DONG Jianxin XIE Wei~* XU Zhichao XIE Xishan ZHANG Shouhua University of Science and Technology Beijing
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Beijing
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China doctorate student P.O.Box 604
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University of Science and Technology Beijing
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Beijing 100083
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China
金属学报(英文版)
Micro-alloying of Mg,ranged from 30 to 70 ppm,may improve the high temperature ductility,stress rupture,especially,certain important mechanical properties,such as cyclic stress rupture,creep/fatigue interaction and crack propagation rate.The quantity, morphology and distribution of δ-phase may obviously influence the notched cyclic stress rup- ture life.The relevant microstructure shows that the Mg may also influence to certain extent on the feature of δ-phase.Thus,to keep the Mg and δ-phase under control may further im- prove the mechanical properties of alloy GH169.
关键词:
superalloy GH169
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QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
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Beijing
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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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