摘要
根据传热学和流体力学基本原理建立瞬态Nd:YAG脉冲激光焊接熔池三维数值分析模型,研究Hastelloy C-276合金薄板脉冲激光焊接过程中熔池液态金属流动的基本规律.利用Fluent软件,采用有限容积法求解控制方程,用SIMPLE算法处理压力与速度耦合.引入Ma来评价焊接熔池的流动特性,并指出了焊接熔池中出现重熔轮廓线的原因.通过与实测温度场对比,验证了所建模型的准确性.模拟分析表明:脉冲激光焊接过程中存在较微弱的Marangoni对流现象;牛顿剪切应力的存在使熔池表层流体对流剧烈.此模型可为Hastelloy C-276合金薄板脉冲激光焊接熔池流体流动行为分析提供理论依据.
A transient three-dimensional model of pulsed laser welding is established based on the theories of fluid dynamics and heat transfer to investigate the fundamental rules of the fluid flow in thin Hastelloy C-276 alloy welding pool welded by the pulsed Nd ：YAG laser . The algorithm of SIMPLE is adopted to deal with the coupling of velocity and pressure .Finite volume method is used to solute the control equation ,and Ma is employed to analyze the characteristics of convection in the welding pool .Furthermore ,the reason of forming the contours of multiple remelting and solidification is given .The calculated results are compared with the experimental ones ,which testifies the accuracy of the model .The weak Marangoni convection occurs during the process of pulsed laser welding .The existence of New ton shear stress leads to the intensive convection on the top surface of the molten pool .The model can provide a theoretical basis for the analysis of the fluid flow in the weld pool during pulsed laser welding of thin Hastelloy C-276 alloy .
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
2014年第1期49-53,共5页
Journal of Dalian University of Technology
基金
"九七三"国家重点基础研究发展计划资助项目(2009CB724307)
国家自然科学基金资助项目(51175061)
