低温长时间加热对T4态6000系铝合金晶间腐蚀性能的影响  

Effect of low-temperature and long-time heating on intergranular corrosion properties of 6000 aluminum alloy after T4 treatment

作　　者：何琼[1] 许晓嫦[1] 任鹏禾 禹灿 何浩鹏[1] HE Qiong XU Xiao-chang REN Peng-he YU Can HE Hao-peng(School of Materials Science and Engineering, Central South University, Changsha 410083, China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2017年第7期107-113,共7页Transactions of Materials and Heat Treatment

基　　金：国家重点基础研究发展规划("973"计划)项目(2012CB619506)

摘　　要：采用晶间腐蚀浸泡实验,研究了低温长时间加热的温度和时间对T4态6000系铝合金晶间腐蚀敏感性的影响,并通过透射电镜观察其基体和晶界析出相的特征,以研究其晶间腐蚀机理。结果表明:低温长时间加热时间一定时,随着加热温度的升高,铝合金的晶间腐蚀敏感性逐渐降低并有轻微点蚀;加热温度一定时,随着加热时间的延长,铝合金的腐蚀类型由晶间腐蚀转变为点蚀。195℃加热450 h后,铝合金析出相特征为基体弥散分布大量的β″相和Q'相,而晶界析出相呈现球状、断续分布且无沉淀析出带(PFZ)较宽,此时,合金的晶间腐蚀敏感性最低。The effect of heated at low-temperature for long time on intergranular corrosion susceptibility of 6000 series aluminum alloy after T4 treatment was studied by intergranular corrosion immersion test. The characteristics of precipitates and the intergranular corrosion mechanism of the alloy were studied by means of transmission electron microscopy observation. The results show that when the heating temperature is low for a long time, with the increasing of heating temperature, the intergranular corrosion susceptibility of the aluminum alloy decreases gradually and the pitting corrosion is slight. When the heating temperature is constant, with the increasing of holding time, the corrosion type of the aluminum alloy is changed from intergranular corrosion to pitting corrosion. After heating at 195℃ for 450 h, the precipitated phase of the aluminum alloy is characterized by a large number of β″ phase and Q＇ phase dispersed in the matrix, while the grain boundary precipitates are spherical, discontinuous distribution and the precipitation free zone（PFZ） is wider, and the intergranular corrosion sensitivity of the alloy is the lowest.

关 键 词：6000系铝合金 热处理 微观组织 晶间腐蚀 

分 类 号：TG146.2[一般工业技术—材料科学与工程]