激光熔化沉积技术在模具修复行业有着巨大应用前景，而沉积部件的微观组织和力学性能随激光参数变化的规律对模具修复工艺窗口的选择具有重要意义。 采用激光熔化沉积技术制备了 H13 钢，研究了不同激光功率和扫描速度下 H13 钢沉积层微观组织演变及其对力学性能的影响。 结果表明， 激光功率一定时， 随着扫描速度由400 mm/min 增加到 600 mm/min ，马氏体尺寸细化，含量增加，沉积层的硬度提高约 3% 、塑性降低约 1% ，而强度先增加后减少；缺陷增多导致其与基体的结合强度下降约 20% 。扫描速度一定时，随着激光功率由 1 800 W 增加到 2 200 W ，马氏体尺寸增大、含量减少，沉积层硬度降低约 5% ，强度和塑性分别提高约 34% 和 2% ；同时缺陷减少使得结合强度提高约 58%。

Laser melting deposition technology has tremendous application prospects in the mold repair industry, and determining how the microstructure and mechanical properties of deposited parts vary with respect to the laser parameters is highly important for selecting the optimal mold repair process window. Experiments on laser melting deposition of H13 steel under different scanning speeds and laser powers were carried out, and the evolution of the microstructure and mechanical properties were analysed. The results show that as the scanning speed increases from 400 mm/min to 600 mm/min, the amount of fine martensite increases, the hardness of the deposited layer increases by approximately 3%, the plasticity decreases by approximately 1%, and the strength increases and then decreases. An increase in the number of defects leads to a decrease in the bonding strength with the substrate by approximately 20%. With increasing laser power from 1 800 W to 2 200 W, the size of the martensite increases, while the martensite content decreases. The hardness of the deposited layer decreases by approximately 5%, and the strength and plasticity increase by approximately 34% and 2%, respectively. At the same time, a decrease in the number of defects leads to an increase in the bond strength of approximately 58%.