Upper to lower bainite transition in a high-carbon low alloy steel
Carregando...
Data
Data de publicação
Autores IPEN
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
Materials Research
Exportar
Resumo
The transition from upper-to-lower bainite in carbon steels is a complex process yet not fully explored. This study examines such transition in a 0.7C, 0.74Mn, 0.61Si, 0.2Cr (wt%) low-alloy steel using a comprehensive approach that integrates dilatometry, scanning electron microscopy (SEM), ex-situ HEXRD, and microhardness testing. Microhardness and dislocation density were found strongly coupled, both increasing with decreasing austempering temperature and presenting changing trends at approximately 350°C and 300°C. Likewise, an Arrhenius plot derived from the curves of transformed fraction as a function of austempering temperature presented the same behaviour. These turning points are considered, respectively, the onset and the end of the transitional interval between upper and lower bainite. Furthermore, SEM analyses confirmed a progressive change in morphology, from coarse upper bainite at high temperatures (400°C), to a mixture of upper and lower bainite in the transitional range, and finally to exclusively fine lower bainite at low temperatures (275°C). The results support that the upper-to-lower bainite transition is not a discrete step but a continuum and offer insights into the interplay between bainite morphology, overall transformation kinetics, and microhardness, which are critical for optimizing heat treatments routes.
Como referenciar
SOUZA, SAMUEL da S. de; MANFRINATO, MARCOS D.; MORAES, NATHANAEL W. S.; CENTENO, DANY M. A.; GOLDENSTEIN, HELIO. Upper to lower bainite transition in a high-carbon low alloy steel: linking overall transformation kinetics, microstructure and microhardness. Materials Research, v. 29, p. 1-9, 2026. DOI: 10.1590/1980-5373-MR-2025-0634. Disponível em: https://repositorio.ipen.br/handle/123456789/50163. Acesso em: 04 Nov 2026.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.