Magalhães, Charles Henrique Xavier MoraisFaria, Geraldo Lúcio deLagoeiro, Leonardo EvangelistaSilva, Jéssica Dornelas2017-11-132017-11-132017MAGALHÃES, C. H. X. M. et al. Characterization of the austenite reformation mechanisms as a function of the initial ferritic state in a UNS S32304 duplex stainless steel. Materials Research-Ibero-american Journal of Materials, v. 21, p. 1-10, 2017. Disponível em: <http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-14392017005043108&lng=es&nrm=iso>. Acesso em: 29 set. 2017.1516-1439http://www.repositorio.ufop.br/handle/123456789/9132Aiming to better understand the effects of heat treatment parameters on Ferrite-Austenite phase transformation in a 2304 duplex stainless steel different thermal cycles were applied to this steel in a quenching dilatometer. The obtained microstructures were characterized by optical microscopy, transmission electron microscopy and electron backscatter diffraction. It was noticed that the austenite formation mechanism is strongly dependent on initial ferritized state. If the initial structure is completely ferritized, the nitrogen supersaturated solid solution leads to chromium nitrides precipitation and the rate of austenite nucleation decreases. For higher cooling rates, the ferrite grain boundaries control the austenite nucleation rate. The higher the ferrite grain size, the lower the final austenite fraction. If the steel is cooled from a partial ferritized state, the ferrite-austenite phase boundaries work as austenite nucleation site and the austenite growth rate is favored due to the high interfacial energy and the austenitic structures becomes coarser.en-USabertoDuplex stainless steelFerrite austenitePhase transformationArtigo publicado em periodicoO periódico Materials Research dá permissão ao RI/UFOP para depositar uma cópia eletrônica dos artigos publicados por esse periódico em que ao menos um dos autores é aluno ou professor da UFOP. Contato via email em 25 out. 2013.https://doi.org/10.1590/1980-5373-mr-2016-1122