Cu-7Ni-7Al合金在人工海水中的腐蚀特征  

Corrosion characteristics of Cu-7Ni-7Al alloy in artificial seawater

作　　者：宋正成 贾淑果[1,2] 周延军 宋克兴[1,2] 米绪军 李周[4] SONG Zheng-cheng;JIA Shu-guo;ZHOU Yan-jun;SONG Ke-xing;MI Xu-jun;LI Zhou(Central South University,Changsha 410006,China;Collaborative Innovation Center of Nonferrous Metals,Henan Province,Luoyang 471023,China;Central Research Institute for Nonferrous Metals,Beijing 100088,China;College of Materials Science and Engineering)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471023 [2]有色金属共性技术河南省协同创新中心,河南洛阳471023 [3]北京有色金属研究总院,北京100088 [4]中南大学材料科学与工程学院,湖南长沙410006

出　　处：《材料热处理学报》2019年第2期83-89,共7页Transactions of Materials and Heat Treatment

基　　金：国家重点研发计划(2016YFB0301400);河南省基础与前沿技术研究项目(162300410049)

摘　　要：通过静态全浸试验、扫描电镜(SEM)和电化学测试探讨了Cu-7Ni-7Al合金在人工海水中腐蚀性能。结果表明:在人工海水中,Cu-7Ni-7Al合金的腐蚀速率随浸泡时间的延长而降低,在浸泡144 h前迅速下降,由24 h时的0.0782 g·m^(-2)·h^(-1)降到144 h时的0.0253 g·m^(-2)·h^(-1),在144 h后趋向平稳;合金表面膜的紧密性和厚度逐渐增加,表明合金的耐蚀性能得到改善,但是也存在裂纹和点蚀;电荷转移电阻R_(ct)随着浸泡时间的延长而增加,由3.03×10~4Ω·cm^2增加至9.78×10^(4 )Ω·cm^2;在整个浸泡阶段,自腐蚀电位受表面膜状态影响而波动不明显,电流密度随浸泡时间延长而逐渐降低,在144 h前下降较快,由0 h时的20.13μA/cm^2降到144 h时的6.42μA/cm^2,在144 h后趋向稳定,于240 h达到最小,为5.81μA/cm^2。The corrosion properties of Cu-7 Ni-7 Al alloy in artificial seawater were investigated by static immersion test, scanning electron microscopy(SEM) and electrochemical test. The results show that the corrosion rate of the Cu-7 Ni-7 Al alloy decreases with the increase of immersion time in artificial seawater and decreases rapidly in the first 144 h, from 0.0782 g·m^-2·h^-1after immersion for 24 h to 0.0253 g·m^-2·h^-1 after immersion for 144 h, and tends to be stable after 144 h. The compactness and thickness of the film on the surface of the alloy increase gradually, which indicates that the corrosion resistance of the alloy is improved, but there are also cracks and pitting. With the increase of immersion time, the charge transfer resistance(Rct) of the alloy increases from 3.03×104 Ω·cm^2 to 9.78×104 Ω·cm^2. During the whole immersion stage, the self-corrosion potential fluctuates little attributed to the surface film state, and the current density of the alloy decreases gradually with the increase of immersion time, and decreases more quickly in the first stage, from 20.13 μA/cm^2 after immersion for 0 h to 6.42 μA/cm^2 after immersion for 144 h, and tends to be stable after 144 h, and reaches its minimum after 240 h, which is 5.81 μA/cm^2.

关 键 词：Cu-7Ni-7Al合金 腐蚀速率 极化曲线 交流阻抗 保护膜 

分 类 号：TG146.1[一般工业技术—材料科学与工程]