Effect of shot blasting parameters on corrosion resistance and de-rusting effectiveness in welded zones

Welded zones often show poor de-rusting results due to geometric discontinuities and metallurgical inhomogeneity. While shot blasting can effectively treat these areas, most studies focus on flat base metals and lack a systematic analysis of process parameters. In this study, immersion corrosion tests, shot blasting experiments, and electrochemical tests were performed on welded specimens to assess the effect of blasting duration on corrosion resistance. A finite element model was developed to evaluate the influence of blasting velocity, diameter, and angle on de-rusting effectiveness. Results show that corrosion resistance first improves and then declines with longer blasting time, suggesting an optimal blasting duration. Velocity, diameter, and angle were identified as the main factors affecting rust removal, roughness, and residual stress, with blasting angle having the most significant overall impact and thus deserving priority in process optimisation.