Yang Miao, Liu Xiaobo, Xing Liyun, Chen Zhaoyu
Engineering Training Center, Beihua University, Jilin 132021, China.
College of Mechanical Engineering, Beihua University, Jilin 132021, China.
Materials (Basel). 2023 Mar 17;16(6):2406. doi: 10.3390/ma16062406.
Hydrogen embrittlement and the anodic dissolution mechanism are two important aspects of the corrosion behavior of magnesium alloys. Here, to evaluate the effects of these two aspects on the corrosion failure of magnesium alloys under stress, the stress and corrosion behaviors of the AM50 magnesium alloy in air, deionized water, and NaCl solution after solid-solution (T4) treatment were investigated by X-ray diffraction, scanning electron microscopy, slow strain rate tensile testing, and vacuum dehydrogenation. The as-cast AM50 magnesium alloy was mainly composed of the α-Mg and β-MgAl phases. After T4 treatment, the amount of the β-MgAl phase was significantly reduced, and only a small amount existed at the grain boundaries. After T4 treatment, the stress corrosion resistance in deionized water improved, but it decreased in an NaCl environment. Dehydrogenation experiments showed that the effect of hydrogen on the corrosion process was weakened owing to the decrease of the β-MgAl phase after solution treatment. The effects of hydrogen embrittlement and the anodic dissolution mechanism on the corrosion behavior of the AM50 magnesium alloy under stress were different. In deionized water, the hydrogen embrittlement mechanism played the major role, while the anodic dissolution mechanism played the major role in the presence of Cl ions.
氢脆和阳极溶解机制是镁合金腐蚀行为的两个重要方面。在此，为评估这两个方面对应力作用下镁合金腐蚀失效的影响，通过X射线衍射、扫描电子显微镜、慢应变速率拉伸试验和真空脱氢等方法，研究了固溶（T4）处理后的AM50镁合金在空气、去离子水和NaCl溶液中的应力及腐蚀行为。铸态AM50镁合金主要由α-Mg和β-MgAl相组成。T4处理后，β-MgAl相的数量显著减少，仅在晶界处存在少量。T4处理后，在去离子水中的抗应力腐蚀性能提高，但在NaCl环境中降低。脱氢实验表明，固溶处理后由于β-MgAl相减少，氢对腐蚀过程的影响减弱。氢脆和阳极溶解机制对应力作用下AM50镁合金腐蚀行为的影响不同。在去离子水中，氢脆机制起主要作用，而在存在Cl离子的情况下，阳极溶解机制起主要作用。
