Development, Post Processing and Characterization of Additive Manufactured Stainless Maraging Steel

A high strength Fe–Cr–Co–Ni–Mo stainless maraging steel was realized through additive manufacturing using Laser powder bed fusion (LBPF) technique. As a part of post processing, effect of different heat treatment cycles with and without hot isostatic pressing (HIPping) was studied. The as-printed coupons, subjected to sub-zero treatment and direct aging, were found to meet the specified properties in comparison with other multi-stage heat treatment conditions. Conventional heat treatment cycle exhibited highest strength with fine martensitic structure and HIPed specimens exhibited isotropic properties compared to the un-HIPed specimens. HIPping is found to improve the ductility of material as well, however with a reduced strength by 5–10% owing to grain coarsening in post-HIPping operation.