Cryogenic properties of additive manufactured austenitic stainless steels for space applications

The mechanical properties of three austenitic stainless steels alloys, namely 21-6-9, 316L and a modified 316, fabricated via laser powder bed fusion, have been studied. From the results previously obtained through tensile tests at room and cryogenic temperatures, their strength and ductility were c...

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Detalles Bibliográficos
Autor: Piantanida Colaneri, Patricio
Tipo de recurso: tesis de maestría
Fecha de publicación:2023
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/403340
Acceso en línea:https://hdl.handle.net/2117/403340
Access Level:acceso abierto
Palabra clave:Austenitic stainless steel
austenitic stainless steel
additive manufacturing
cryogenic
Acer inoxidable austenític
Àrees temàtiques de la UPC::Enginyeria dels materials
Descripción
Sumario:The mechanical properties of three austenitic stainless steels alloys, namely 21-6-9, 316L and a modified 316, fabricated via laser powder bed fusion, have been studied. From the results previously obtained through tensile tests at room and cryogenic temperatures, their strength and ductility were compared against similar conventionally processed materials. The three alloys exhibited a higher or similar strength than their conventional counterparts at both temperatures. In the case of ductility, the additive manufactured 316L was the only alloy that outperformed a conventional 316L at room temperature. At cryogenic temperature, the ductility of the three alloys was either similar or lower. Also, their plastic behavior throughout different stages of deformation was characterized from their microstructure evolution. At room temperature, a two stage, monotonically descending strain hardening rate was observed, similar to F.C.C. medium stacking fault energy materials. At cryogenic temperatures, four stages of strain hardening rates were observed, caused by a martensite transformation induced by plastic deformation, as it happens in TRIP steels.