Thermodynamics of an austenitic stainless steel (AISI-348) under in situ TEM heavy ion irradiation

Autor(es)

Tunes, Matheus A. ^[1] ; Greaves, Graeme ^[2] ; Kremmer, Thomas M. ^[1] ; Vishnyakov, Vladimir M. ^[2] ; Edmondson, Philip D. ^[3] ; Donnelly, Stephen E. ^[2] ; Pogatscher, Stefan ^[1] ; Schon, Claudio G. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Leoben, Chair Nonferrous Met, Leoben - Austria

^[2] Univ Huddersfield, Sch Comp & Engn, Huddersfield, W Yorkshire - England

^[3] Oak Ridge Natl Lab, Mat Sci & Technol Div, Oak Ridge, TN - USA

^[4] Univ Sao Paulo, Escola Politecn, Dept Met & Mat Engn, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACTA MATERIALIA; v. 179, p. 360-371, OCT 15 2019.
• Citações Web of Science: 0

Resumo

The stability of the face-centred cubic austenite (gamma-Fe) phase in a commercial stainless steel (AISI-348) was investigated through in situ transmission electron microscopy (TEM) with heavy ion irradiation at 1073 K up to a fluence of 1.3 x 10(17) ions.cm(-2) (corresponding to a dose of 46 dpa). The gamma-Fe phase was observed to decompose at a fluence of around 7.8 x 10(15) ions.cm(-2) (3 dpa) when a new phase nucleated and grew upon increasing irradiation dose. Scanning transmission electron microscopy (STEM) with energy dispersive X-ray (EDX) spectroscopy and multivariate statistical analysis (MVSA) were used to characterise the irradiated specimens. The combination of such experimental techniques with calculated equilibrium phase diagrams using the CALPHAD method led to the conclusion that the new phase formed upon irradiation is the body-centred cubic Cr-rich alpha' phase. At the nanoscale, precipitation of M23C6 (T-carbide) was also observed. The results indicate that ion irradiation can assist the austenitic stainless steel to reach a non-equilibrium state similar to a calculated equilibrium state observed at lower temperatures. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 16/25248-3 - Resolvendo a questão da escala de temperaturas em cálculos de diagramas de fases por primeiros princípios
• Beneficiário: Claudio Geraldo Schon
• Modalidade de apoio: Bolsas no Exterior - Pesquisa