镍铜合金铸铁耐碱腐蚀机理

Research on the Alkali Corrosion Resistance Mechanism of Ni-Cu Alloy Cast Iron

针对天然碱制碱工业中设备的腐蚀问题,研制出5种成分的镍铜合金铸铁,对其进行了金相组织分析,在此基础上,利用自制的动态腐蚀试验装置模拟碱腐蚀条件,测试其腐蚀速度,并对其耐碱腐蚀性能进行评价。借助扫描电镜对镍铜合金铸铁的表面腐蚀形貌和微区成分分析,详细讨论了镍、铜在铸铁中的作用与耐蚀机理。结果表明,镍铜合金铸铁在高温浓烧碱液中宏观上属于全面腐蚀,微观上存在不同程度的镍、铜元素富集,其中N4、N5合金铸铁耐蚀性较高。

Five types of Ni-Cu cast iron were developed in allusion to facility corrosion problem in caustic alkali industry. The corrosion rate was tested by the dynamic corrosion experiment equipment self-made simulating the alkali corrosion condition on the base of organic analyzing. Ni, Cu action and corrosion resistance mechanism were discussed detailedly through analyzing corrosion shape and components by SEM. The results showed that Ni-Cu cast iron was uniform macroscopically in the dense caustic alkali at high temperature and there was Ni-Cu enrichment microcosmically. Corrosion resistance of N4 and N5 is higher than that of the others.