Effect of Filler Metal on Weld Microstructure Properties of X100 Pipeline Steel

The double wire submerged arc welding experiment of X100 pipeline steel was conducted by adopting the automatic submerged arc welding machine and welding thermal simulation testing machine, the changing situation and effect factors of weld zone microstructure properties under different welding process were analyzed, and the influence rule of filler metal on microstructure properties of X100 pipeline steel were studied. The results showed that the weld microstructure prepared by double wire submerged arc welding consist of acicular ferrite, granular bainite and a small amount of proeutectoid ferrite, the microstructure is small, the toughness is better than that of base metal, and the strength needs to be improved. The weld zone microstructure of X100 pipeline steel prepared by welding thermal simulation consist of lath bainite and a small amount of granular bainite, the toughness of weld zone is consistent with the base metal.