摘要
通过透射电子显微(TEM)微观组织观察、特征电位分析和海洋大气环境暴露试验,研究了7B04铝合金T6热处理状态下的微观组织特征及其对腐蚀行为的影响.结果表明,7B04铝合金经T6峰值时效处理,MgZn_2相沿晶界呈链状析出,同时沿轧制方向具有较强的晶粒变形和取向,为晶间腐蚀的发生提供了条件;自腐蚀电位和点蚀电位较低,在海洋大气环境下耐腐蚀性能差,腐蚀行为表现为点蚀-晶间腐蚀-剥层腐蚀的演变过程,导致力学性能显著下降.
The microstructure of 7B04 aluminum alloy after T6 heat treatment was characterized by transmission electron microscopy （TEM） and its influence on corrosion behavior was studied by means of marine atmospheric exposure test and electrochemical analysis. The results showed that after T6 peak value aging treatment, MgZn2 in the alloy precipitates as chain along grain boundaries, and grains of the alloy were obviously deformed and prefrentialy oriented along the rolling direction, which might be fovour to intergranular corrosion; the open circuit potential （OCP） and pitting potential of the alloy is low; the corrosion resistance is poor in marine atmosphere; the corrosion behavior of the alloy seems to be an evolution process of pitting corrosion-intergranular corrosion-exfoliation corrosion, which leads to significant degradation of mechanical property.
出处
《腐蚀科学与防护技术》
CAS
CSCD
北大核心
2012年第6期458-462,共5页
Corrosion Science and Protection Technology
基金
国防基础科研计划项目(A1020110014)资助
