Production process and technological process of welded steel pipe

　　The welded steel pipe has the advantages of simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded steel pipe is generally higher than that of straight welded steel pipe. It can produce welded steel pipe with larger diameter with narrow blank and different diameter with the same width blank. However, compared with the same length of straight seam pipe, the weld length increases by 30-100%, and the production speed is low.

　　The welded steel pipe with large diameter or thick thickness is generally made of steel blank directly, while the thin-wall welded steel pipe with small welded steel pipe only needs to be directly welded by steel strip. Then after simple polishing, wire drawing is good.

　　Process flow of welded steel pipe

　　Raw material uncoiling - leveling - end shearing and welding - looper - forming - Welding - internal and external weld bead removal - pre correction - induction heat treatment - sizing and straightening - eddy current testing - cutting - hydraulic inspection - Pickling - final inspection (strict control) - Packaging - shipment.

　　The straight welded steel pipe has the advantages of simple production process, high production efficiency, low cost and rapid development. The strength of spiral welded steel pipe is generally higher than that of straight welded steel pipe. It can produce welded steel pipe with larger diameter with narrow blank and different diameter with the same width blank. However, compared with the same length of straight seam pipe, the weld length increases by 30-100%, and the production speed is low.