稀土对低镍铬合金铸铁耐烧碱腐蚀性能的影响

Effect of Rare Earth on the Corrosion Resistance of Nickel Chromium Alloy Cast Iron

采用电化学和动态失重法测定稀土低镍铬铸铁在高温烧碱中的阳极极化曲线和腐蚀速度 ,借助显微镜和扫描电镜观察显微组织和腐蚀形貌 ,结果表明 ,加入稀土可细化低镍铬铸铁组织并改变石墨形态 ,提高耐高温烧碱腐蚀性能。其中DNJ3(0 0 4 6 %RE)腐蚀速度最小 ,维钝电流低 ,钝化区间长 ,是一种优良的耐碱蚀材料。

The corrosion rate and anode polarization curves of Ni Cr cast iron in high temperature caustic soda solution had been determined with the aid of weigh less measurement and electrochemical methods.Microstructure and corrosion surface shape had been examined by means of OM and SEM.The results showed that microstructure of Ni Cr cast iron was fined and the corrosion resistance of it was enhanced by the addition of proper content of rare earth.The best of them was DNJ3(0 046%RE)becaue it′s corrosion speed was minimum and it′s passivity properties was better satisfactory.