Numerical simulation of selective laser melting temperature conduction behavior of H13 steel in different models

Abstract

With considering the latent heat of melting and the temperature-dependent thermo-physical properties, a Gauss body heat source is employed to analyze the temperature field and the morphology of molten pool with a single-track and multi-track scan strategy in Substrate-Powder (SP) model, Full-Powder (FP) model and Partial-Solid model (PS), respectively. It is shown that the maximum temperature (Tmax) and maximum cooling rate (vcmax) of single-track increase with preheating temperature, while the maximum heating rate (vhmax) presenting an opposite trend. The preheating temperature has the greatest influence on the length and depth of the molten pool of SP model and the width of FP model. For the reason of heat accumulation, the Tmax of each track increases with the decrease of solid volume in the model and increases with the number of scan tracks in a multi-track scan strategy. Due to prominent thermal conductivity of SP model, heat accumulation of multi-track scanning has the smallest effect on the size of pool, but it drives the molten pool length of PS model and FP model increasing seriously. The verification experiment of SP model was in good agreement with the simulation results, proved that numerical simulation is capable of predicting the temperature field and molten pool morphology during the SLM process.