(1. 中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083；
2. 中南大學(xué) 化學(xué)化工學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用循環(huán)極化、U型樣法、慢應(yīng)變速率拉升、金相表征等手段對(duì)比研究熱處理制度對(duì)7150鋁合金電化學(xué)腐蝕性能和應(yīng)力腐蝕性能的影響；并從TEM晶界析出相分布、晶界腐蝕形貌、點(diǎn)蝕發(fā)生發(fā)展機(jī)理以及應(yīng)力腐蝕開裂機(jī)制等角度，對(duì)電化學(xué)參數(shù)與應(yīng)力腐蝕敏感性之間的一致性關(guān)系進(jìn)行理論說(shuō)明。結(jié)果表明:第二點(diǎn)蝕電位(φpit,2)及其相應(yīng)電位差值(φpit,2-φcorr、φpit,2-φrep)隨時(shí)效的變化趨勢(shì)與耐應(yīng)力腐蝕能力隨時(shí)效的變化趨勢(shì)完全一致。
關(guān)鍵字: 7150鋁合金；第二點(diǎn)蝕電位；電位差；應(yīng)力腐蝕敏感性；熱處理
（1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract: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.
Key words: 7150 Al alloy; second pitting potential; potential difference; stress cracking corrosion susceptibility; heat treatment
