Numerical Simulation of Residual Stress Field of 50CrVA Alloy Steel Strengthened by Multi-point Laser Shock Processing

Based on the display dynamic analysis method of ABAQUS/Explicit software module, a finite element model of 50CrVA alloy steel laser shock processing was established. The convergence of relaxation duration under single-point round spot was studied to determine the relaxation duration. The distribution of residual stress in the shock region after round spot multi-point laser shock processing was studied by finite element method and compared with the test results. The distribution of stress waves during strengthening and residual stress after strengthening of round and square spot single-point laser shock processing, and the effects of laser power density and spot shape on the residual stress field during multi-point laser shock processing were analyzed by this simulation method. The results show that the determined relaxation duration was 0.000 1 s. The simulated surface residual compressive stress decreased with the increase of depth after round spot multi-point laser shock processing, and the trend was in good agreement with the test results; the relative error of the maximum residual compressive stress was 6.8%, which verified the accuracy of the finite element model. Under the same energy input condition, the shape of the spot did not affect the residual stress field after single-point laser shock processing. With the increase of the average laser power density, the maximum residual compressive stress increased. The maximum residual compressive stress (704 MPa) after square spot multi-point laser shock processing was slightly higher than that after round spot multi-point laser shock processing (692 MPa). The surface residual stress fluctuations of square spot and round spot multi-point laser shock processing were 10.9% and 12.9%, respectively, indicating that residual stress distribution after square spot multi-point laser shock processing was more uniform.