不同热处理7150铝合金的点蚀电位与应力腐蚀敏感性  

Link between pitting potentials and stress cracking corrosion susceptibility of 7150 Al alloy with different ageing processes

作　　者：孙擎擎[1,2] 陈启元[2] 陈康华[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083 [2]中南大学化学化工学院,长沙410083

出　　处：《中国有色金属学报》2016年第7期1400-1407,共8页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2012CB619502;2010CB731701);国家自然科学基金重点资助项目(51134007);国家自然科学基金资助项目(51201186);湖南省自然科学基金资助项目(12JJ6040);国家重大科研仪器设备研制专项(51327902)~~

摘　　要：采用循环极化、U型样法、慢应变速率拉升、金相表征等手段对比研究热处理制度对7150铝合金电化学腐蚀性能和应力腐蚀性能的影响;并从TEM晶界析出相分布、晶界腐蚀形貌、点蚀发生发展机理以及应力腐蚀开裂机制等角度,对电化学参数与应力腐蚀敏感性之间的一致性关系进行理论说明。结果表明:第二点蚀电位(φ_(pit,2))及其相应电位差值(φ_(pit,2)-φ_(corr)、φ_(pit,2)-φ_(rep))随时效的变化趋势与耐应力腐蚀能力随时效的变化趋势完全一致。The influences of ageing processes on cyclic polarization and stress cracking corrosion（SCC） susceptibility were compared and investigated using cyclic polarization, U-type specimen method, slow strain rate tension and optical microscopy. Fundamental theoretical analysis behind the link pitting potentials and SCC susceptibility of 7150 Al alloys with different ageing processes was analyzed theoretically, based on grain boundary precipitates distribution revealed by TEM, corrosion morphology of grain boundary, initiation and propagation mechanisms of pitting corrosion and SCC mechanism. The results show that the trend of electrochemical parameters（the second pitting potential φpit,2 and potential differences, such as（φpit,2-φcorr） and（φpit,2-φrep） as function of ageing process is same exactly with the trend of SCC resistance as function of ageing process.

关 键 词：7150铝合金 第二点蚀电位 电位差 应力腐蚀敏感性 热处理 

分 类 号：O646.6[理学—物理化学]