Study On The Temperature Field And The Residual Stresses In Laser Plate Welding

Laser welding is an important part of the laser technology, which has many advantages like: less welding seam, faster welding speed, less deformation and higher precision, and has been widely used in many fields. While laser beam interacting with metal target, the metal would be melted and evaporated very soon, increasing the efficiency of metal absorbing laser energy. For the temperature gradient of laser welding is obviously higher than the traditional welding temperature gradient, it is very difficult to measure the distribution of temperature field and the distribution of the residual stress in the welding process. With computer technology developing, numerical simulation of laser welding can be worked out by computer simulation technology.This paper used the ANSYS finite element simulation software to simulate the distribution of temperature field in different laser power welding processes, the distribution of residual stress in the plate at room temperature after welding, and the spectrum of the laser welding process was measured by using the multi spectral radiation temperature measurement, the accuracy of the temperature field simulation was verified by temperature inversion. After observing the distribution of the transient temperature field and the thermal cycling of the feature points, the results show the temperature field moves timely and spatially with the heat source, and there is no longer any changes of the temperature field in the quasi steady state, and the temperature warming rate of the weld zone is obviously faster than cooling rate, what is more,the further the point peak is away from heat point,the more lower the temperature is. The distribution of the equivalent stress and the residual stress in each direction of the welding are observed. The results show that the residual stress on the board is mainly distributed around the weld seam, and the main stress is in the plate. At last, the temperature of the target is measured by using the method of multi spectral radiation temperature measurement, and the maximum temperature of the laser welding temperature field in quasi steady state is obtained and compared with the simulation results.The results of this paper provide a theoretical guidance for the laser welding, and have a fairly important reference value for selecting the optimum parameters of laser welding.