Fatigue deformation behavior of FGH96 superalloy under low cycle fatigue loading
Low cycle fatigue failure tests of the powder metallurgical nickel based superalloy FGH96 at 550℃ and 720℃ were carried out under total strain-controlled mode (R=-1).The fatigue failure behaviors were investigated by analyzing cyclic stress response and observing microstructure after fatigue through scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD).The results show that FGH96 superalloy exhibits cyclic stability at 550℃,and cyclic softening afterwards at 720℃ with Δε/2=0.4%,and of cyclic softening at 720℃ with Δε/2=0.7%.After high temperature low cycle fatigue,the γ′precipitates are cuboidal for all samples.No coarsening of γ′ precipitates was detected at 550℃ and at 720℃ with Δε/2=0.4%,but small γ′ precipitates get together to be larger precipitates at 720℃ with Δε/2=0.7%.EBSD shows that the continuous small angle grain boundaries are produced during the fatigue.The small angle grain boundaries have a significant increase at 720℃,especially that case at Δε/2=0.7%.The percent of small angle grain boundaries is 20.6%.
powder metallurgical nickel based superalloy low cycle fatigue fatigue deformation electron backscatter diffraction
GU Yu-li HE Yu-huai LIU Chang-kui TAO Chun-hu
Beijing Institute of Aeronautical Materials,Beijing Key Laboratory of Aeronautical Materials Testing Beijing Institute of Aeronautical Materials,Beijing Key Laboratory of Aeronautical Materials Testing
国际会议
Asia Steel International conference 2012(第五届亚洲钢铁大会)
北京
英文
1-10
2012-09-23（万方平台首次上网日期，不代表论文的发表时间）