Influence of recrystallized layer on high cycle fatigue life of directionally solidified superalloy

Using cantilever-rotation-bending method, the influence of recrystallized layer formed by shot peening and heat treatment on high cycle fatigue life of directionally solidified DZ4 superalloy was studied. The results showed that recrystallized layer would formed in the DZ4 superalloy after predeformationg and high-temperature heat treatment, and recrystallized layer would weaken the high cycle fatigue life of DZ4 to a certain extent. In a certain extent of the pressure of shot peening, along with the increase of the pressure of shot peening, the fatigue life was first reduced and after increased.