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）
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
,
null
,
null
ZHU Shijie
,
ZHAO Jie
,
WANG Fugang
,
CAO Zhiben Dalian University of Technology
,
Liaoning
,
China. To whom correspondence should be addressed.
材料科学技术（英）
The effects of the eutectic carbides rand secondary carbides on creep deformation and rupture in smooth bars and CT specimens have been studied. The results show that the resistance of the eutectic carbides of skeleton shape to crack growth is larger than that of the blocky shape carbides. The dendritic segregation of secondary carbides promotes the creep ductility. As the secondary carbide particles become coarser, the creep ductility increases and the crack growth rate decreases. However, if the size of secondary carbide is too large, the creep strength decreases too much and therefore crack growth rate increases.
关键词:
creep
,
null
,
null
,
null
