Microstructure and nanoindentation of the welding zone of an experimental microalloyed steel

The effect of welding thermal cycles on microstructure of a martensite-bainite experimental microalloyed steel was analyzed. In the fusion zone, bainite and acicular ferrite microstructure is presented. In the heat affected zone, the microstructure presented is: a) bainite in the grain coarsening su...

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Autores Principales: López Martínez, Edgar, Serna, Sergio, Flores, Osvaldo, Campillo, Bernardo
Formato: Artículo
Idioma: Español
Publicado: Universidad Tecnológica de Panamá 2016
Materias:
Acceso en línea: http://revistas.utp.ac.pa/index.php/id-tecnologico/article/view/593
http://ridda2.utp.ac.pa/handle/123456789/1756
Sumario: The effect of welding thermal cycles on microstructure of a martensite-bainite experimental microalloyed steel was analyzed. In the fusion zone, bainite and acicular ferrite microstructure is presented. In the heat affected zone, the microstructure presented is: a) bainite in the grain coarsening subzone; b) polygonal ferrite in the recrystallization subzone; c) quasi-polygonal ferrite and tempering martensite in the intercritical subzone; d) tempering martensite in the subcritical subzone. By microhardness tests, a softening in the recrystallization, intercritical and subcritical subzones was observed, which is related to the microstructural features. Additionally, by nanohardness tests, hardening was observed in the boundary between intercritical and subcritical subzones, which can be attributed to a secondary hardening phenomenon due the precipitation of carbides of alloying elements. Finally, polygonal ferrite and bainite have similar behavior and nanohardness which is due the grain boundary.