采用激光熔覆技术在45#钢表面制备不同成分的铁基涂层，对比分析熔覆层的组织特征及性能。结果表明，激光处理后截面分为熔覆层、热影响区和基体三个区域，且熔覆层与基体呈冶金结合。激光熔覆层由底部到表层依次由柱状树枝晶、少量的柱状树枝晶和树枝晶、细小的树枝晶以及M23C6型碳化物组成。X射线衍射结果表明，随着B4C和Ti含量增大，奥氏体含量逐渐降低，马氏体含量逐渐增加，熔覆层的显微硬度和耐蚀性能逐渐提高。但当Ti含量达到4.5%时，组织发生明显变化，由底部到表层由少量的胞状树枝晶、细小树枝晶和梅花状树枝晶组成，且熔覆层硬度及耐蚀性最佳。

The Fe-based coatings with different compositions are produced on 45# steel by laser cladding technology, and the structure and property are analyzed. The results show that the cross section is composed of cladding coating, heat affected zone and the matrix after laser treatment, and the interface between cladding coating and the matrix is metallurgical bonding. The laser cladding coating is composed of columnar crystal, a little columnar crystal and fine dendrite, fine dendrite and carbides of type M23C6 from the bottom to surface. X-ray diffration results show that the content of austenite decreases and the content of martensite increases with the increment of B4C and Ti, while the microhardness and corrosion resistance are improved. However, when the Ti content reaches 4.5%, the structure changes obviously. Which is composed of a little cellular dendrite, fine dendrite and dendrite with plum blossom shape from the bottom to surface, and the hardness and corrosion resistance are best.