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    Introduction of Nitrided M50 and M50NiL Bearings Into Jet Engine Mainshaft Applications

    Published: 12 December 2014

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    Although jet engine bearings are considered highly reliable, there are some applications, due to their operating conditions, which could benefit from further capability improvements beyond the traditional M50 or M50NiL materials to ensure that this high degree of reliability is maintained. Much of the challenge exists in applications where small hard particle contamination can result in surface distress to either the rolling element (ball or roller) or to the raceway and eventually cause premature bearing spallation. A program was started at GE Aviation in 1999 to improve the capability of both the M50 and M50NiL in such a contaminated type of environment. This paper will provide examples of the various test vehicles that were used to substantiate the potential improvements with the nitrided M50 and M50NiL bearing materials. This testing included evaluations from the 3 ball-on-rod, single element ball, subscale bearing, full-scale bearing, and engine tests results.


    nitriding, bearing steels, M50, M50NiL, rolling contact fatigue testing, aerospace

    Author Information:

    Rhoads, Mark
    GE Aviation, Cincinnati, OH

    Johnson, Mike
    GE Aviation, Cincinnati, OH

    Miedema, Keith
    GE Aviation, Cincinnati, OH

    Scheetz, Jon
    GE Aviation, Cincinnati, OH

    Williams, Jeff
    GE Aviation, Cincinnati, OH

    Committee/Subcommittee: A01.28

    DOI: 10.1520/STP158020140070