Angle- and energy- dispersive diffraction used to determine stress evolution in 17-4 PH steel produced by ADAM process and subjected to SMAT

In this study, the evolution of residual stress and elastic anisotropy in 17-4 PH stainless steel produced by Atomic Diffusion Additive Manufacturing (ADAM) and subjected to Surface Mechanical Attrition Treatment (SMAT) was investigated. Angle- and energy-dispersive X-ray diffraction techniques were employed to analyze the residual stress profiles in both the as-built and SMAT-treated samples. The results reveal that SMAT introduces compressive residual stresses while refining the material's microstructure. Residual stress analysis indicates that the as-built sample exhibits tensile stresses near the surface, which gradually decrease with depth. In contrast, the SMAT-treated sample shows compressive stresses, ranging from -200 MPa at the surface to -600 MPa in deeper regions. This study highlights the critical role of selecting an appropriate grain interaction model for X-ray Stress Factors (XSFs) calculation to ensure accurate residual stress characterization, which is essential for the reliability and performance of additively manufactured components, particularly in high-stress applications.