Li Linjie, Cui Quanwei, Zhou Jianxing, Lu Zhicheng, Sun Haoran, Jiang Hong, Guo Wanli, Wu An
School of Mechanical Engineering, Xinjiang University, Urumqi 830047, China.
Goldwind Science and Technology Co., Ltd., Beijing 100010, China.
Materials (Basel). 2024 Sep 28;17(19):4769. doi: 10.3390/ma17194769.
In order to explore the influence of laser power on the evolution of molten pool and convective heat transfer of laser cladding Incoloy 926 on stainless steel surface, a three-dimensional thermal fluid multi-field coupled laser cladding numerical model was established in this paper. The variation of latent heat during solid-liquid phase transformation was treated by apparent heat capacity method. The change in the gas-liquid interface was tracked using the mesh growth method in real time. The instantaneous evolution of temperature field and velocity flow field of laser cladding Incoloy 926 on a stainless steel surface under different laser power was discussed. The solidification characteristic parameters of the cladding layer were calculated based on the temperature-time variation curves at different nodes. The mechanism of the impact of laser power on the microstructure of the cladding layer was revealed. The experiment of laser cladding Incoloy 926 on 316L surface was carried out under different laser power. Combined with the numerical simulation results, the effects of laser power on the geometrical morphology, microstructure and element distribution of the cladding layer were compared and analyzed. The results show that with the increase in laser power, the peak temperature and flow velocity of the molten pool surface both increase significantly. The thermal influence of the molten pool center on the edge is enhanced. The temperature gradient, solidification rate, and cooling rate increased gradually. The microstructure parameters (G/R) are relatively small when the laser power is 1000 W. In the experimental range, the dilution rate and wetting angle of the cladding layer both increase with the increase in laser power. When the laser power is 1000 W, the alloying elements of the cladding layer are more evenly distributed and the microstructure is finer. The experimental results are in good agreement with the simulation results.
为了探究激光功率对不锈钢表面激光熔覆因科洛伊926熔池演变及对流换热的影响，本文建立了三维热流体多场耦合激光熔覆数值模型。采用显热容法处理固液相变过程中的潜热变化。利用网格生长法实时跟踪气液界面的变化。讨论了不同激光功率下不锈钢表面激光熔覆因科洛伊926的温度场和速度流场的瞬时演变。基于不同节点的温度-时间变化曲线计算了熔覆层的凝固特征参数。揭示了激光功率对熔覆层微观组织影响的机制。在不同激光功率下进行了316L表面激光熔覆因科洛伊926的实验。结合数值模拟结果，对比分析了激光功率对熔覆层几何形貌、微观组织和元素分布的影响。结果表明，随着激光功率的增加，熔池表面的峰值温度和流速均显著增加。熔池中心对边缘的热影响增强。温度梯度、凝固速率和冷却速率逐渐增大。当激光功率为1000W时，微观组织参数（G/R）相对较小。在实验范围内，熔覆层的稀释率和润湿角均随激光功率的增加而增大。当激光功率为1000W时，熔覆层的合金元素分布更均匀，微观组织更细小。实验结果与模拟结果吻合良好。
