Authors: Dvořák, Jiří ; Král, Petr ; Kvapilová, Marie ; Hrbáček, Karel ; Sklenička, Václav
Document type: Papers
Conference/Event: Metal 2018 - International conference on metallurgy and materials /27./, Brno (CZ), 20180523
Year: 2018
Language: eng
Abstract: Two cast and heat-treated NbC and TaC – strengthened cobalt superalloys have been developed for a precision casting of spinner discs for glass wool industry. In this work constant load creep tests in tension were carried out in argon atmosphere at three testing temperature 900, 950 and 1000 °C and at the initial applied stresses ranged from 40 to 200 MPa. All the tests were continued until the final fracture. The results of creep testing were combined with microstructural and fractographic examinations by means of light and scanning electron microscopy. A mutual comparison of creep characteristics of the investigated superalloys under comparable creep loading conditions showed that NbC-strengthened superalloy exhibited longer creep life than TaC-strengthened one. Further, it was found that carbide precipitation is the primary strengthening mechanism in both cobalt-base superalloys under investigation and the amount, morphology\nand type of carbides have the decisive effect on the creep properties including creep damage and fracture processes. By contrast, NbC-superalloy exhibited a more brittle character of creep fracture mode than TaCstrengthened superalloy. This study was initiated to investigate in more details creep deformation processes and the effect of the creep microstructure and damage evolution on both investigated superalloys. The different behaviour and properties of studied superalloys were explained based on the received results of this study.
Keywords: carbide precipitation; Co-based superalloys; creep tests; damage process; microstructure evolution
Project no.: FV10699, LM2015069 (CEP), ED1.1.00/02.0068
Funding provider: GA MPO, GA MŠk, GA MŠk
Host item entry: Metal 2018 - 27th International conference on metallurgy and materials, Conference Proceedings, ISBN 978-80-87294-84-0

Institution: Institute of Physics of Materials AS ČR (web)
Document availability information: Fulltext is available at the institute of the Academy of Sciences.
Original record: http://hdl.handle.net/11104/0291961

Permalink: http://www.nusl.cz/ntk/nusl-391454

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Research > Institutes ASCR > Institute of Physics of Materials
Conference materials > Papers
 Record created 2019-02-13, last modified 2022-09-29

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