Kinetic Study to Predict Sigma Phase Formation in Duplex Stainless Steels

dc.contributor.authordos Santos D.C.
dc.contributor.authorMagnabosco R.
dc.date.accessioned2019-08-20T00:17:37Z
dc.date.available2019-08-20T00:17:37Z
dc.date.issued2016
dc.description.abstract© 2016, The Minerals, Metals & Materials Society and ASM International.This work presents an improved kinetic study of sigma phase formation during isothermal aging between 973 K and 1223 K (700 °C and 950 °C), based on Kolmogorov-Johnson-Mehl-Avrami (K-J-M-A) model, established from volume fraction of sigma phase determined in backscattered electron images over polished surfaces of aged samples. The kinetic study shows a change in the main mechanism of sigma formation between 973 K and 1173 K (700 °C and 900 °C), from a nucleation-governed stage to a diffusion-controlled growth-coarsening stage, confirmed by a double inclination in K-J-M-A plots and microstructural observations. A single inclination in K-J-M-A plots was observed for the 1223 K (950 °C) aging temperature, showing that kinetic behavior in this temperature is only related to diffusion-controlled growth of sigma phase. The estimated activation energies for the nucleation of sigma phase are close to the molybdenum diffusion in ferrite, probably the controlling mechanism of sigma phase nucleation. The proposed time-temperature-transformation (TTT) diagram shows a “double c curve” configuration, probably associated to the presence of chi-phase formed between 973 K and 1073 K (700 °C and 800 °C), which acts as heterogeneous nuclei for sigma phase formation in low aging temperatures.
dc.description.firstpage1554
dc.description.issuenumber4
dc.description.lastpage1565
dc.description.volume47
dc.identifier.citationD. C. dos Santos; R. Magnabosco. Kinetic Study to Predict Sigma Phase Formation in Duplex Stainless Steels. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, v. 47, p. 1, 2016.
dc.identifier.doi10.1007/s11661-016-3323-z
dc.identifier.issn1073-5623
dc.identifier.urihttps://repositorio.fei.edu.br/handle/FEI/2299
dc.relation.ispartofMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
dc.rightsAcesso Restrito
dc.titleKinetic Study to Predict Sigma Phase Formation in Duplex Stainless Steels
dc.typeArtigo
fei.scopus.citations62
fei.scopus.eid2-s2.0-84961285519
fei.scopus.subjectBackscattered electron images
fei.scopus.subjectControlling mechanism
fei.scopus.subjectDiffusion controlled growth
fei.scopus.subjectDuplex stainless steel
fei.scopus.subjectHeterogeneous nucleus
fei.scopus.subjectMicro-structural observations
fei.scopus.subjectSigma phase formation
fei.scopus.subjectTime temperature transformation diagrams
fei.scopus.updated2024-02-01
fei.scopus.urlhttps://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84961285519&origin=inward
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