Improvement of laser hardening technology with oscillating beam using multiphysics simulation

Abstract

A simulation approach was used to improve the results of the laser hardening process of a thin-walled medium manganese steel specimen using oscillating beam technology. During the analysis of the material hardness results, it was found that the hardened zone had an irregular shape, which was the result of different thermal cycles varying with the process progress and heating of the sample. A simulation model of the laser hardening process was built to determine the proper power values to compensate for the effect of thermal inertia of the cool part. The simulation approach, in addition to the development of the master model, included the definition of the proper beam power distribution and the virtual determination of the necessary oscillation frequency that allows the equivalent linear beam distribution to be used in the calculations. The main model considered the dependence of the material properties on the phase composition of the material and was calibrated based on the results of experimental thermocouple measurements. This enabled the determination of the required power course. Using the simulation-calculated beam power, a hardening process was carried out, the results of which confirmed the successful modification of the shape of the hardened zone.