LOW CYCLE FATIGUE BEHAVIOR AND FATIGUE CRACK INITIATION IN MAR-M247 AT 700 °C

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F17%3A00491917" target="_blank" >RIV/68081723:_____/17:00491917 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

LOW CYCLE FATIGUE BEHAVIOR AND FATIGUE CRACK INITIATION IN MAR-M247 AT 700 °C

Original language description

The second generation nickel-based superalloy MAR-M247 offers a satisfying combination of fatigue and creep properties and oxidation and corrosion resistance that are required for application at elevated temperatures in hostile environments. The microstructure consists mainly of the face centred cubic γ matrix and ordered γ´ strengthening precipitates (L12 crystal structure). The present work focuses on low cycle fatigue (LCF) behaviour of polycrystalline nickel-based superalloy MAR-M247 at high temperature. LCF tests were conducted on cylindrical specimens in a symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 700 °C in ambient air. Cyclic stress-strain curves and fatigue life curves in the representation of plastic strain amplitude vs. stress amplitude and stress amplitude vs. the number of cycles to failure, respectively, were plotted and compared with data obtained on Inconel 713LC. Special attention was paid to the investigation of crack initiation in MAR-M247 during low cycle fatigue. Crack initiation sites were studied by means of scanning electron microscopy (SEM) in dual beam microscope TESCAN LYRA 3 XMU FESEM equipped with focus ion beam (FIB). Specimens’ surface observations revealed the formation of pronounced surface relief indicating localisation of plastic deformation. Observations in transmission electron microscope (TEM) confirmed localisation of cyclic plastic deformation in persistent slip bands along {111} slip planes. Fractographic analysis revealed fatigue crack initiation sites. Fatigue crack propagation in stage I was typical of smooth facets up to 500 μm long.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

20306 - Audio engineering, reliability analysis

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

METAL 2017 - 26th International Conference on Metallurgy and Materials, Conference Proceedings

ISBN

978-80-87294-79-6

ISSN

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e-ISSN

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Number of pages

7

Pages from-to

1580-1586

Publisher name

Tanger

Place of publication

Ostrava

Event location

Brno

Event date

May 24, 2017

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000434346900255