Response of ferrite, bainite, martensite, and retained austenite to a fire cycle in a fire-resistant steel

Autor(es):Mostrar menos -

Escobar, J. D. ^[1] ; Delfino, P. M. ^[1] ; Ariza-Echeverri, E. A. ^{[1, 2]} ; Carvalho, F. M. ^[3] ; Schell, N. ^[4] ; Stark, A. ^[4] ; Rodrigues, T. A. ^[5] ; Oliveira, J. P. ^[5] ; Avila, J. A. ^[6] ; Goldenstein, H. ^[1] ; Tschiptschin, A. P. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Met & Mat Engn Dept, Av Prof Mello Moraes 2463, Sao Paulo - Brazil

^[2] Univ Tecnolag Pereira, Escuela Tecnol Mecan, Carrera 27 10-02 Alamos, Pereira - Colombia

^[3] Inst Technol Res, Met Proc Lab, Av Prof Almeida Prado 532, Sao Paulo - Brazil

^[4] Helmholtz Zentrum Hereon, Inst Mat Phys, Max Planck Str 1, D-21502 Geesthacht - Germany

^[5] Univ NOVA Lisboa, NOVA Sch Sci & Technol, Dept Mech & Ind Engn, UNIDEMI, P-2829516 Caparica - Portugal

^[6] Sao Paulo State Univ, UNESP, Campus Sao Joao da Boa Vista, Sao Joao Da Boa Vista, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MATERIALS CHARACTERIZATION; v. 182, DEC 2021.
• Citações Web of Science: 0

Resumo

Understanding the kinetics of microstructural degradation during the event of a fire is of major relevance to future optimization of fire-resistant steels (FRS). In this work, we use in situ synchrotron X-ray diffraction to assess the rapid thermally-assisted degradation of different starting microstructures, such as (i) ferrite + pearlite; (ii) bainite + retained austenite, and (iii) martensite + retained austenite, during the simulation of a fire cycle in a Fe-0.13C-0.11Cr-0.38Mo-0.04V FRS. Our results show that retained austenite is the most unstable phase, especially when generated by faster cooling rates, decomposing at temperatures as low as 180 degrees C during fire simulations. Bainite and martensite are both unstable and undergo recovery and carbon desaturation via secondary precipitation of cementite. However, bainite is comparatively more stable than martensite since its decomposition starts at 400 degrees C, while for martensite it occurs at 320 degrees C. We also present a methodology to deconvolute the effect of temperature on the increased background and signal intensities of the X-ray spectra, allowing the direct observation of the kinetics of secondary cementite precipitation. (AU)

• Processo FAPESP: 18/21251-5 - Caraterização do efeito de endurecimento secundário ativado por temperatura de aços resistentes ao fogo durante a simulação de incêndios
• Beneficiário: Julian David Escobar Atehortua
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 17/17697-5 - Avaliação mecânica e microestrutural de peças fabricadas por manufatura aditiva no aço 18%Ni Maraging 300 com aplicação aeronáutica.
• Beneficiário: Julian Arnaldo Avila Diaz
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 19/00691-0 - Avaliação microestrutural de partes fabricadas por manufatura aditiva para aplicação aeronáutica
• Beneficiário: Julian Arnaldo Avila Diaz
• Modalidade de apoio: Auxílio à Pesquisa - Regular