Tailoring the mechanical properties of additively manufactured Custom 465 martensitic stainless steel through heat treatment modification

• A modified heat treatment for additively manufactured Custom 465 achieves tensile strength comparable to wrought material, with UTS of 1773 MPa, YS of 1686 MPa, and elongation of 6.5%. • Atom probe tomography reveals that Mo atoms segregate to Ni3Ti precipitate surfaces, inhibiting precipitate growth and contributing to enhanced strength. • The study systematically investigates the effects of hot isostatic pressing, solution treatment, cryogenic treatment, and aging on microstructure and mechanical properties of L-PBF C465. • A validated yield strength calculation model is proposed, offering a predictive tool for designing heat treatments to meet diverse industrial requirements.