the seamless steel pipe is made of perforated whole round steel, and the steel pipe without weld seam on the surface is called seamless steel pipe. the seamless steel pipe has a hollow section and is widely used as a pipeline for transporting fluids, such as pipelines for transporting oil, natural g

surface ndt methods of straight seam steel selection principles: magnetic iron pipe should be used in magnetic particle testing; non-ferromagnetic steel should be used in penetration testing. delayed cracking tendency of welded joints, the surface should be non-destructive testing after welding cool

1, tube heatingthe average heating to stop the rapid rise and fall of temperature. to adhere to a smooth landing every time the temperature slowly, the temperature does not exceed the maximum landing 30 ℃.2, mandrel millthe average wall thickness of the thick-walled tubes and solid billets, so that