Mechanical behavior of welded plates of austenitic low-density Fe-Mn-Al-C steels microalloyed with Ti/B by microtensile testing

The present study investigates the microstructural evolution and mechanical behavior of an austenitic low-density Fe-27Mn-7Al-1.2 C steel microalloyed with Ti/B after autogenous gas tungsten arc welding (GTAW). Microtensile specimens were extracted from the fusion zone (FZ) and two heat-affected zon...

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Detalhes bibliográficos
Autores: Coronado Alba, Carlos Enrique, Mejía, Ignacio, Cabrera Marrero, José M.|||0000-0001-8417-1736
Tipo de documento: artigo
Data de publicação:2026
País:España
Recursos:Universitat Politècnica de Catalunya (UPC)
Repositório:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglês
OAI Identifier:oai:upcommons.upc.edu:2117/455893
Acesso em linha:https://hdl.handle.net/2117/455893
https://dx.doi.org/10.1007/s00170-025-17374-x
Access Level:Acesso embargado
Palavra-chave:Low-density steel
Welding
Microtensile test
Mechanical properties
Strain hardening exponent
Strain hardening rate
¿-phase
Àrees temàtiques de la UPC::Enginyeria dels materials
Descrição
Resumo:The present study investigates the microstructural evolution and mechanical behavior of an austenitic low-density Fe-27Mn-7Al-1.2 C steel microalloyed with Ti/B after autogenous gas tungsten arc welding (GTAW). Microtensile specimens were extracted from the fusion zone (FZ) and two heat-affected zones (HAZ-1 and HAZ-2) and evaluated through optical and electron microscopy, electron backscattered diffraction (EBSD), X-ray diffraction (XRD), and Vickers microhardness testing. The welded joint exhibited dendritic austenite in the FZ and equiaxed austenite with ¿-carbide precipitation in the HAZs. The FZ showed the lowest mechanical performance (YS 395 MPa, UTS 534 MPa, elongation 45%), whereas HAZ-1 and HAZ-2 exhibited strengthening associated with ¿-carbides and TiC/AlN precipitates (UTS up to 671 MPa). Strain-hardening analysis using Hollomon and Ludwick models indicated a higher hardening capacity in the HAZs. The findings demonstrate how welding thermal cycles control precipitation, microstructural morphology, and mechanical response in LD steels, providing insight for improved weldability and performance of lightweight structural components.