镁合金AZ31B在不同pH值NaCl溶液中的应力腐蚀行为研究  

Stress Corrosion Cracking Behavior of AZ31B Magnesium Alloy in NaCl Solution with Different pH Values

作　　者：朱立文[1] 贺秀丽[1] 卫英慧[1,2] 侯利锋[1] 郭春丽[1] 

机构地区：[1]太原理工大学,山西太原030024 [2]吕梁学院,山西吕梁033000

出　　处：《稀有金属材料与工程》2015年第10期2481-2485,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51374151;51001079;21201129);高等学校博士点专项科研基金(20091402110010);教育部中国博士后科学基金(20100471586);山西省自然科学基金(2011011020-2;2010021023-1;2013011012-3)

摘　　要：通过慢拉伸应力腐蚀试验机、电化学工作站和扫描电子显微镜(SEM)等手段,研究挤压态镁合金AZ31B在pH=2、7和12的NaCl溶液中的应力腐蚀行为。结果表明,随pH值增大,AZ31B静态腐蚀速率和应力腐蚀敏感性均降低,这是由于碱性溶液更有利于Mg(OH)2表面保护膜的形成。应力腐蚀试验中点蚀形成主要裂纹源,拉伸断口分析表明应力腐蚀具有多裂纹源特征,应力加速腐蚀进程,断裂方式属于穿晶解理断裂。The stress corrosion behavior of the extruded magnesium alloy AZ31 B in NaCl solutions with different pH values ranging from 2 to 12 was investigated by slow strain rate tensile（SSRT）, electrochemical workstation and SEM. The results indicate that the SCC susceptibility and static corrosion rate have all declined, because it is easy to form a protective film of Mg（OH）2 in alkaline solution. The main crack source is caused by chloride ion pitting corrosion. The tensile fracture of multiple gap shows that the stress corrosion is characterized by many crack sources, and the tensile stress accelerates the corrosion rate. The fracture of slow strain rate tension is transgranular cleavage fracture.

关 键 词：挤压镁合金 PH NACL 应力腐蚀 

分 类 号：TG172.9[金属学及工艺—金属表面处理]