooling rates during the processing of bundled heat pipes.
4. Corrosion resistance is appropriate. After welding, the weld has reached the material requirements. If there is no heat-treated welded pipe, the corrosion resistance will be significantly lower than that of seamless steel pipes.
5. Welded pipe has lower production cost and is more environmentally friendly. A good welded pipe factory can make the factory environment suitable for the electronics factory.
6. Stress is different. Under the same specification conditions, seamless steel pipes are subjected to higher pressure than welded pipes.
7. The price is different. Seamless steel pipes are more expensive than welded pipes, but also have the following characteristics: seamless pipes are suitable for thick-walled pipes, and welded pipes are suitable for thin-walled pipes.
8. The delivery cycle is different. Because the welded pipe is made of stainless steel coil, the processing is relatively simple, so the delivery time is shorter. The seamless steel pipe starts from round steel, and after perforation, it is subjected to multiple cold drawing / cold rolling processes, and then solution annealing and pickling are used to produce the product. The production cycle is longer.
Generally speaking, seamless steel pipe and welded pipe have their own good and bad, it depends on how the user chooses according to his own needs.
