预析出对2519A铝合金局部腐蚀性能的影响  

Effect of Pre-precipitation on Localized Corrosion Properties of 2519A Aluminum Alloy

作　　者：刘瑛[1] 张品芳[1] 陈兰君[1] 张合[2] 张新明[3] 耿占吉[3] 

机构地区：[1]南京理工大学材料科学与工程学院,南京210094 [2]南京理工大学机械学院,南京210094 [3]中南大学材料科学与工程学院,长沙410083

出　　处：《材料工程》2014年第6期11-17,共7页Journal of Materials Engineering

基　　金：国家重点基础研究发展计划项目(2005CB623700);国家青年科学基金项目(51304123);教育部科学技术研究重大项目(311035)

摘　　要：研究了固溶后预析出对2519A铝合金的拉伸性能、恒载荷应力腐蚀和晶间腐蚀性能的影响,并通过透射电镜进行组织观察,分析了影响机理。结果表明:预析出提高了T6态2519A合金局部腐蚀性能,合金应力腐蚀开裂时间由无析出时的1天提高至9天,晶间腐蚀最大深度由220μm下降到120μm,而抗拉强度仍有400MPa。合适的预析出也可提高T8态合金局部腐蚀性能,开裂时间由无析出时的10天可增加到520℃析出时的14.9天,晶间腐蚀的最大深度和腐蚀形貌无明显变化,而预析出的抗拉强度有所降低。合适的预析出使T6与T8态样品晶界析出相粗化,间距加大,这是局部腐蚀性能提高的主要原因。The influence of pre-precipitation on tensile mechanical properties,stress corrosion cracking and intergranular corrosion properties of 2519 Aaluminium alloy was studied.The mechanism was analyzed through microstructure observation by transmission electron microscope.The results show that for 2519A-T6 samples,pre-precipitation can improve localized corrosion resistance.Stress corrosion cracking time by constant load test increases from 1day（no pre-precipitation）to 9 days（pre-precipitation）.Maximum intergranular corrosion depth decreases from 220μm to 120μm while ultimate tensile strength still remains 400MPa.Localized corrosion properties of 2519A-T8samples are improved by pre-precipitation.Cracking time prolongs from 10 days（no pre-precipitation）to 14.9 days（preprecipitation）.Maximum intergranular corrosion depth and its corrosion morphology remain unchanged while ultimate tensile strength of pre-precipitation T8-samples is decreased.Proper pre-precipitation can enhance the discontinuity and coarsening of precipitates in grain boundary for both T6 and T8 temper,in which is due to enhancement of localized corrosion resistance.

关 键 词：2519A铝合金 预析出 晶间腐蚀 应力腐蚀开裂 

分 类 号：TG146[一般工业技术—材料科学与工程]