| Popis: |
In order to reduce the stresses and cracks generated during the progress of laser cladding and improve the fatigue resistance and service life of the die steel, a simulation study of residual stresses and surface texture is attempted by changing the parameters of the cladding process. Different melting process parameters (power, scanning speed, spot radius) are selected as laser melting simulation factors and the residual stress is used as the main experimental index in this paper. Three-factor, three-level orthogonal simulation experiments are conducted to determine the optimal melting parameters by performing signal-to-noise ratio and extreme difference analysis on the experimental results. The cladding temperature and residual stress distribution are compared between prefabricated texture and non-texture cladding simulation under the optimal cladding parameters. The results of the optimal melting parameters are as follows: laser power of 800 W, scanning speed of 20 mm/s, spot radius of 1 mm, and the minimum residual stress of 360 MPa. In the melting simulation, the average residual stress of the prefabricated clad layer is 149 MPa, which is about 58.56% lower than that of the nonwoven simulation. In addition, the experimental results are in accordance with the simulated results and validate that the residual stresses may be reduced by the prefabricated texture under the premise of ensuring the melting temperature, which in turn can achieve the purpose of reducing the crack generation. |
