Effect of hydrogen content on impact property of A357 alloy
This paper investigated the hydrogen content of different artificial moisture atmospheres.The impact property of A357 alloy was performed.The artificial humidity was obtained by using refractory brick with different water content.Then the microenvironment above the melt resulted in different dissolved hydrogen content.The impact specimens was solution treated at 540±3℃ for 12h;water quenched at 60-100℃;and aged at 165±1℃ for 6h.The hydrogen content was measured by HYSCAN II analyzer.The impact test was carried out at Roell450 pendulum impact testing machine.The micro-structure and fracture morphology were observed respectively by Leica DMRE microscope and S-3400N SEM.The specimens have the similar morphology:the obvious dimple feature,and the high tearing ridge,which shows the character of ductile fracture.The hydrogen induced pinholes are took on sub-circular shape and distributed dispersedly.The impact test results showed that the impact energy has strong relation with the hydrogen content.The total absorption energy increases with the increase of hydrogen content.The crack propagation energy Avp and present larger proportion than the initial crack energy AvI in the total absorption energy Av.The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones.The specimen with irregular sub-circular pinholes has larger KI,and more crack propagation resistance.The fracture morphologies appear typical ductile feature,the number of dimples increases,and the dimples change from shallower to deeper.
Hydrogen content A357 Impact energy Pinhole Fracture morphology
Zhengbing Xu Juan He Yongzhi Zou Lijun Wang Jianmin Zeng
State Key Lab.of Solidification Processing,Northwest Polytechnic University,Xian 710072,China Key L State Key Lab.of Solidification Processing,Northwest Polytechnic University,Xian 710072,China Key Lab.of New Processing Technology for Nonferrous Metals and Materials,Guangxi University,Nanning,
国际会议
成都
英文
431-435
2009-10-16（万方平台首次上网日期，不代表论文的发表时间）