Production method
High-frequency straight seam welded pipe process: Select strip steel that meets the API 5L L360 standard, and use a forming machine to gradually bend the strip steel into the prototype of a straight seam steel pipe. In this process, the bending radius and angle are precisely controlled to ensure dimensional accuracy. Subsequently, the heat generated by the high-frequency current is used to weld the steel pipe joints. During welding, the high-frequency current, welding speed, electrode pressure and other parameters are carefully set to ensure the quality of the weld. After welding, the weld is cleaned, polished and the excess height is controlled to make the surface smooth and flat. Then, the sizing machine and straightening machine are used to improve the dimensional accuracy, roundness and straightness of the steel pipe respectively. Finally, ultrasonic testing, X-ray testing and other means are used to perform non-destructive testing on the weld and the parent material, and the steel pipe is cut as required and further processed according to needs.
Submerged arc welding straight seam steel pipe process: Using steel plate as raw material, first conduct full plate ultrasonic inspection to ensure that the steel plate has no internal defects. Then use the milling machine to double-sided milling of both edges of the steel plate to achieve the specified plate width, plate edge parallelism and groove shape. Then use the pre-bending machine to pre-bend the plate edge. On the JCO forming machine, half of the steel plate is pressed into a "J" shape, and the other half is pressed into a "C" shape, and finally an "O" shape is formed. After that, the weld is pre-welded to fix the weld, and then longitudinal multi-wire submerged arc welding is used to weld the inside and outside of the steel pipe respectively to make the weld more firm and uniform. After welding, the weld and the parent materials on both sides are ultrasonically and X-rayed, and then the full length of the steel pipe is expanded to optimize the dimensional accuracy and internal stress distribution. After that, a water pressure test is carried out to ensure strength and sealing, and the pipe end is processed and inspected again to ensure that the quality of the pipe end meets the standard.
Application field
L360 straight seam steel pipe is widely used in the transportation system in industrial fields such as oil and natural gas. Due to its high strength and good corrosion resistance, it can withstand high pressure and temperature conditions, so it plays an important role in pipeline transportation, oil fields, natural gas extraction, etc. In addition, due to its excellent anti-corrosion performance, L360 straight seam steel pipe is also widely used in marine engineering and chemical equipment.
