• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Master's Dissertation
DOI
https://doi.org/10.11606/D.3.1994.tde-12042022-133853
Document
Author
Full name
Claudio Geraldo Schön
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 1994
Supervisor
Committee
Goldenstein, Helio (President)
Landgraf, Fernando Jose Gomes
Rechenberg, Hercilio Rodolfo
Title in Portuguese
Estudo microestrutural da austenita de uma liga de ferro contendo 8% de cromo e 1,2% de carbono.
Keywords in Portuguese
Aço
Carbono
Materiais
Abstract in Portuguese
Austenitas encontradas em aços são comumente descritas como soluções sólidas homogêneas desordenadas. Um estudo recente, entretanto, iniciou que esta imagem não é correta para o sistema 'Fe'-'Cr'- C, de grande importância tecnológica. No presente trabalho, as técnicas de difração de nêutrons em amostra policristalina e espectroscopia Mossbauer por elétrons de conversão foram empregadas para investigar a estrutura ordenada da austenita de uma liga 'Fe'-8%'Cr'-1,2% C solubilizada a 1473 kelvin durante 200 horas. Os resultados confirmam a distribuição do cromo segundo um supereticulado de estequiometria ferro sete cromo. Quanto ao carbono, os resultados contradizem a sua distribuição nos interstícios octaédricos do supereticulado, embora a análise do espectro Mossbauer indique forte repulsão entre os intersticiais e sua concentração na vizinhança dos átomos de cromo. Estes resultados são compatíveis com uma distribuição ordenada a longo alcance tanto do cromo quanto do carbono nesta liga.
Title in English
Microstructural study of the austenite in an iron, 8wt% chromium, 1,2wt%.
Keywords in English
Carbon
Materials
Steel
Abstract in English
Microstructural study of the austenite in an iron, 8wt% chromium, 1.2 wt% carbon alloy. Steel austenites are usually described as homogeneous disordered solid solutions. A recent study indicates, however, that this picture is no longer valid for the technologically important Fe-Cr-C system. In this work, neutron powder diffraction and conversion electron Mössbauer spectroscopy were used to investigate the ordered structure of an Fe-8wt%cr-1.2wt%C austenite. The results confirm the distribution of chromium in an 7 chromium stoichiometry superlattice. The carbon distribution does not agree with an octahedral interstitial occupancy, although the Mössbauer spectrum analysis indicates a strong repulsion between interstitials and an enrichment of the neighbourhood of chromium with carbon. These results are compatible with long-range order both of chromium atoms and of carbon atoms.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
Publishing Date
2022-04-12
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
CeTI-SC/STI
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2022. All rights reserved.