Production process of straight seam steel pipe:
1 Plate detection: after the steel plate used to manufacture large-diameter submerged arc welded straight seam steel pipe enters the production line, the whole plate shall be subject to ultrasonic inspection for the first time
2. Edge milling: the two edges of the steel plate are milled on both sides by the edge milling machine to achieve the required plate width, plate edge parallelism and groove shape
3. Pre bending: pre bending the plate edge with a pre bending machine to make the plate edge have the required curvature
4. Forming: on the JCO forming machine, first press half of the pre bent steel plate into & quot; J" The other half of the steel plate is also bent and pressed into & quot; C" Shape, and then form an open & quot; O" Shape. Straight seam steel pipe manufacturer,
5 Pre welding: make the formed straight seam welded steel pipe joint and use gas shielded welding (MAG) for continuous welding;
6. Internal welding: use longitudinal multi wire submerged arc welding (most of them can be four wires) weld on the inner side of the straight seam steel pipe;
7. External welding: weld on the outer side of the straight seam submerged arc welded steel pipe by longitudinal multi wire submerged arc welding;
8. Ultrasonic inspection I: inspect 90% of the internal and external welds of the straight seam welded steel pipe and the base metal on both sides of the weld;
9. X-ray inspection I: inspect 90% of the internal and external welds by X-ray industrial television, using Fig Image processing system to protect the sensitivity of flaw detection; Straight seam steel pipe price, straight seam steel pipe standard, straight seam steel pipe specification,
10 Diameter expansion: the full length of submerged arc welded straight seam steel pipe is expanded to improve the dimensional accuracy of steel pipe, and the actual effect is mainly the distribution state of internal stress in steel pipe
11. Hydrostatic test: inspect the expanded steel pipe one by one on the hydrostatic test machine to protect the steel pipe to meet the test pressure required by the standard. The machine has the function of automatic recording and storage
12. Chamfering: process the pipe end of the qualified steel pipe to meet the required pipe end groove size
13. Ultrasonic inspection II: conduct ultrasonic inspection one by one again to check the possible defects of straight seam welded steel pipe after diameter expansion and water pressure
14. X-ray inspection II: X-ray industrial television inspection and pipe end weld photography shall be carried out for the steel pipes after diameter expansion and hydrostatic test
15. Magnetic particle inspection of pipe end: conduct this inspection to find pipe end defects
16. Performance stabilization and coating: the qualified steel pipe shall be subject to performance stabilization and coating according to the user's requirements. L245 straight seam steel pipe, L450 straight seam steel pipe, X65 straight seam steel pipe manufacturer, X70 straight seam steel pipe manufacturer
