HIGH TEMPERATURE LOW CYCLIC FATIGUE BEHAVIOUR OF DIRECTIONALLY SOLIDIFIED Ni-BASE ALLOY DK3
XIE Jizhou; LIU Shaolun; SUN Chuanqi; WU Changxin (Institute of Aeronautical Materials; Beijing)
Cite this article:
XIE Jizhou; LIU Shaolun; SUN Chuanqi; WU Changxin (Institute of Aeronautical Materials; Beijing). HIGH TEMPERATURE LOW CYCLIC FATIGUE BEHAVIOUR OF DIRECTIONALLY SOLIDIFIED Ni-BASE ALLOY DK3. Acta Metall Sin, 1986, 22(5): 63-151.
Abstract The high temperature low cyclic fatigue (LCF) behaviour of a directionally solidified Ni-base alloy DK3 has been studied under strain-controlled and stresscontrolled at 7600℃ in comparison with a conventional cast alloy K3. It was found that for both alloys, their behaviours may be characterized by the conventional stress fatigue curve. The intersections of elastic and plastic lines, so-called "transitional fatigue life", N_T, is absence for alloy DK3 and a little for K3. Under various strain and stress load, LCF life of alloy DK3 is longer than that of K3. When the stress level reduces from 980 to 785 MPa, the difference between the lives of both alloys is about 2 times; when stress level from 685 to 490 MPa, the difference increases more than 3 times.
