3.0%NaCl溶液中局部腐蚀的影响
(1.浙江大学 化学系， 杭州 310027；
2.中国科学院 金属研究所 腐蚀与防护国家重点实验室，
沈阳 110016)
摘 要: 研究了T8态峰时效及T6态峰时效Al-4.0Cu-1.0Li-0.4Mg-0.4Ag-0.14Zr合金在3.0% NaCl溶液中的局部腐蚀行为及其电化学阻抗特征。结果表明：T8态峰时效处理时合金的电荷转移反应电阻大于T6态峰时效时的相应值；合金腐蚀初期，主要发生沿Cu或Fe含量较高的第二相粒子边缘的孔蚀，后期由于亚晶界边缘贫Cu无沉淀带的阳极溶解而出现连续亚晶界腐蚀；时效前的预变形减少了贫Cu无沉淀带的宽度，可降低亚晶界腐蚀程度。
关键字: Al-Li合金；NaCl溶液；局部腐蚀；时效；预变形
Al-4.0Cu-1.0Li-0.4Mg-0.4Ag-0.14Zr alloy in 3.0% NaCl solution
（1. Department of Chemistry, Zhejiang University,
Hangzhou 310027, China;
2. State Key Laboratory for Corrosion and Protection, Institute of Metals Research,
The Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:The localized corrosion behavior and electrochemical impedance spectrum characteristics of T8 peak-aged and T6 peak-aged Al-4.0Cu-1.0Li-0.4Mg-0.4Ag-0.14Zr alloys immersed in 3.0% NaCl solution were studied. The results show that the charge-transfer reaction resistance of T8 peak-aged alloy is greater than that of T6 peak-aged one. During the early immersion, pitting corrosion, the major corrosion form, occurs at the edge of more Cu/Fe-containing constituent particle. With increasing immersion time, subgrain boundary corrosion is formed due to anodic dissolution of Cu-depleted precipitates-free zone. Pre-deformation before aging deters the formation of Cu-depleted precipitates-free zone and decreases the subgrain boundary corrosion.
Key words: Al-Li alloy; localized corrosion; NaCl solution; aging; pre-deformation
