Stress sensitivity analysis of laser quenching based on regression model

Abstract

In the laser quenching process, quantitative evaluation of the influence of different process parameters on quenching stress is the key to achieve quenching process optimization. A variety of different process parameters are selected as research objects, and a parameterized thermomechanical coupling model of the disk laser hardening process for 45 steel is established. Through the calculation of the model, the instantaneous change law of stress field and the phase change field under different process parameters are obtained, and the response surface equation between the multiphysics solution results and process parameters is established. The Monte Carlo method is used to randomly sample the response equation repeated times, and the sensitivity of quenching process parameters is calculated through sampling results. The calculation result shows that hollow teardroplike stress distribution is formed in the center of the spot during quenching, and the stress around the spot is larger. Thermal stress concentration appears in the reverse direction of quenching scanning, with a maximum value of 850 MPa, and a cometlike stress zone appears in the reverse direction of quenching scanning. The diameter of the laser spot is negatively correlated with quenching stress and has the greatest influence on it. The laser incidence angle has a great influence on the depth and width of the phase change layer and is positively correlated. This model can reveal the mechanism of multifield coupling changes in the material during quenching and provide technical and theoretical support for the reasonable selection of process parameters.