304LN表面沉积异质合金过程多组元传输行为数值模拟  

Numerical Simulation of Multi-element Transport Behavior during Surface Deposition of Heterogeneous Alloy in 304LN

作　　者：赵天碕 赵吉宾[1,3] 何振丰 王志国[1,3] 赵宇辉[1,3] 陈燕[2] ZHAO Tianqi;ZHAO Jibin;HE Zhenfeng;WANG Zhiguo;ZHAO Yuhui;CHEN Yan(Shenyang Institute of Automation,Chinese Academy of Sciences,Shenyang 110016,China;School of Mechanical Engineering and Automation,University of Science and Technology Liaoning,Liaoning Anshan 114051,China;Institute for Robotics and Intelligent Manufacturing,Chinese Academy of Sciences,Shenyang 110169,China)

机构地区：[1]中国科学院沈阳自动化研究所,沈阳110016 [2]辽宁科技大学机械工程与自动化学院,辽宁鞍山114051 [3]中国科学院机器人与智能制造创新研究院,沈阳110169

出　　处：《表面技术》2024年第19期141-152,共12页Surface Technology

基　　金：国家自然科学基金(52105415);国防科技重点实验室基金(61420052022KJW05);辽宁省自然科学基金计划项目(2022-MS-040);沈阳市中青年科技创新人才支持计划项目(RC220527);“兴辽英才计划”青年拔尖人才(XLYC2203154)。

摘　　要：目的探究在304LN不锈钢表面上激光沉积Stellite 6合金过程中的多元素传输机制。方法采用流体体积法VOF(Volume of Fluid),建立气-液两相传热传质激光沉积模型。模型中使用改进VOF法对熔池表面进行追踪,结合多组分传输模型与熔凝杠杆原则(Lever Rule),对异质材料熔覆界面的多元素传输进行模拟,采用扫描电子显微镜(SEM)与能谱仪(EDS)观察组织结构和元素分布,对比模拟结果分析多组沉积层宏观形貌和元素分布特征。结果沉积过程中,熔池的流动与材料导热对温度的传输起着重要作用,前端对流不断地将已熔化的基材金属运输至熔池中部,后端对流则将卷积的Fe元素和Co元素进一步混合。最终沉积层的宏观形貌平均误差为2.67%,主要元素Fe、Co、Cr的质量分数误差分别为0.64%、1.27%、0.31%。结论Fe元素浓度整体区域分布相对均匀,但在沉积层底部,Fe元素浓度迅速升高,Co元素浓度随沉积深度加深逐渐降低,Cr元素在沉积层中部富集的分布特性。该优化后的模型可以准确模拟异质合金沉积过程中的温度场、流场与质量传输过程。The work aims to investigate the multi-element transport mechanism during laser deposition of Stellite 6 alloy on the surface of 304LN stainless steel.In this study,the Volume of Fluid(VOF)method was employed to simulate the heat conduction and flow characteristics of the melt pool,and the multi-element transport processes,aiming to investigate the principles of multiple elements diffusion in the deposited layer and the distribution characteristics of strengthening phases.Firstly,a two-phase solidification 2D model based on the VOF method was developed,taking into account the element transport model and the melting-solidification lever rule.The model was used to investigate the distribution mechanism of three main elements during deposition of Stellite 6 cobalt alloy powders on a 304LN stainless steel substrate.Then,transient temperature distribution and flow field data at different locations were obtained.Finally,the calculated geometrical shapes and element distributions under different processing parameters were found to be in good agreement with experimental results.The accurate identification of the liquid-vapor interface area was achieved by tracking the gradient differences of second phase volume fraction in the computational grid.Here,the thermal properties of the material were defined based on a mixture rule,taking into account the reaction time of the mechanical arm servo.Compared to multiple experimental results,the average geometric shape error was 2.67%,and the mass score error of the main elements was 0.64%(Fe),1.27%(Co),and 0.31%(Cr).Moreover,a comet tail-like temperature field was observed at the rear end of the melt pool,resulting in Marangoni convection caused by temperature gradients,and leading to the further mixing of various elements.At the same time,the distribution characteristics of three main elements in the deposited layer varied.Due to the effect of Marangoni convection,the distribution of Fe element was relatively uniform in the overall region,but the concentration sharply increased i

关 键 词：表面沉积 多组分传输 元素分布 热量传输 钴基合金 

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]