【摘要】 利用电子显微技术和力学性能测试 ,研究了Q2 35低碳钢基体上激光熔覆Co基合金的凝固组织及其形成过程 ,讨论了熔覆层合金成分和显微硬度变化规律。结果表明 ,基体和熔覆层之间形成了良好的冶金结合 ;熔覆区的组织不均匀 ,随着距交界面距离的增加 ,由胞状晶和逆热流方向外延生长的粗大树枝晶变为较细小的树枝晶 ,最终过渡到表层的细小树枝晶和等轴晶 ,熔覆层断口以沿晶断裂为主 ,激光熔覆对合金成分的稀释作用小更多还原

【Abstract】 In this paper,the solidification features and formation law of microstructure for cobalt based alloy on the substrate of Q235 by laser cladding have been studied by using electron microscopy and mechanical property tests.The metallurgical bonding between substrate and cladding layer is well.The microstructure at the cladding layer bottom was cellular crystal and the typical coarse dendrite crystal.The dendrite crystal becomes smaller and the cell crystal disappeared along the distance from the substrate increased.The microstructure on the top is the fine dendrite and equiaxed crystal.The cladding has characteristic of intercrystalline fracture.The extent of dilution by laser cladding is small.更多还原