AZ31+xLa镁合金在3.5%NaCl溶液中的腐蚀机理研究  

Corrosion Mechanism of Magnesium Alloys AZ31+xLa in 3.5% NaCl Solution

作　　者：王嵬[1] 魏大卫[1] 刘艇安 于祺[3] 付振波[1] 朱龙迪 张万友[1] 

机构地区：[1]东北电力大学化学工程学院,吉林132012 [2]辽宁东科电力有限公司,沈阳110006 [3]华北电力大学科技学院,保定071000

出　　处：《腐蚀科学与防护技术》2017年第4期375-380,共6页Corrosion Science and Protection Technology

基　　金：吉林省科技厅科技发展计划项目(20140520100JH和20140204043GX);吉林省科技局指导性科技计划(201467008)~~

摘　　要：通过腐蚀失重、电化学测试、扫描电镜(SEM)、能谱分析(EDS)、X射线衍射(XRD)和金相显微镜(OM)等实验手段,研究了AZ31+x La镁合金在3.5%(质量分数)NaCl溶液中的腐蚀机理。结果表明:随La含量的增加,合金腐蚀速率先增大后减小,腐蚀电位负移,腐蚀电流密度先升高后降低,新相Al_(11)La_3的析出使β相更细小且分布更加均匀。其中AZ31+1.1La的晶粒尺寸最小,自腐蚀速率和腐蚀电流密度最小,耐蚀性最强。168 h的自腐蚀速率较AZ31下降28.59%,腐蚀电流密度为1.03×10^(-6)A/cm^2,较AZ31降低了一个数量级。The corrosion mechanism of Mg-alloys AZ31 ＋ xLa in 3.5%（mass fraction） NaCl solution was studied by means of the corrosion weight loss test, electrochemical measurement, SEM, EDS, XRD and OM. For the Mg-alloys AZ31＋x La, it was found that the corrosion rate and corrosion current density increased at first then decreased, corrosion potential moved negatively when the La content increased.The precipitated Al_（11）La_3 phase caused the β phase becoming finer, thereby, which distributed much uniformly. Among others, the Mg-alloy AZ31＋1.1La possessed the minimum value in grain size, corrosion rate and corrosion current density, namely the best corrosion resistance. The corrosion rate of AZ31 ＋1.1La was reduced by 28.59% in comparison with AZ31 in the mass loss test for 168 h. The corrosion current density of AZ31 ＋ 1.1La was 1.03 × 10^（-6）A/cm^2, which has decreased one order of magnitude compared with AZ31.

关 键 词：AZ31+xLa镁合金 腐蚀机理 Al11La3析出相 

分 类 号：TG172[金属学及工艺—金属表面处理]