Production process of medium thickness thin walled straight seam high frequency welded pipe

Production process of medium thickness thin walled straight seam high frequency welded pipe:

1. Board test: used to make large diameter submerged arc welded steel pipe straight into the production line, the first full-board ultrasonic test;
2. Milling: through the milling machine on both sides of the steel plate for double-sided milling, so that the required plate width, board parallelism and groove shape;
3. Pre-bending: the use of pre-bending machine for the edge of the pre-bending, so that the board has to meet the requirements of the curvature;
4. Forming: In the JCO forming machine, the first half of the pre-curved steel plate after a number of step into the stamping, pressed into a "J" shape, and then the other half of the same bending steel, pressed into a "C" shape, and finally formed openings Of the "O" shape
5. Pre-welding: the forming of the straight seam welded steel pipe joints and the use of gas shielded welding (MAG) for continuous welding;
6. Internal welding: the use of vertical multi-wire submerged arc welding (up to four silk) in the straight seam steel pipe inside the welding;
7. External welding: the use of vertical multi-wire submerged arc welding in the straight seam submerged arc welded pipe outside the welding;
8. Ultrasonic inspection Ⅰ: straight seam welded steel pipe inside and outside the weld and weld on both sides of the base material 100% inspection;
9. X-ray inspection Ⅰ: 100% of the internal and external welds X-ray industrial television inspection, the use of image processing system to ensure the sensitivity of testing;
10. Expansion: the full length of submerged arc welded pipe to expand the diameter of the steel pipe to improve the dimensional accuracy and improve the distribution of stress in the steel pipe;
11. Water pressure test: the hydraulic pressure testing machine on the diameter of the steel pipe after the root inspection to ensure that the steel pipe to meet the standard requirements of the test pressure, the machine has automatic recording and storage functions;
12. chamfering: the pipe will be qualified after the pipe end processing, to achieve the required pipe end groove size;
13. Ultrasonic test Ⅱ: again by root ultrasonic inspection to check the straight seam welded steel pipe in the expansion, water pressure may produce defects;
14. X-ray inspection Ⅱ: the expansion and water pressure test of the steel pipe after the X-ray industrial TV inspection and tube-side welding film;
15. Tube-side magnetic powder inspection: to carry out this inspection to find pipe end defects;
16. Anti-corrosion and coating: qualified steel pipe according to user requirements for corrosion and coating.