The differences between the ERW steel pipe
( straight seam resistance welding steel pipe) and LSAW steel pipe
(UOE):Straight seam welded steel pipe, according to the welding process, has two kinds: high frequency electric resistance welding and submerged arc welding. UOE is short for straight seam submerged arc welding, and ERW is short for high frequency straight seam resistance welding. Compared with the submerged arc welding, ERW process does not add any welding material in the welding process, weld forming does not go through hot melting state, and just the weld meter goes through recrystallization process, so the chemical composition of forming weld is completely consistent with the base meter.The welded steel pipe is formed after annealing treatment, and the cold stress and welding stress are both improved, so the ERW steel pipe has a better comprehensive mechanical properties.
As it uses cold expanding process, the geometry size of UOE pipe is accurate, Using UOE pipe docking counterpart is of high quality, which ensures the welding quality,and to a certain extent,eliminating part of the internal stress by the expanding process. In addition, the UOE pipe welding mainly uses multiple wire welding wire (3 or 4). With such kind of technology, the line energy is small and degree of impact on the heat affected zone of base material is also small. For the multiple wire welding,the latter wire can have the effect of eliminating stress formed during welding, which improved the mechanical properties of the steel pipe.Parent metal can carry out 100% ultrasonic flaw detection for the steel plate one by one,to satisfy the requirements of high pressure pipeline for the parent metal.
Although the UOE pipe comprehensive performance is better than that of other steel tube, but the high price makes the cash-strapped customers away.