Stress corrosion cracking behaviors of RE-containing ME21 magnesium alloy processed by equal-channel angular pressing
来源期刊：JOURNAL OF RARE EARTHS2019年第1期
论文作者：Jinghua Jiang Qiuyuan Xie Mingshan Qiang Aibin Ma Evans-Kwesi Taylor Yuhua Li Dan Song Jianqing Chen
文章页码：88 - 94
摘 要：A commercial as-cast ME21 magnesium alloy containing rare-earth （RE） element was processed by equalchannel angular pressing to obtain fine-grained micro structure. Stress corrosion cracking （SCC） behaviors of the fine-grained samples were studied by slow-strain-rate testing in air, distilled water and Hanks’solution at the strain rate of 1×10-6 s-1. All samples show a relatively low SCC sensitivity in distilled water but a great SCC tendency in Hanks’ solution. The microscopic observations of the fracture surfaces and the side surfaces reveal obvious active anodic dissolution and hydrogen embrittlement cracks, which indicate the higher SCC susceptibility in Hanks’solution. The fine-grained microstructure with more crystal defects promotes the passivation process of the oxide film and restrains the hydrogen induced cracking of the ME21 magnesium alloy, leading to the higher general corrosion resistance as well as SCC resistance.
Jinghua Jiang1，Qiuyuan Xie1，Mingshan Qiang1，Aibin Ma1,2，Evans-Kwesi Taylor1，Yuhua Li1,2，Dan Song1,2，Jianqing Chen1
1. College of Mechanics and Materials, Hohai University2. Suqian Institute, Hohai University
摘 要：A commercial as-cast ME21 magnesium alloy containing rare-earth （RE） element was processed by equalchannel angular pressing to obtain fine-grained micro structure. Stress corrosion cracking （SCC） behaviors of the fine-grained samples were studied by slow-strain-rate testing in air, distilled water and Hanks’solution at the strain rate of 1×10-6 s-1. All samples show a relatively low SCC sensitivity in distilled water but a great SCC tendency in Hanks’ solution. The microscopic observations of the fracture surfaces and the side surfaces reveal obvious active anodic dissolution and hydrogen embrittlement cracks, which indicate the higher SCC susceptibility in Hanks’solution. The fine-grained microstructure with more crystal defects promotes the passivation process of the oxide film and restrains the hydrogen induced cracking of the ME21 magnesium alloy, leading to the higher general corrosion resistance as well as SCC resistance.
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