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Gigacycle fatigue of ultra high density sintered alloy steels

Autor(en)

Herbert Danninger, C. Xu, Golta Khatibi, Brigitte Weiss, Björn Lindqvist

Abstrakt

Sintered steel specimens with density levels of up to 7·6 g cm⁻³

have been prepared from Cr–Mo and Mo prealloyed powders. The fatigue

response has been studied using an ultrasonic resonance testing device

that enabled testing up to 10⁹ cycles. It showed that the

fatigue endurance strength can be drastically increased by raising the

density and that the sintering conditions are effective, though less

than the density. The existence of a true fatigue limit was disproved up

to 10⁹ cycles for all materials tested, with sintered steels

thus being similar to wrought ones. Cr–Mo steels was shown to be

superior to Mo alloyed grades due to the markedly finer as sintered

microstructure and higher sintering activity. Fatigue crack initiation

was found to originate from pores at first at multiple sites, with

microstructural orientation being dominant compared to the direction of

stress; with progressive loading, some cracks join to form a propagating

macrocrack from which the final failure then starts.

Organisation(en)

Physik Nanostrukturierter Materialien

Externe Organisation(en)

Technische Universität Wien, Höganäs AB

Journal

Powder Metallurgy

Band

Seiten

378-387

Anzahl der Seiten

ISSN

0032-5899

DOI

https://doi.org/10.1179/1743290112Y.0000000001

Publikationsdatum

2012

Peer-reviewed

ÖFOS 2012

210006 Nanotechnologie, 103018 Materialphysik

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