Numerical Simulation of Temperature Field of 12crni2 by Laser Melting Deposition

Based on the heat transfer theory, and the fact that thermal physical parameters, latent heat of phase change and heat transfer coefficient which vary with temperature is taken into considered, a three-dimensional transient temperature field model of 12CrNi2 by Laser Melting Deposition (LMD) is established by using the parametric design language of ANSYS. Optimum process parameters were determined by single-layer and single-track experiments of LMD. Microstructure observation by optical microscope shows that the width of heat affected zone increased with the increase of laser power and decreased with the increase of printing speed. The top of the deposited layer is mainly composed of equiaxed dendrites, and the middle and bottom of the deposited layer are columnar crystals with epitaxial growth characteristics. At the same time, the accuracy and reliability of temperature field model are verified by comparing the morphology of molten pool. The simulation results show that in the process of LMD, the peak temperature of molten pool increases with the increase of layers; the peak temperature of the node increases with the increase of laser power and the decrease of printing speed. The research results in this paper would be reference for LMD of 12CrNi2 alloy steel.