pH值对Cu-17Ni-3Al-X耐磨铸造铜合金腐蚀的影响  

Influence of pH Value on Corrosion of Wear-Resistant Casting Alloy Cu-17Ni-3Al-X

作　　者：罗宗强[1] 辛保亮[1] 张卫文[1] 李元元[1] 

机构地区：[1]华南理工大学机械与汽车工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2011年第11期125-131,共7页Journal of South China University of Technology(Natural Science Edition)

基　　金：教育部新世纪人才支持计划资助项目(NCET-07-0310);广东省经信委技术创新项目(2010108116)

摘　　要：通过静态浸泡腐蚀实验和电化学实验,采用扫描电镜、X射线衍射仪、光电子能谱仪研究了一种Cu-17Ni-3Al-X耐磨铸造铜合金在pH值变化的3.5%(质量分数)NaCl溶液中的耐腐蚀性能和腐蚀行为.结果表明:在3.5%NaCl溶液中,随着溶液pH值的升高,合金腐蚀速率逐渐降低;在中性和碱性溶液中,合金具有优异的耐腐蚀性能;当溶液为强酸性(pH=3)时,合金表面不易形成致密的保护膜;当溶液pH值为6、8、10时,合金表面产生富镍、铝的Cu2(OH)3Cl和Cu2O腐蚀产物膜;在强碱性(pH=12)溶液中,合金容易形成致密的Cu2O膜.合金在不同pH值溶液中的腐蚀速率差异主要是合金电化学反应过程中的阴极反应以及合金表面腐蚀膜的不同引起的;在酸性溶液中,合金在第二相附近出现了晶间腐蚀.The influence of pH value on the corrosion resistance and the corrosion behavior of wear-resistant casting alloy Cu-17Ni-3Al-X in 3.5%（mass fraction） NaCl solution was investigated via static immersion test,electrochemical test,SEM,XRD and XPS.The results show that,in 3% NaCl solution,the corrosion rate of the alloy decreases with the increase of pH value,that the alloy is of excellent corrosion resistance in neutral and alkaline NaCl solution,that no compact protection film forms on the alloy surface when the pH value is 3,that Ni-rich and Al-rich Cu2（OH）3Cl and Cu2O films form on the alloy surface when the pH value is 6,8 and 10,and that compact Cu2O film is easy to form when the pH value is 12.In conclusion,the difference in corrosion rate of the alloy in NaCl solution with different pH values is due to the difference in cathodic reaction and the protection films,and the alloy suffers from intergranular corrosion around the second phases in acid solution.

关 键 词：PH值 铜镍合金 腐蚀速率 耐腐蚀性能 腐蚀行为 

分 类 号：TG172.42[金属学及工艺—金属表面处理]