为了实现发动机曲轴的激光熔覆再制造修复，采用激光熔覆技术在曲轴材料45#钢样板表面制备铁基激光熔覆层，研究了熔覆层的性能，利用光学显微镜和显微硬度计进行了熔覆层金相组织观察和硬度测试。试验结果表明，熔覆层与基体结合良好，且熔覆层硬度为基体硬度的2~3倍；为了使曲轴在绕主轴颈旋转情况下对多拐曲轴连杆轴颈进行激光熔覆，提出了在连杆轴颈表面获得连续均匀熔覆层应满足的条件，并在满足这些条件的前提下，推导出了激光熔覆曲轴连杆轴颈过程中激光束与转动轴颈的运动轨迹和相对速度之间的关系模型，通过试验，验证了轨迹模型的可行性。

In order to achieve the laser cladding remanufacturing on engine crankshaft, the iron-based coating on 45# steel has been obtained by laser cladding. Properties of the cladding layers have been investigated. The morphology and microstructure of layers are observed by an optical microscope. The hardness of layers is tested by a Vickers hardness tester. It is observed that the layer and substrate has a good metallurgical bond. Average hardness of the cladding layer is 2~3 times of that of the substrate. In order to realize the laser cladding for the crankshaft rod journal while the crankshaft is rotating around the principal axis, the requirements to obtain the continuous and uniform cladding are proposed. Under the conditions, the trajectory of laser beam and rotating journal and their relative speed during laser cladding are deduced, and the feasibility of the model is verified by the experiment.