激光熔覆获得稳定熔池的工艺优化

Optimization of the Laser Cladding Process for Stable Molten Pool Size

建立了三维有限元模型,分析了316L不锈钢在激光熔覆过程中的温度场分布以及相变规律。结合材料性质随温度变化的特性,讨论了冷却过程中金属的相变规律。采用能量按高斯分布的移动热源,通过在激光熔覆单道熔覆层过程中不断调整激光功率以及激光束移动速度来保证熔池形状的稳定。结果显示,在给定基体温度初始值下,不同激光束移动速度下的激光功率大小与熔覆层层数都近似呈线性相关,同时模拟了熔池周围的温度分布以及冷却速率,并与试验结果进行了比较。

A three dimensional finite element model was established for the analysis of temperature distribution and phase evolution of 316L stainless steel in the laser cladding process. The influence of phase transition is discussed by using temperature dependent material qualities as well as cooling transformation diagram. A moving heat source with Gaussian en ergy distribution is established. The laser power and laser beam movement speed are optimized during the single-channel laser cladding to ensure the steady shape of molten pool. We found that the relation between laser power and laser beam movement speed is approximate linearly related. Besides, predicted the temperature distribution and cooling rate in comparison with experiments.