NaCl沉积和SO_2污染对镁合金初期大气腐蚀行为的影响  

Atmospheric Corrosion Initial Stages of Magnesium Alloy in the Presence of NaCl and SO_2

作　　者：林翠[1] 李晓刚[1] 

机构地区：[1]北京科技大学材料科学与工程学院腐蚀与防护中心,北京100083

出　　处：《北京科技大学学报》2004年第5期524-528,共5页Journal of University of Science and Technology Beijing

基　　金：科技部国家基础条件平台重点项目(No.2003data2C018);国家"973"项目"材料环境行为与失效机理"(No.19990650)

摘　　要：借助扫描电镜(SEM/EDX)、X射线衍射(XRD)研究了NaCl单个因素对镁合金AZ91D初期腐蚀行为的影响,并对SO2和NaCl的协同作用进行了探讨.NaCl存在时初期破坏金属表面的保护膜,但后期微溶性腐蚀产物的生成导致腐蚀速率的降低.当NaCl和SO2同时存在时,反应生成的可溶性产物不具有阻碍的作用,同时他们会发生部分溶解生成自由移动的离子,大量难溶物在镁合金表面难以短时间形成,故NaCl和SO2同时存在引起的腐蚀远大于两者单独存在时引起的腐蚀加和.NaCl和SO2对镁合金的初期大气腐蚀具有明显的协同作用.The effects of NaCl and SO2 on the initial atmospheric corrosion of AZ91D magnesium alloy were studied with a simulated atmospheric corrosion system. The analyses of surface morphology, corrosion products and rust layer structure were integrated by Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) to investigate the corrosion performance. The results showed that NaCl accelerated the initial atmospheric corrosion of the alloy. The protective film was destroyed in the initial period, but the corrosion rate slowed down because of the formation of slight soluble corrosion products in the later periods in the presence of NaCl. Soluble corrosion products with no inhibitive function developed and partly solved to form the ions of free motion when NaCl and SO2 existed simultaneously. A great deal of these products were very difficult to grow on the surface in a short time. The combined effect of NaCl and SO2 on the initial atmospheric corrosion was greater than that caused by each single component.

关 键 词：SO2 NACL 初期 AZ91镁合金 协同作用 

分 类 号：TG172.3[金属学及工艺—金属表面处理]