多道激光熔覆铁基合金的组织和性能

Microstructure and Property of Multirun Laser Cladding Fe-base Alloy

在球铁基体上激光熔覆铁基合金,对多道搭接时激光熔池的凝固速率、"二次加热"效应以及熔体的对流行为对搭接熔覆层组织、成分、性能的影响进行了分析。结果表明,搭接熔覆获得的熔覆层组织随扫描次序前后而粗大,稀释率逐渐增加,硬度值相应降低。搭接熔覆层组织分界不明显,与基体结合处为波形界面,达到冶金结合。

Fe-base alloy was cladded by laser on spheroidal graphite cast iron substrate. The effects of the freezing rate of laser molten pool, secondary-heating affect and fusant convection in multirun overlapping on the microstructure, component and property of cladding layer were analyzed. The results show that, with the increase of scanning times of the laser cladding, the microstructure of overlapping cladding layers becomes more coarser, the dilution increases gradually, the microhardness decreases accordingly. No obvious microstructure interfaces in the overlapping coating are observed and the interface between the coating and substrate shows metallurgical combining.