Study on FCAW Semi-Automatic Welding Procedure of Girth Weld Joint of Line Pipes

Abstract

This paper investigate the mechanical property and microstructure of girth weldment of Lan Zhou to Cheng Du crude oil pipeline. The welding joint was bottomed by cellulose electrode E6010 and filled and covered by flux-cored wire AWS A 5.29 E71T8-Ni1. According to SY/T 4103-2006, test results show that the selected process parameters and welding method take on outstanding performance .Microstructure of weld joints is acicular ferrite, polygonal ferrite, proeutectoid ferrite and granular bainite, and widmanstaten ferrite dosn’t exsist in heat affected zone(HAZ). Microstrure of the whole weld joint is mainly polygonal ferrite and granular bainite, this is the reason that mechanical properties can meet the Lan Zhou to Cheng Du crude oil pipeline project requirement.