等离子熔覆高铬铁基涂层磨粒磨损性能与机理

Grain-Abrasion Performance and Mechanism of High-chromium Iron-Base Coating Prepared by Plasma Cladding

采用等离子熔覆技术,在Q235钢表面获得等离子熔覆高铬铁基复合涂层,利用OM、SEM、XRD、EDS分析了涂层的组织结构和相组成,用磨粒磨损试验机对其进行磨粒磨损试验。结果表明:整个涂层内部组织细小、致密、均匀、无气孔、无裂纹;涂层比淬火45#钢耐磨性提高了2.56倍。等离子熔覆涂层磨粒磨损机制主要存在2种类型:塑性变形-切削和断裂-剥落,磨损过程为2种机制的综合作用,涂层组织对磨粒磨损机制有重要影响。涂层具有较高耐磨性的原因主要是固溶体的基体上分布有块状合金碳化物,具有较好的耐磨性。

High-chromium iron-base composite coating was prepared on the surface of Q235 iron by plasma surface met- allurgy. Microstructure and phase composition of the coating were analyzed by OM, SEM,XRD, EDS. Grain abrasion test was tested by grain-abrasion testing machine. The results show that the microstructure of the coating is fine, uniform, free of porosity and crack. Wear resistance of the coating is 2.56 times greater than that of quenched 45# iron. There are two kinds of grain-abrasion mechanism in the metallurgical coating which are plastic deformation-remotion and rupture- spallation. The wear process is a comprehensive effect of the two kinds of mechanism. Microstructure of metallurgical coating has important effects on grain-abrasion mechanism. Excellent wear resistance of the coating is mainly due to the alloy carbide with obvious wear resistance. The alloy carbide is distributed on the matrix of solid solution.