Improving metallic material properties by controlling the boundary condition of laser heat treatment

In this paper, according to theory of thermal elastoplastic and phase transformation, combined with characteristic of laser quenching, the effect of cooling velocity on temperature field and phase contents is analyzed, mathematical model of transformation during laser quenching and nonlinear heat conduction equation is presented. The computer simulation oftemperature field and distribution of volume in hardening depth after laser quenching are proposed. Also, after laser quenching experiment of 40Cr steel under case of controlling boundary condition, it can be shown that theoretic calculation fits to experimental result, and a new feasible approach is provided to improve the high-toughness of metallic material.