Determination of heat source model for simulating full penetration laser welding of 316 LN stainless steel by computational fluid dynamics

• Published in: Materials today : proceedings Vol. 45; pp. 4465 - 4471
• Main Authors: Unni, Anoop K., Vasudevan, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2021
• Subjects: AISI 316 LN SS; Computational fluid dynamics; Keyhole laser welding; Laser heat source; AISI 316 LN SS; Computational fluid dynamics; Laser heat source; Keyhole laser welding
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2020.12.842

•Laser welding heat source models are studied using Computational Fluid Dynamics on 316 LN SS.•Temperature and melt contours determined for the heat source models.•Keyhole full penetration achieved using Conical-Cylindrical Combined (CCC) and Rotary heat source model.•CCC model is proposed based on fair agreement with experimentally measured temperature and weld bead dimensions. The selection of appropriate heat source model is vital in predicting the temperature distribution and visualizing the dynamic fluid flow behaviour during Laser keyhole welding of Type 316 LN stainless steel. Three-dimensional (3D) numerical models were designed utilizing ANSYS Fluent by employing different heat source models. Different heat source models considered include volumetric heat sources namely Goldak double ellipsoidal, 3D conical, a coalition of 3D conical and cylindrical heat source, 3D volumetric Gaussian and Rotary Gaussian. The simulation was carried out by solving the fundamental conservation equations of mass, momentum and energy. The predicted weld bead profile by different heat sources were compared with the actual weld bead obtained from the laser welding experiment on 0.0055 m thick 316 LN stainless steel (SS) plates. It was found that simulation results of the conical-cylindrical combined (CCC) model exhibited good agreement with actual weld bead dimensions and thermal data obtained during the experiment. Therefore, the conical-cylindrical heat source model is recommended for CFD simulation of full penetration laser welding of 316 LN stainless steel for studying the effect of variation of laser power and surface active element on the weld pool development.