3.0%NaCl溶液中局部腐蝕的影響
曹發(fā)和1，張鑒清1,2，曹楚南1，2
(1.浙江大學(xué) 化學(xué)系， 杭州 310027；
2.中國(guó)科學(xué)院 金屬研究所 腐蝕與防護(hù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，
沈陽(yáng) 110016)
摘 要: 研究了T8態(tài)峰時(shí)效及T6態(tài)峰時(shí)效Al-4.0Cu-1.0Li-0.4Mg-0.4Ag-0.14Zr合金在3.0% NaCl溶液中的局部腐蝕行為及其電化學(xué)阻抗特征。結(jié)果表明：T8態(tài)峰時(shí)效處理時(shí)合金的電荷轉(zhuǎn)移反應(yīng)電阻大于T6態(tài)峰時(shí)效時(shí)的相應(yīng)值；合金腐蝕初期，主要發(fā)生沿Cu或Fe含量較高的第二相粒子邊緣的孔蝕，后期由于亞晶界邊緣貧Cu無沉淀帶的陽(yáng)極溶解而出現(xiàn)連續(xù)亞晶界腐蝕；時(shí)效前的預(yù)變形減少了貧Cu無沉淀帶的寬度，可降低亞晶界腐蝕程度。
關(guān)鍵字: Al-Li合金；NaCl溶液；局部腐蝕；時(shí)效；預(yù)變形
Al-4.0Cu-1.0Li-0.4Mg-0.4Ag-0.14Zr alloy in 3.0% NaCl solution
CAO Fa-he1， ZHANG Jian-qing1, 2, CAO Chu-nan1, 2
（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
