Hydrogen-based ore-to-part manufacturing of near-net shaped stainless steel

Decarbonizing iron and steelmaking, combined with global disruptions to raw material supply chains, necessitates novel approaches to iron and steel production. In this work, we demonstrate a direct ore-to-part manufacturing route using a mixture of ore-derived oxide powders of Fe ₂ O ₃ , Cr ₂ O ₃ , NiO, and MoO ₃ as feedstock for additive manufacturing, combined with sintering under H ₂ to produce a near-net shaped austenitic stainless-steel. Complete reduction of all constituent oxides, including MoO ₃ and Cr ₂ O ₃ , is achieved in-situ at 1300°C, resulting in dense, crack-free bulk alloy. The fabricated part retains geometric fidelity while undergoing substantial volumetric shrinkage inherent to redox and sintering. Thermodynamic calculations elucidate the co-reduction mechanisms and alloying pathways that enable complete metallization. This work is the first demonstration of net-shaping metal parts directly from ore derived oxides, and this ore-to-part approach can minimize the emissions and lead time for manufacturing associated with downstream processing such as rolling, forging, and machining.