溶质再分配系数对激光熔覆溶质分布的影响  

Effect of Solute Redistribution Coefficient on Solute Distribution in Laser Cladding

作　　者：张曹伟 葛鸿浩 方豪 张群莉[1,2,3] 姚建华 Zhang Caowei;Ge Honghao;Fang Hao;Zhang Qunli;Yao Jianhua(College of Mechanical Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310014,China;Institute of Laser Advanced Manufacturing,Zhejiang University of Teclmology,Hcmgzhou,Zhejiang 310014,China;Collaborative Innovation Center of High-End Laser Manufacturing Equipment,Hangzhou,Zhejiang 310014,China)

机构地区：[1]浙江工业大学机械工程学院,浙江杭州310014 [2]浙江工业大学激光先进制造研究院,浙江杭州310014 [3]高端激光制造装备省部共建协同创新中心,浙江杭州310014

出　　处：《中国激光》2022年第2期123-134,共12页Chinese Journal of Lasers

基　　金：国家自然科学基金(51804274,52035014);浙江省属高校基本科研业务费专项资金资助项目(RF-C2019003)。

摘　　要：为了提高沉积层溶质分布的预测精度,研究溶质再分配系数对沉积层溶质分布的影响机制,本研究团队将体积平均法和非平衡溶质再分配系数计算方法相结合,分别建立动态溶质再分配系数凝固模型和恒定溶质再分配系数凝固模型,模拟45钢表面316L不锈钢涂层的激光熔覆过程,分析熔覆过程中的流动、传热和传质现象。结果表明:两种模型预测的温度场分布、熔池形貌、熔池流场等结果的差异性并不明显,但在元素分布方面,动态溶质再分配系数凝固模型的误差更小,更接近实验结果。分析后认为,溶质再分配系数在沉积层溶质分布过程中起主导控制作用,动态溶质再分配系数更接近真实的熔池凝固过程,从而使预测准确性更高。Objective Laser cladding technology, which is the foundation of laser remanufacturing technology, can improve the wear resistance, corrosion resistance, high-temperature resistance, and other properties of the substrate surface. However, the experimental method requires a significant amount of time and energy to optimize the parameters of laser cladding, and numerical simulation provides an efficient way to study such a complex physical phenomena. Moreover, laser cladding is a non-equilibrium solidification process, but most of the numerical simulations have neglected it. This study demonstrates a three-phase solidification model based on the volume-averaged method and investigates the influence of the solute redistribution coefficient on the solute distribution in the deposition layer during non-equilibrium solidification. Additionally, accurate prediction of the solute distribution on the deposition layer has also been presented in this study during the laser cladding.Methods A three-phase solidification model based on the volume-averaged method is established in this study, with considerations of non-equilibrium dynamic solute redistribution coefficient and constant solute redistribution coefficient. Both models investigate the laser cladding of 316 L stainless steel powder on 45 steel substrates. The experimental results on the geometrical morphology and chromium concentration of the cladding layer validate the numerical results. By comparing the temperature field, flow field, and solute field of the two models, the influence of the solute redistribution coefficient on the cladding process during non-equilibrium solidification is explored;furthermore, whether the dynamic solute redistribution coefficient should be considered in the solidification model is determined by comparing the prediction accuracy of chromium concentration between the two solidification models.Results and Discussions In this paper, the mass of element mesh diffusion is used to calculate the relatively accurate moving velocity of the soli

关 键 词：激光技术 激光熔覆 溶质再分配系数 溶质分布 数值模拟 

分 类 号：TN249[电子电信—物理电子学] TG111.4[金属学及工艺—物理冶金]