Effect of linear friction welding process on microstructure evolution, mechanical properties and corrosion behavior of GH4169 superalloy

Linear Friction Welding (LFW) technology was used to realize the welding of GH4169 superalloy, and the effect of welding parameters on the microstructure, mechanical properties and corrosion behavior of the joint was analyzed. The results show that there is a positive correlation between the weld hardness and the tensile strength. With the gradual increase of heat input and welding pressure, the joint quality is gradually improved, but the heat affected zone is not significantly increased. The smaller the grain size of the weld, the higher the strength and plasticity of the joint. With the increase of the joint shortening amount, the corrosion resistance of the weld first gradually increases. However, when the shortening reaches a certain level, the corrosion resistance of the joint becomes little changed. With the increase of solution temperature, the corrosion current density increases and the polarization impedance decreases. The higher the corrosion temperature, the worse the corrosion resistance of the joint. There is no significant correlation between the joint strength and the corrosion resistance. The corrosion resistance of the joint can be enhanced without changing the joint mechanical properties by reducing the welding frequency and amplitude or increasing the welding pressure.