Research progress on liquation cracking of precipitation hardened nickel-based superallloys in fusion welding

Precipitation hardened nickel-based superalloys are widely used in aero and industrial gas turbine engines due to their excellent high temperature strength and hot corrosion resistance. However,the components’ life and performance will be affected because of its high liquation cracking susceptibility during welding. The formation mechanism of liquation cracking of precipitation hardened nickel-based superallloys in fusion welding is introduced systematically. Several methods for controlling liquation cracking are introduced,including increasing heat input,pre-weld preheating,pre-weld heat treatment and adding filler alloys. At last,the main future research directions are pointed out.