Title: Numerical simulation of melting and solidification in laser welding of mild steel

Authors: M. Sundar, A.K. Nath, D.K. Bandyopadhyay, S.P. Chaudhuri, P.K. Dey, D. Misra

Addresses: School of Laser Science and Engineering, Jadavpur University, USIC Building, Kolkata 700032, India. ' Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur – 721302, India. ' School of Laser Science and Engineering, Jadavpur University, USIC Building, Kolkata 700032, India. ' School of Laser Science and Engineering, Jadavpur University, USIC Building, Kolkata 700032, India. ' School of Laser Science and Engineering, Jadavpur University, USIC Building, Kolkata 700032, India. ' School of Laser Science and Engineering, Jadavpur University, USIC Building, Kolkata 700032, India

Abstract: Melting and solidification which is mainly responsible for weld pool geometry in a laser welding process is analysed following two different transient models: (1) without fluid flow, that is, pure conduction and (2) with surface tension driven flow considering various beam power, beam diameter and scanning speed. Based on these models, numerical simulations for laser welding of mild steel has been carried out using commercial software, Fluent. By solving the conservation equations of energy, momentum and mass, the temperature distribution, liquid fraction and flow fields has been predicted and the fusion zone and Heat Affected Zone (HAZ) were obtained. Using predicted results, this present study investigates the effects of laser beam power, beam diameter and scanning speed on heat transfer and the weld pool geometry. Analysis shows that the effect of consideration of fluid motion has pronounced effects on the thermal field and weld pool geometry. [Received 20 January 2007; Accepted 14 September 2007]

Keywords: laser welding; modelling; Marangoni force; numerical simulation; surface tension force; melting; solidification; mild steel; weld pool geometry; temperature distribution; liquid fraction; flow fields; fusion zone; heat affected zone; HAZ; laser beam power; beam diameter; scanning speed; heat transfer.

DOI: 10.1504/IJCMSSE.2007.017926

International Journal of Computational Materials Science and Surface Engineering, 2007 Vol.1 No.6, pp.717 - 733

Published online: 23 Apr 2008 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article