Compared with submerged arc welding, high-frequency resistance welded steel pipe (ERW steel pipe) does not add any welding material during welding, weld without hot melt state, just weld metal after recrystallization process, Therefore, exactly the same chemical composition of the base metal and the weld is formed after the annealing treatment after pipe welding, cold stress producing a molding, welding stress are improved, and therefore better mechanical properties ERW steel pipe.
LSAW (UOE steel pipe) uses the cold-expanding process after welding, it is more accurate for UOE steel pipe geometry, using quality UOE steel pipe butt counterparts when good thus ensuring the quality of welding, pipe expansion process to a certain extent by eliminating the part of the internal stress. UOE steel pipe welding using multi-wire welding (three wire, four-wire), line energy generated during the welding process such as welding small, the impact on base metal heat affected zone is small. Multi-wire welding, after welding wire for front-stress may play a role in the elimination of welding, and thus improved mechanical properties of the steel pipe.
Post time: Dec-10-2019