Influence of ammonium sulfate on the corrosion behavior of AZ31 magnesium alloy in chloride environment  

作　　者：Feng Ge Zhongyu Cui Yue Liu Li Lei Xin Wang Hongzhi Cui 

机构地区：[1]School of Materials Science and Engineering,Ocean University of China,Qingdao 266100,China [2]Beijing National Innovation Institute of Lightweight Ltd.Beijing,101499,China

出　　处：《Journal of Magnesium and Alloys》2024年第3期1082-1101,共20页镁合金学报（英文）

基　　金：support of National Natural Science Foundation of China(No.U2106216);the National Science and Technology Resources Investigation Program of China(No.2019FY101400);the Youth Innovation Plan of Shandong Province(2019KJD001).

摘　　要：Electrochemical corrosion of AZ31 magnesium alloy in the NH_(4)^(+)-SO_(4)2−-Cl−environment is studied.Effect of NH_(4)^(+)overshadows that of Cl−as the(NH_(4))_(2)SO_(4) concentration is 0.005 M or higher,yielding an evolution from localized corrosion to uniform corrosion.Acceleration effect of NH_(4)^(+)can be attributed to that(i)NH_(4)^(+)dissolves the inner MgO and hinders the precipitation of Mg(OH)_(2) and(ii)the buffering ability of NH_(4)^(+)provides H+,enhances the hydrogen evolution,and expedites the corrosion process.The latter is demonstrated as the dominant factor with the results in unbuffered and buffered environments.The severe corrosion and hydrogen process in NH_(4)^(+)-containing solution results in a high Hads coverage and yields an inductive loop within the low frequency.Meanwhile,SO_(4)^(2−)is helpful in generating cracked but partially protective corrosion products,while Cl−could broaden the corrosion area beneath the corrosion product.

关 键 词：Magnesium alloy Ammonium corrosion Electrochemical kinetic parameter Anodic dissolution. 

分 类 号：TG178[金属学及工艺—金属表面处理]