Numerical and experimental assessment of residual stresses in wire arc additive manufactured S316L steel single-track walls

Transient thermal loads of wire Arc Additive Manufacturing (WAAM) leads to nonuniform expansions and contractions of the material, and formation of residual stresses. Residual stresses negatively impact the material performance and dimensional accuracy. To mitigate the negative effects of the residual stresses, it is crucial to understand their evolution mechanisms during the process. This study, therefore, investigates residual stress evolutions during WAAM of S316L single-track walls utilizing numerical and experimental methods. The results show that the highest and lowest residual stresses form perpendicular to the build direction, in the travel and transverse directions, respectively. Highest residual stress in the build direction were observed at the ends of the wall, which explains high cracking probability at these regions. Releasing the clamp and removing the substrate significantly reduce the residual stress level. Different fixturing methods, substrate materials and geometries influence deformation and residual stress of the component.