Multifaceted mechanical and tribological characterisation of wire arc additive manufactured SS410 martensitic stainless steel

SS410 stainless steel is widely used in demanding applications, including piston rings and steam turbine blades, due to its high strength and wear resistance. However, conventional manufacturing methods are constrained by limited geometric flexibility and material inefficiency. Wire Arc Additive Manufacturing (WAAM) offers a cost-effective alternative capable of producing complex geometries with reduced material waste. This study investigates the microstructural features and mechanical properties of WAAM-fabricated SS410 walls across different regions. Mechanical anisotropy was observed, with horizontally oriented specimens exhibiting higher strength than vertically oriented specimens. The horizontal samples achieved an ultimate tensile strength of 1015 ± 13 MPa and yield strength of 866 ± 6 MPa, compared with 934 ± 17 MPa and 790 ± 8 MPa, respectively, for the vertical samples. Conversely, vertical specimens showed better ductility, with elongation values of 19.65 ± 1.4% compared with 16.48 ± 0.8% for horizontal specimens. Hardness decreased from top (351 ± 23 HV) to bottom region (252 ± 15 HV). Microstructural analysis revealed martensite, retained austenite (RA), and δ-ferrite, with RA content decreasing from bottom to top. Fractography confirmed predominantly ductile failure, while WAAM-fabricated SS410 demonstrated a modulus of rupture of 831 MPa, highlighting its suitability for high-performance industrial applications.