This project aims to provide a better understanding of the structural integrity of remanufactured steel components using WAAM. The primary focus is on residual stress mitigation and part-substrate interfacial strength evaluation. The first objective is to better understand the effect of process and geometrical parameters on residual stresses. A novel experimentation procedure based on digital image correlation will be developed to demonstrate its capability for the quantification of residual stresses. The second objective is to better understand the WAAM part-substrate interfacial properties based on thorough mechanical characterization (static and dynamic). A novel numerical approach considering interfacial strength heterogeneity to predict fatigue life will be developed. Finally, the third objective is to study the feasibility of a non-conventional post-deposition treatment (pneumatic impact treatment or PIT) on improving fatigue lifetime.