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Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy

INTRODUCTION: Super-Duplex Stainless Steeles (SDSS) proved an excellent potential for its use in many chemical and offshore applications due to their both high mechanical properties and a high corrosion resistance in chloride ion solutions. OBJECTIVES: This study evaluates the influence of ageing tr...

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Autores principales: Cojocaru, Elisabeta Mirela, Raducanu, Doina, Nocivin, Anna, Cojocaru, Vasile Danut
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8132198/
https://www.ncbi.nlm.nih.gov/pubmed/34026286
http://dx.doi.org/10.1016/j.jare.2020.11.005
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author Cojocaru, Elisabeta Mirela
Raducanu, Doina
Nocivin, Anna
Cojocaru, Vasile Danut
author_facet Cojocaru, Elisabeta Mirela
Raducanu, Doina
Nocivin, Anna
Cojocaru, Vasile Danut
author_sort Cojocaru, Elisabeta Mirela
collection PubMed
description INTRODUCTION: Super-Duplex Stainless Steeles (SDSS) proved an excellent potential for its use in many chemical and offshore applications due to their both high mechanical properties and a high corrosion resistance in chloride ion solutions. OBJECTIVES: This study evaluates the influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy. METHODS: The influence of ageing treatment on microstructural features was analysed by SEM-EBSD (Scanning Electron Microscopy - Electron Backscatter Diffraction) technique, while on mechanical properties by tensile and impact testing techniques. RESULTS: The obtained results show that for the short duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/γ grains boundary by the δ → σ precipitation, while for long duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/δ grains boundary, or in other favourable nucleation sites, due to the eutectoid decomposition δ → σ + γ(2). Experimental data showed that at low temperatures, i.e. 780 °C, in order to induce the precipitation of σ-phase, the minimum incubation time is situated close to 20 min, and that increasing treatment temperature decreases the minimum incubation time, with at 850 °C and 920 °C the σ-phase being firstly detected at 5 min. The σ-phase precipitation shows the highest precipitation kinetics at 850 °C, when the maximum weight-fraction is obtained for each treatment duration when compared with ageing treatments performed at 780 °C and 920 °C. CONCLUSION: All presented data brings valuable insight into the σ-phase precipitation phenomena and its influence on UNS S32750 SDSS alloy’s exhibited mechanical properties and, also, can provide researchers and industrial steel processors a guide regarding the selection of optimal ageing treatment parameters to avoid/minimise the embrittlement induced by the precipitation of deleterious σ-phase.
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spelling pubmed-81321982021-05-21 Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy Cojocaru, Elisabeta Mirela Raducanu, Doina Nocivin, Anna Cojocaru, Vasile Danut J Adv Res Mathematics, Engineering, and Computer Science INTRODUCTION: Super-Duplex Stainless Steeles (SDSS) proved an excellent potential for its use in many chemical and offshore applications due to their both high mechanical properties and a high corrosion resistance in chloride ion solutions. OBJECTIVES: This study evaluates the influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy. METHODS: The influence of ageing treatment on microstructural features was analysed by SEM-EBSD (Scanning Electron Microscopy - Electron Backscatter Diffraction) technique, while on mechanical properties by tensile and impact testing techniques. RESULTS: The obtained results show that for the short duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/γ grains boundary by the δ → σ precipitation, while for long duration ageing treatments the σ-phase nucleates, within the δ-phase matrix, at the δ/δ grains boundary, or in other favourable nucleation sites, due to the eutectoid decomposition δ → σ + γ(2). Experimental data showed that at low temperatures, i.e. 780 °C, in order to induce the precipitation of σ-phase, the minimum incubation time is situated close to 20 min, and that increasing treatment temperature decreases the minimum incubation time, with at 850 °C and 920 °C the σ-phase being firstly detected at 5 min. The σ-phase precipitation shows the highest precipitation kinetics at 850 °C, when the maximum weight-fraction is obtained for each treatment duration when compared with ageing treatments performed at 780 °C and 920 °C. CONCLUSION: All presented data brings valuable insight into the σ-phase precipitation phenomena and its influence on UNS S32750 SDSS alloy’s exhibited mechanical properties and, also, can provide researchers and industrial steel processors a guide regarding the selection of optimal ageing treatment parameters to avoid/minimise the embrittlement induced by the precipitation of deleterious σ-phase. Elsevier 2020-11-14 /pmc/articles/PMC8132198/ /pubmed/34026286 http://dx.doi.org/10.1016/j.jare.2020.11.005 Text en © 2020 The Authors. Published by Elsevier B.V. on behalf of Cairo University. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Mathematics, Engineering, and Computer Science
Cojocaru, Elisabeta Mirela
Raducanu, Doina
Nocivin, Anna
Cojocaru, Vasile Danut
Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title_full Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title_fullStr Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title_full_unstemmed Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title_short Influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of UNS S32750 SDSS alloy
title_sort influence of ageing treatment temperature and duration on σ-phase precipitation and mechanical properties of uns s32750 sdss alloy
topic Mathematics, Engineering, and Computer Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8132198/
https://www.ncbi.nlm.nih.gov/pubmed/34026286
http://dx.doi.org/10.1016/j.jare.2020.11.005
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