Numerical Simulation And Experimental Study On The Laser Surface Hardening Of H13

With the rapid development of manufacturing industry, the mold has become the main molding tool, the requirement for the quality of mould also rises increasingly.H13 is the main raw material of die casting mould. It is difficult to improve the anti fatigue strength of the surface when using the traditional physical surface treatment method because of the deformation of the work piece, And on the basis of using the laser surface hardening in overcoming this difficulty, mechanical properties of the mold can be further improved surface hardness, wear resistance, thermal stability, fatigue resistance and the critical fracture toughness, etc. Laser surface hardening technology can be affected by many factors and parameters. It is difficult to specify the changing process through the experimental analysis of laser phase transformation hardening layer. According to the finite element analysis method, this paper makes the numerical simulation the temperature field of the process of the laser surface quenching, predict the depth of hardened layer by using the temperature field results, and select the same parameters to make comparative experiments with that of the numerical simulations.Make experiments on laser hardening artifacts H13 by using the CO2 laser surface processing system to verify the accuracy of the simulation results prediction of the hardened layer.This paper takes H13 (4Cr5MoV1Si) as the analysis object of hot work die steel. It uses the finite element method to simulate the transient process and distribution of laser surface hardening process H13 rectangular piece of temperature field. It analyzes the laser scanning process the changing rules of the temperature field of the model through selecting different laser processing parameters,According to the temperature field in the austenitic phase prediction transformation hardening layer depth and workpiece isotherm ayer width, it analyzes the hardening type distribution uniformity on the whole and presents the method to improve the uniformity of the distribution of the hardening. The following conclusions:1.H13 layer depth of laser surface hardened is proportional to the laser power and is inversely proportional to laser scanning speed and the diameter of the laser.2.The different sample thickness of H13, have a certain impact on the workpiece temperature, the greater the smaller the influence of the thickness, the higher the temperature in the depth direction.3.Constant velocity of laser scanning will cause the over shallowness and deepness of the workpiece out end of hardening layer. And the sectional scanning technology can improve the longitudinal uneven distribution of the hardening layer. Changing the laser spot energy distribution shape and making the uniform energy distribution of light spot can increase the cross section at the spot edge depth of hardened layer4. Through the numerical simulation data compared with the experimental results.The is that H13 laser surface hardening obtained hardened layer simulation results can provide some reference to the experimental results. The accuracy needs to be further improved.