CFD-based modelling of phase transformation in laser welded low-carbon steel

Abstract This paper presents a numerical model of the laser welding steel, taking into account heat and mass flows, as well thermal effects associated with phase transformations. It was assumed that source is symmetrical power distribution TEM 10 beam in two condition variants: stationary moving at constant speed along sample. After reaching melting temperature, movement liquid forced by Marangoni effect acting on surface pool. For applied, pool to be flat. proposed an algorithm for forecasting changes during heating cooling. Diffusive transformations cooling were modelled using Johnson-Mehl-Avrami-Kolmogorov (JMAK) equations. Diffusionless occurring when rates exceed critical ones Koistinen-Marburger (KM) Calculations made rectangular sample welded air cooled spontaneously atmosphere. The boundary conditions simulated assuming coefficient exchange radiation environment. start end time calculated based average rate temperature range 800–500°C ( v 8/5 ). tested test material: S355J2 steel.