核电冷凝器用含稀土Cu-30Ni-xRE(x=0~0.213)合金耐腐蚀性能及其机理研究

Research on mechanism of corrosion resistance for Cu-30Ni-xRE(x=0~0.213) alloy

摘要:

核电用冷凝器的失效形式以腐蚀为主，本文利用电化学测试系统、XRD、OM、SEM和EDS等分析测试方法研究Cu-30Ni-xRE(x=0~0.213)合金耐腐蚀性能及其机理，结果表明，与不含稀土的Cu-30Ni合金相比，适量稀土添加的Cu-30Ni-0.095RE合金的Ni元素偏析降低，枝晶和晶间腐蚀驱动力减小，导致腐蚀电位提高约11.0%，腐蚀电流密度iC降低约37.3%。

Abstract:

The mechanism of corrosion resistance for Cu-30Ni-xRE(x=0~0.213) alloy were investigated by employing electrochemical testing, x-ray diffraction, optical microscopy, scanning electrical microscopy and Energy Disperse Spectroscopy. The results showed that comparison with Cu-30Ni alloy without RE, Cu-30Ni-0.095RE alloy with right amount had decreasing composition segregation of Ni element. This resulted in the decease of corrosion driving force between centre of dendrite and interdendritic. As a result, for Cu-30Ni-0.095RE alloy the corrosion potential increased by 11.0%, and the corrosion current decreased by 37.3%.