高温预析出对Al-5.8Zn-2.7Mg-1.6Cu铝合金应力腐蚀的影响  

Effect of High Temperature Pre-precipitation on Stress Corrosion of Al-5.8Zn-2.7Mg-1.6Cu Aluminum Alloy

作　　者：李安敏[1,2] 徐飞 黄宇炜[1,2] 孔德明 LI Anmin;XU Fei;HUANG Yuwei;KONG Deming(Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials,Guangxi University,Nanning Guangxi 530004,China;School of Resources,Environment and Materials,Guangxi University,Nanning Guangxi 530004,China)

机构地区：[1]广西大学广西有色金属及特色材料加工重点实验室,广西南宁530004 [2]广西大学资源环境与材料学院,广西南宁530004

出　　处：《上海金属》2019年第3期49-55,共7页Shanghai Metals

基　　金：2017年第一批广西创新驱动发展专项(科技重大专项)(No.桂科AA17202008);广西大学广西有色金属及特色材料加工重点试验室开放基金(No.15-140-03)

摘　　要：对Al-Zn-Mg-Cu铝合金进行固溶(预析出)处理、室温水淬及人工时效。通过室温力学性能测试、慢应变速率拉伸试验、硬度测试、电导率测量及应力腐蚀试验,结合光学显微镜、扫描电镜和能谱分析,研究了高温预析出对Al-5.8Zn-2.7Mg-1.6Cu铝合金的组织和应力腐蚀的影响。结果表明:高温预析出可以改变合金晶内和晶界的析出相大小和分布,能抑制阳极溶解和氢脆,从而提高合金的力学性能和抗应力腐蚀性能。经420℃预析出处理的合金的应力腐蚀敏感性最低,抗应力腐蚀性能增强,但强度和硬度有所降低。Al-5.8Zn-2.7Mg-1.6Cu铝合金获得较佳抗应力腐蚀性能的高温预析出工艺为470℃×1h+420℃×0.5h。Al-Zn-Mg-Cu aluminum alloy was solution treated(pre-precipitation treatment),water quenched and artificial aged.The effects of high temperature pre-precipitation treatment on microstructures and stress corrosion of Al-5.8Zn-2.7Mg-1.6Cu aluminum alloy were investigated by mechanical test at room temperature,slow strain rate test(SSRT),hardness measurement,electrical conductivity and stress corrosion test in conjuction with optical microscopy and scanning electronic microscopy and EDS.The results showed that high temperature pre-precipitation could change the size and distribution of precipitates in grain interior and grain boundary of the alloy,and inhibit the dissolution of the anode and the hydrogen embrittlement,thus improving mechanical properties and resistance to stress corrosion cracking(SCC)of the alloy.The susceptibility to SCC of the alloy subjected to pre-precipitating at 420℃was the lowest,its resistance to SCC increased,but its strength and hardness decreased.The high temperature pre-precipitation process by which the Al-5.8Zn-2.7Mg-1.6Cu aluminum alloy can obtain better resistance to SCC was solution treatment at 470℃for 1 h and then pre-precipitation treatment at 420℃for 0.5 h.

关 键 词：Al-5.8Zn-2.7Mg-1.6Cu铝合金 高温预析出 应力腐蚀 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG166.3[金属学及工艺—金属材料] V252.2[金属学及工艺—金属学]