(1. 常州大學(xué) 材料科學(xué)與工程學(xué)院，常州 213164；
2. 北京科技大學(xué) 環(huán)境斷裂教育部重點(diǎn)實(shí)驗(yàn)室，北京 100083)
摘 要: 采用陰極極化、慢應(yīng)變速率拉伸試驗(yàn)(SSRT)和定氫儀研究陰極極化對(duì)7050鋁合金應(yīng)力腐蝕行為的影響。結(jié)果表明：當(dāng)陰極極化電位高于-1100 mV時(shí)，7050鋁合金的應(yīng)力腐蝕敏感性(Iscc)隨著極化電位的負(fù)移而升高；而當(dāng)陰極極化電位低于-1100 mV時(shí)，Iscc則隨著極化電位的負(fù)移而下降。外加極化電位對(duì)不同時(shí)效狀態(tài)7050鋁合金Iscc的影響程度不同，即陰極極化對(duì)欠時(shí)效狀態(tài)下鋁合金的Iscc影響顯著，對(duì)過(guò)時(shí)效狀態(tài)鋁合金Iscc的影響最小，對(duì)峰時(shí)效狀態(tài)下鋁合金Iscc的影響居中。鋁合金的應(yīng)力腐蝕機(jī)理為陽(yáng)極溶解和氫脆共同作用，且氫對(duì)鋁合金應(yīng)力腐蝕的作用隨著氫濃度的增加而增加。
關(guān)鍵字: 7050鋁合金；應(yīng)力腐蝕；氫脆；陰極極化；慢應(yīng)變速率拉伸
（1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. Key Laboratory of Environment Fracture, Ministry of Education,
University of Science and Technology Beijing, Beijing 100083, China）
Abstract:The effects of cathodic polarization on stress corrosion behavior of 7050 aluminum alloy were studied by cathodic polarization, slow strain rate test (SSRT) and hydrogen determinator. The results show that the stress corrosion cracking (SCC) susceptibility (Iscc) of 7050 aluminum alloy increases with shifting negatively the polarization potential when the cathodic polarization potential is higher than -1100 mV, whereas it decreases when the cathodic polarization potential is lower than -1100 mV. The extent for the effect of polarization potential on Iscc is different among the 7050 aluminum alloys with various aging states. Cathodic polarization has greater effect on SCC of under-aged 7050 aluminum alloy than on that of over-aged 7050 aluminum alloy, and the peak aged 7050 aluminum alloy is in the middle. The SCC mechanism of aluminum alloy is a combination of anodic dissolution with hydrogen embrittlement, and the effect of hydrogen on SCC of aluminum alloy increases with increasing the hydrogen concentration.
Key words: 7050 aluminum alloy; stress corrosion; hydrogen embrittlement; cathodic polarization; slow strain rate test
