Analysis of the influence of surface texture on properties of laser cladding layer on die steel

In order to reduce the phenomenon of greater stress and cracks during the progress of laser cladding, improve the fatigue resistance and service life after laser cladding, and extend its service life. Laser power (800, 1000, 1200 W), scanning speed (5, 10, 20 mm/s), spot radius (0.5, 0.75, 1 mm) are selected as simulation factors for laser cladding, and the residual stress is taken as the main experiment indicator during the three-factor and three-level orthogonal simulation experiments. The S/N and range analysis are performed on simulation results to determine the optimal laser cladding parameters. Comparing the cladding temperature and residual stress distribution between prefabricated texture and non-texture cladding simulation under the optimal cladding parameters, and the cladding process is performed under the optimal parameters to verify its validity. The orthogonal simulation experiments show that the optimal cladding parameters of 800 W laser power, 20 mm/s scanning speed, 0.1 mm spot radius, and the minimum residual stress is 360 MPa under the optimal cladding parameters. In addition, the laser power has the most significant influence on residual stress, followed by spot radius, the scanning speed has the least influence on residual stress. The laser cladding simulation of prefabricated texture on die steel results the average residual stress of 149 MPa, which reduces by 58.56% compared with the value of non-texture cladding simulation under the optimal cladding parameters. The effectiveness of the method is verified by measuring the residual stress after the laser cladding processing on the textured and non-textured steel surface. The method of prefabricating surface texture reduces the residual stress under the premise of ensuring the cladding temperature, which verifies the feasibility and superiority of prefabricating surface texture, and finally achieving the purpose of reducing residual stress and cracks. © 2021, Chongqing Wujiu Periodicals Press. All rights reserved.