等离子堆焊铌元素增强镍基合金堆焊层的组织与性能

Microstructure and performance of nickel-based alloy with niobium coating through plasma surfacing

利用等离子堆焊技术在304L钢板表面制备了添加Nb粉的Ni40合金堆焊层,并对堆焊层的微观组织、显微硬度和耐磨性进行研究。结果表明,堆焊层组织主要由γ-Ni树枝晶、枝晶间的共晶组织、弥散分布的Nb C颗粒、硼化物和碳化物等相组成。由于增强相Nb C颗粒在堆焊层中均匀分布,使Nb/Ni40复合合金堆焊层与纯Ni40合金堆焊层相比,显微硬度提高约40%(平均达到448 HV0.3),耐磨性也提高约37.5%。

Ni40 alloy with the niobium powder doped composite was coated on 304 L steel substrate by plasma transferred arc surfacing( PTA). The microstructure,microhardness and wear-resistance of the coated layer with the doped niobium powder were investigated. The microstructure of the coating consists of mainly γ-Ni dendrite,interdendritic eutectics,dispersed Nb C particles,borides and carbides.Due to the dispersed precipitation phase Nb C,the microhardness and wear-resistanceof the coated layer with the niobium powder doped are increased by 40% and 37. 5% than that of the pure Ni40 coated layer.