Study On GH4169 Pulsed Argon Arc Welding Process And Post-weld Heat Treatment

GH4169(Inconel718)is a precipitation-strengthened nickel-based superalloy.The alloy has high thermal sensitivity,poor liquid metal flowability,and is prone to generate harmful Laves phases during welding,resulting in poor weldability.It must be properly heat treated after welding Process to improve joint performance.Pulse argon arc welding(P-TIG)is a new method with controllable heat source suitable for welding metal materials with high thermal sensitivity.Therefore,the pulse argon arc welding process of GH4169 alloy and its post-weld heat treatment process were studied,and the weld seam structure and Performance is important.This article aims at GH4169 alloy plate,using ERNi Cr Mo-3 brand welding wire as filler metal,and uses pulsed argon arc welding method to surfacing welding on GH4169 alloy plate to study the effect of pulsed argon arc welding process parameters on weld forming characteristics and dendrite size law.Secondly,the process parameters of GH4169 alloy pulsed argon arc welding butt welding were optimized,and the structural properties of GH4169 alloy pulsed argon arc welding joint and DC argon arc welding joint were compared and analyzed.Finally,in order to improve the performance of GH4169 alloy and GH4169 alloy pulsed argon arc welding joint,the effects of five different heat treatment processes on the structure and properties of GH4169 alloy and GH4169 alloy pulsed argon arc welding joint were studied.The research results show that increasing the peak current and pulse frequency can refine the weld dendrite spacing.Increasing the base current will cause the dendrite spacing to become larger,while increasing the duty cycle will affect the weld dendrite spacing is not obvious;The optimized pulse argon arc welding process parameters weld GH4169 alloy,the joint strength coefficient can reach 86.6%;compared with GH4169 alloy DC argon arc welding head,GH4169 alloy pulsed argon arc welding head has higher strength and weld width The narrow,weld equiaxed crystal area accounts for a larger proportion,the weld structure is smaller and denser,and the size of the precipitated phase is smaller;the heat treatment process study found that the best heat treatment process for GH4169 alloy is:720℃/8h/FC+620℃/8h/AC,GH4169 welding The best heat treatment process for the joint is: 1020℃/1h/AC+ 720℃/8h/FC+620℃/8h/AC.