中文摘要：

采用电弧熔炼和机械合金化并热压制备了晶粒尺寸差别较大的两种Cu-50Cr合金，对比研究了其在酸性介质中的腐蚀机理和耐腐蚀性能及其晶粒尺寸降低后对其腐蚀性能的影响．结果表明：随着H^＋浓度的增加，不同晶粒尺寸Cu-50Cr合金的腐蚀速度加快；晶粒尺寸降低后，其抗腐蚀性能降低；粗品Cu-50Cr合金的腐蚀过程受电化学反应控制；纳米尺寸Cu-50Cr合金的腐蚀过程由电化学反应控制转为扩散控制．

英文摘要：

Cu-5OCr alloys with the different grain size were prepared by conventional casting and hotpressing the mechanically pre-alloyed powder. Then their corrosion behavior in acidic media was investigated by mesearements of potentiodynamic polarization curves and electrochemical impedance spectroscopy （EIS）. With the increment of hydrogen ion concentrations of the media, their corrosion current densities increased and therefore corrosion rates became faster. The corrosion current densities of nanocrystalline Cu-50Cr alloy were higher than those of the corresponding coarse grained material. This showed that the corrosion resistance decreased when the grain size was refined. The corrosion processes of the coarse grained Cu-50Cr alloy are controlled by the electrochemical reactions, while those of the nanocrystalline Cu-50Cr alloy are controlled by the electrochemical reactions initially and afterwards diffusion.