YANG Wangyue ZHA NG Jishan CHEN Guoliang Beijing University of Science and Technology
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Beijing
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ChinaTIAN Shusen GENG Qingquan Fushun Steel Works
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Fushun
,
Liaoning
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China
金属学报(英文版)
The fatigue-creep interaction behaviour of superalloy GH698 with different grain sizes has been studied at 700℃.The results show that three zones,F,C and FC,can be distinguished at the fatigue-creep interaction curves.In zones FC and C,the presence of alternative stresses inhibits the creep deformation process therefore delays the fracture of the alloy.This effect will be enhanced by grain refining.However,in zone F,grain refining exhibits an inverse ef fect under large alternative stresses.
关键词:
Ni-base alloy
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QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
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Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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