The production process of thick-walled seamless steel pipe:
1. Round tube blank → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → tube removal → sizing (or diameter reduction) → cooling → straightening.
2. Cold drawn (rolled) seamless steel pipe:
Round tube blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → rough tube heat treatment (such as quenching and tempering, normalizing, annealing, etc.) → rough pipe straightening Straight→finishing.
3. Manufacturing process of thermally expanded seamless steel pipe:
Round tube blank→heating→piercing-upsetting-annealing-pickling-oiling-multi-pass cold drawing (cold rolling)-blank straightening-finishing.
4. The production process of hot-rolled seamless steel pipe is the same as that of thermal expansion, except that the size of the hollow capillary tube is smaller.
5. Insert the pipe into the mandrel using the jacking method. After reaching the predetermined length, take out the mandrel.
6. The wire drawing method is to draw the metal wire into filaments through a die.
7. The extrusion method is that the metal bar moves forward under the squeeze of the extruder.
8. There are three commonly used bending methods:
One method is hydraulic bending; the other is mechanical bending; the third is flame bending.
9. Straightening machine The straightening machine is mainly used to check and adjust the straightness and verticality of extra-long steel pipes, and to produce seamless steel pipes at various angles.
10. Chamfer: Curl the steel plate along the outer circumference into a circular shell.
11. Grooving Grooving is to curl the steel plate along the outer circumference into a circular shell.
12. Rolling: Use a tapered core to wrap the edge of the board into a curved surface. Rolling should ensure that the edges are neat and not deformed.
13. Trim the edges. Use special tools to cut the flanges and cut off the iron oxide scale.
14. Polishing: Perform bright solution treatment on the entire flow path of large-diameter spiral welded pipes.
15. Ultrasonic flaw detection shall be carried out item by item according to GB7735 standard.
16. Spraying mark The spraying mark is a mark of the serial number, specification and production batch number sprayed with paint.
