A review of post-processing techniques for additive manufactured stainless steel: Enhancing surface quality and mechanical properties

Additive Manufacturing (AM) enables the fabrication of stainless steel (SS) components with complex geometries; however, as-built parts often exhibit high surface roughness, residual stresses, porosity, and microstructural anisotropy, which limit their mechanical performance and service reliability. The objective of this review is to critically evaluate post-processing strategies for AM stainless steels and assess their effectiveness in mitigating these inherent deficiencies. Mechanical, chemical, thermal, and hybrid post-processing techniques applied to various AM SS grades are systematically analyzed with respect to surface integrity, porosity reduction, residual stress evolution, microstructural modification, and mechanical property enhancement. The governing mechanisms of material removal, plastic deformation, diffusion, and phase transformation are discussed, highlighting the strengths and limitations of each approach. The analysis reveals that no single post-processing method provides a universal solution; instead, application-specific and hybrid approaches often yield superior performance through synergistic effects. It is concluded that optimized integration of post-processing with AM process control is essential for achieving high-performance SS components. Future research should focus on in situ monitoring, process parameter optimization, and microstructure-informed AM strategies to minimize post-processing requirements and enable more sustainable and cost-effective production of SS components.