Genetic design of precipitation-hardening stainless steels for additive manufacturing

A genetic algorithm for the design of precipitation-hardening (PH) stainless steels (SSs) for additive manufacturing (AM) is presented. A fully martensitic matrix is found to be the key factor for achieving the maximum strength but, unlike earlier studies, in situ ageing treatment unique to AM is al...

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Detalles Bibliográficos
Autores: Sabzi, H.E., Lim, S.H., Crociata, D.D., Castellote-Alvarez, R., Simonelli, M., San-Martín, David, Hao, Xinjiang, Choi, Pyuck-Pa, Rivera-Díaz-del-Castillo, P.E.J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/366569
Acceso en línea:http://hdl.handle.net/10261/366569
Access Level:acceso abierto
Palabra clave:Precipitation hardening steels
Additive manufacturing
Laser powder bed fusion
Cu-rich precipitates
Atom probe tomography
Descripción
Sumario:A genetic algorithm for the design of precipitation-hardening (PH) stainless steels (SSs) for additive manufacturing (AM) is presented. A fully martensitic matrix is found to be the key factor for achieving the maximum strength but, unlike earlier studies, in situ ageing treatment unique to AM is also taken into consideration, leading to the promotion of precipitation of Cu-rich precipitates during AM. Design theories are integrated to a genetic algorithm optimisation framework to maximise strength and printability. Experimental proof of concept was made by fabricating the novel alloy components using laser powder bed fusion (LPBF) AM, and was compared to a commercial LPBFed 17-4 PH SS. The results are consistent with the goals of the design strategy. The superior mechanical properties of the designed alloy were attributed mainly to a combination of two factors: precipitation hardening and dislocation strengthening. Precipitation hardening, controlled by a high dislocation density of the matrix as a result of dislocation multiplication and annihilation during printing, is the main responsible for the improvement of yield strength of the LPBFed novel PH SS.