Abstract:Samples of flash butt welded GH4169 alloy were investigated in this research. Experimental results indicate that redissolution happened to the strengthening phase γ″ and γ′ under the welding heat, so that the strength and microhardness of the weldingSzone are lower than that of the base metal (BM). After solid solution treatment, the strength of the BM is reduced to the same as that of the weldents, the uniform deformation between the welding zone and the BM can be realized during tensile deformation. The 1.2% tensile plastic deformation was carried out before or after solid solution on the weldments respectively, after completing aging heat treatment (720 ℃8 h(60 ℃/h)-620 ℃8 h AC (air cooling)), the tensile results show that a small amount of plastic deformation has little effect on its mechanical properties. After solution-ageingStreatment, the tensile strength of the pre-deformation weldments is similar to that of the BM, but the plastic index is lower, this is related to the coarse grains in the welding zone.