采用自主开发的材料体系对5CrMnMo钢堆焊层表面进行了激光合金化处理。研究了堆焊层激光合金化处理后的组织和显微硬度。在优化的工艺参数下，获得了表面光洁、与基材形成良好冶金结合的强化层。合金化层平均硬度HV750。应用于热锻模具，斯太尔曲轴切边模寿命提高了60%。研究与生产应用表明，激光制备的原位合成颗粒增强表层微观结构和激光合金化层堆焊层5CrMnMo钢基材形成连续的宏观梯度组织结构，是模具服役寿命提高的关键因素。

In this paper, laser alloying was operated on surfacing 5CrMnMo steel. Both microstructure and distribution of hardness of the material were investigated after laser alloying. Crack free and fine shaped alloying layer which was metallurgically boned with substrate was fabricated with optimization of processing parameters. The experimental results show that laser alloying with the allying material as coat improved the original microstructure evidently, and the average hardness is proved to be HV0.2750, and the lifetime of the mold significantly increased 60%. Research and practical application shows that laser producing particle reinforced composite coatings and Macrogradient structure (alloying layer surfacing5CrMnMo steel) is the key to improve life.