稀土镍铜合金铸铁耐碱腐蚀性能研究

Caustic Corrosion Resistance of RE-Ni-Cu Alloy Cast Iron

采用动态失重法测定稀土镍铜合金铸铁在高温浓碱液中的腐蚀速度,借助光学显微镜和扫描电镜观察显微组织和表面腐蚀形貌,利用能谱仪分析表面微区成分。结果表明:高温浓碱中的动态腐蚀条件下,稀土含量为0.05%的试样耐碱蚀性相对较好,其微观腐蚀表面呈现出平坦、基体面积大和凸起碳化物量少的特点;稀土镍铜合金铸铁的碱腐蚀属于均匀腐蚀,其耐蚀性主要取决于石墨和碳化物的数量、大小和分布;微观基体上富集的镍和铜有利于提高该区域的耐蚀性。

The corrosion rates of RE-Ni-Cu alloy cast irons in hot concentrated alkaline solution were measured by using dynamic condition hydrometer method; the microstructures and surface corrosion morphology of alloy cast irons were observed by means of the optical microscope and SEM; the composition was analyzed using XES. Experimental results showed that the corrosion resistance of the alloy cast iron with 0.05% RE is better, and its etched surface is flat with bigger area of matrix and less quantity of bellied carbide. The caustic corrosion of Re-Ni-Cu alloy cast irons is uniform corrosion, which mainly lies on the quantity, dimension and distribution of the graphite and carbide. The Ni and Cu enriched in the matrix are advantageous to the improvement of caustic corrosion resistances of that zone.