YANG Wangyue
,
ZHANG Jishan
,
CHEN Guoliang
,
TIAN Shusen
,
GENG Qingquan Beijing University of Iron and Steel Technology
,
Beijing
,
China. Institute of Metal Research
,
Academia Sinica. Fushun Steel Works
,
Fushun
,
Liaoning
,
China.
材料科学技术（英文）
The deformation and fracture behaviour of nickel-base superalloy GH698 with different grain size have been studied at 700℃ under fatigue-creep interaction conditions. Compared with coarse-grained specimens, the grain refining process shows obvious effect on the mechanical behaviour of the alloy, i. e. in F and C zones, the fraction of pure fatigue and creep fracture on fracture surfaces is greatly reduced, which decreases and increases the fracture life in zones F and C respectively, in FC and C zones, creep deformation is greatly restrained by the alternating stress component, which increases the fracture life remarkably. It is also proved that in spite of the difference in microstru- tures such as grain size, for a constant tem- perature, a unique life equation t_r=A~n can be used to predict rupture life within the stress region controlled by the same fracture mode.
关键词:
Ni-base superalloy
,
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