Influence of Adjusted Melt Pool Geometries on Residual Stress in 316L LPBF Processes

Residual stress remains a significant challenge in the widespread adoption of the Laser Powder Bed Fusion (LPBF) process, due to its detrimental impact on dimensional accuracy and post-processing requirements and hinders further processing with methods such as welding. Different strategies have already been explored to reduce or mitigate these stresses, including preheating, alternating scan strategies, and heat treatments. In this study, a less commonly investigated approach is examined: the influence of melt pool geometry—specifically layer height and track width—on the residual stresses in LPBF-manufactured 316L stainless steel. By systematically varying these parameters, the resulting internal stress states are compared by distortion measurements of cantilever parts to determine potential correlations and mechanisms of influence. The findings aim to contribute to a deeper understanding of process–structure–property relationships in LPBF and to offer a new avenue for stress control through geometrical process parameter optimization. It can be concluded that among all the strategies for preventing and mitigating residual stress in LPBF, the examined approach has a relatively small influence. The results show that increasing layer thickness and decreasing spot diameter have beneficial effects on the resulting deformations.