A three dimensional (3D) finite element model for simulating pulsed laser
surface hardening is established, in which laser
spatial and time-dependent intensity distribution, temperature-dependent thermophysical properties of material, microstructural evolution and multi-phase transformations are considered. For the two cases that
thermophysical parameters are assumed to be constant, and are variable with temperature as well as latent heat is taken into account, temperature field and its evolution are validated with analytical method and general finite element software package MSC/NASTRAN, respectively. The hardening depth and width are verified with experimental ones. The influence of material thermophysical properties on hardened zone is investigated, and the regularity of relationship between hardening depth and thermophysical parameters in certain zone is obtained, i.e., hardening depth increases under invariable heat conductivity and decreases under invariable specific heat capacity with the increase of thermal diffusivity, and decreases with the increase of heat conductivity and specific heat capacity for given thermal diffusivity. Taking example for ductile iron, eutectoid steel and medium carbon steel, two methods to determine material thermophysical constants, i.e. mean value method and adopting parameters nearby austenitizing temperature method are explored, and results indicate that the mean value method can gain better predication.