The Effect of Welding Material on Weld Microstructure and Properties of Spiral Two-step Welding Pipe

Aim at the problem of L450 steel weld impact property which occurred in mass production spiral two-step welding pipe,using the welding wire with higher contents of Cr,Ni,Ti and other elements to conduct welding,weld sample was taken out through different welding match,the microstructure and mechanical properties were analyzed,the results indicated that the total quantity of proeutectoid ferrite distributed in both sides of column crystal was reduced after replacing welding wire.The weld microstructure mainly included acicular ferrite,the grain of acicular ferrite(AF),proeutectoid ferrite(PF)was finer,its impact toughness value was obviously increased.