中文摘要：

用Nd：YAG脉冲激光在低硅钢表面制备激光熔覆高硅涂层，研究了激光熔覆高硅涂层样品的组织和磁性能．结果表明，制备出的激光熔覆高硅涂层组织致密、无气孔和裂纹，且与基体有良好的冶金结合．经激光熔覆后硅钢表面存在熔覆区、界面结合区和热影响区．熔覆区的显微组织不均匀，随着与结合界面距离的增加，由柱状晶变为树枝晶，最终过渡到表层的细小树枝晶组织．熔覆层与基体之间的结合界面为平面晶组织，热影响区为马氏体组织．熔覆涂层的显微硬度远高于低硅钢基体，其主要原因是涂层具有较高的Si含量，涂层中的α—Fe和γ-Fe双相组织也导致了硬度的提高．激光熔覆高硅涂层硅钢样品经扩散退火后具有室温铁磁性，Si含量的提高使其室温直流磁性能优于原始低硅钢．

英文摘要：

A pore and crack-free coating with dense microstructure and high Si content was produced on low silicon steel surface by Nd：YAG laser. The metallurgical bonding between the coating and the substrate was also realized. After cladding, the surface of silicon steel could be divided into the cladding zone, interface zone and heat-affected zone. In the cladding zone, the microstructure is mainly composed of columnar dendrites, dendrites and fine dendrites with increasing the distance from the interface. The interface zone is planar crystallization morphology and the heat-affected zone is acicular martensite microstructure. As a result of the high Si content and the presence of α-Fe and γ-Fe duplex phases in the cladding coating, the microhardness of the coating is much higher than that of low silicon steel substrate. Magnetization experiments reveal that the cladding and annealing specimen with higher magnetic properties at 298 K due to the higher Si content.