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Degradation of nanostructured bainitic steel under rolling contact fatigue


Type

Article

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Authors

Solano-Alvarez, W 
Pickering, EJ 
Bhadeshia, HKDH 

Abstract

The consequences of rolling contact fatigue on carbide-free nanostructured bainite intended for bearing applications are presented for the first time. Tests performed at various intervals followed by mechanical, microscopical, and crystallographic characterisation lead to the conclusion that the degradation mechanism is ductile void formation at interfaces, followed by growth and coalescence into larger voids that lead to fracture along the direction of the softer phase. This is di↵erent from the conventional damage mechanism that involves crack initiation at inclusions and propagation, for example in typical bearings steels such as 52100. The huge density of interfaces in the nanostructure allows the formation of a large dispersion of voids, and ultimately cracks, at depths consistent with the maximum orthogonal shear stress which occurs below the contact surface. This study should prove useful for the eventual usage of nanostructured bainitic steels in rolling bearings.

Description

Keywords

Nanostructured bainite, Rolling contact fatigue, Structural degradation, Void formation, Bearing steel

Journal Title

Materials Science and Engineering: A

Conference Name

Journal ISSN

0921-5093
1873-4936

Volume Title

617

Publisher

Elsevier BV
Sponsorship
Funding by CONACyT, the Cambridge Overseas Trust, and the Roberto Rocca Education Programme is highly appreciated and acknowledged.