The key production process of large-diameter straight seam stainless steel welded pipes is as follows:
1. Plate detection: When the thick steel plate used for manufacturing large diameter Submerged arc welding straight seam steel pipe enters the production line, the full plate ultrasonic detection will be carried out first;
2. Edge milling: According to the edge milling machine, cut both sides of the thick steel plate to achieve the specified width, flatness of the plate edge, and weld appearance;
3. Pre bending edge: Use a pre bending machine to pre bend the edges of the board, so that the edges of the board have a refractive index that meets the requirements;
4. Forming: On the JCO forming machine, the first half of the pre bent thick steel plate is subjected to several stepper motor stamping molds, rolled into a "J" shape, and then the other half of the thick steel plate is bent and rolled into a "C" shape, ultimately producing an open "O" shape.
5. Pre welding: Make the formed straight seam welded steel pipe joint and use gas shielded welding (MAG) to carry out continuous electric welding;
6. Internal welding: longitudinal multi wire Submerged arc welding (up to four wires) shall be used to conduct electric welding on the inner side of straight seam steel pipe;
7. External welding: longitudinal multi wire Submerged arc welding is used to carry out electric welding on both sides of longitudinal Submerged arc welding steel pipe;
8. Ultrasound detection I: Conduct 100% inspection on the internal and external welding of straight welded steel pipes and the butt welds on both sides of the welding;
9. X-ray Inspection I: Conduct 100% X-ray industrial television inspection of internal and external welds, and select image processing system software to ensure the sensitivity of flaw detection detection;
10. Expanding: expand the total length of Submerged arc welding straight seam steel pipe to improve the specification precision of steel pipe and improve the distribution of thermal stress of steel pipe;
11. Pressure test: Conduct individual inspections on the expanded steel pipes on a hydraulic testing machine to ensure that the steel pipes meet the specified experimental working pressure. The equipment has automatic storage and storage functions;
12. Chamfering: Conduct pipe end production and processing on the steel pipes that meet the inspection standards, and achieve the specified pipe end weld specifications;
13. Ultrasonic Testing II: Conduct ultrasonic testing one by one again to check the defects that will be caused by the expansion and pressure of straight welded steel pipes;
14. X-ray Inspection II: Conduct regular X-ray industrial television inspection of steel pipes after expansion and pressure testing, and take photos of pipe end welding;
15. Magnetic Particle Testing of Pipe Ends: Conduct this inspection to detect defects at the pipe end;
16. Corrosion prevention and coating: Steel pipes that meet the standards shall be subject to corrosion prevention and coating according to customer regulations.
If you are interested in our large diameter stainless steel pipes, please feel free to inquire!
