Finite Element Method Analysis of Stress Field Considering Thermal Coupled Force During Laser Process

According to the prominent characteristic of rapid heating and cooling velocity in process of laser phase transformation hardening, it is important and necessary to consider the couple relation among temperature, phase transformation and stress. Based on the above, a mathematical model to analyze transformation and to reflect its characteristic is presented. Also temperature field control equation relative to stress and phase transformation is set up and thermal elastoplastic constitutive equation containing phase transformation was derived, In a given yield condition, temperature and stress field are numerically calculated by means of Finite Element Method. The result indicates the calculation value coincides with result of test Stress especially thermal stress varied violently in process of laser phase transformation hardening, which leaded to the residual stress on the surface and accorded to the fact. This process can improve the characteristic of material, so it is significant to study on thermal stress of laser quenching, to discuss the effect of phase transformation and stress on temperature, to optimize the laser quenching process and to improve the synthetic mechanic properties of quenching material.