(1.沈阳工业大学 材料科学与工程学院，沈阳 110178；2. 辽阳技师学院 机械系，辽阳 111000)
摘 要: 采用热喷焊工艺在20号钢基体上制备F102及含0.5%Ce的F102镍基自熔合金涂层，通过组织分析和性能测试，研究Ce对F102合金的变质作用及机理。 结果表明：两种合金涂层均由γ-Ni、Ni3B、CrB、Ni3Si、(Cr, Fe)23C6和(Cr, Fe)7C3相组成，在连续γ-Ni基体上弥散分布棒状CrB、粒状(Cr, Fe)7C3、小球状Ni3Si及枝状混合共晶化合物，但Ce使组织明显细化。该合金与20号钢相比，其硬度和耐磨性分别提高3.8倍和3.2倍；与F102合金相比，其硬度和耐磨性分别提高14.8%和18%，同时该合金的耐蚀性明显增强。其原因是Ce富集于液固界面，降低Fe-Cr-C共晶转变温度，细化合金显微组织。合金中的Ce参与Fe-Cr-C系统反应，是改变共晶转变温度的主要原因。
关键字: 镍基自熔合金；稀土；涂层；共晶温度；微合金化
（1. School of Materials Science and Engineering, Shenyang University of Technology, Shenyang 110178, China;
2. Department of Mechanical Engineering, Liaoyang Technician College, Liaoyang 111000, China）
Abstract:The coatings of F102 and F102 Ni-based self-fluxing alloy with 0.5%Ce were made on 20# steel by fire spray welding. The metamorphism and mechanism of Ce on F102 alloy were studied based on the microstructure analysis and properties testing. The results show that two kinds of alloy coatings consist of γ-Ni, Ni3B, CrB, Ni3Si, (Cr, Fe)23C6 and (Cr, Fe)7C3, the columnar CrB, granular (Cr, Fe)7C3, small spherical Ni3Si and some dendritic eutectic mixtures are well distributed in the γ-Ni matrix, but the grains in the alloy after adding Ce are much finer than before. The average hardness and wearing resistance of the alloy coating increase by 3.8 and 3.2 times, respectively, compared with those of 20# steel, and also increase by 14.8% and 18%, respectively, compared with those of F102 alloy. Moreover, the corrosion resistance performance of the alloy is increased significantly. The reason is that the element Ce enriched in the liquid-solid interface decreases the eutectic transforming temperature, thus the microtructure of the alloy are refined. The element Ce existing in the alloy participates in the reaction of Fe-Cr-C system, which is the main reason why the eutectic transforming temperature is changed.
Key words: Ni-based self-fluxing alloy; rare earths; coating; eutectic temperature; micro alloying
