You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.

    STP1600

    Subsurface Rolling Contact Fatigue of Powder Metallurgy Steels for Aerospace Bearings

    Published: 2017


      Format Pages Price  
    PDF (5.67 MB) 36 $25   ADD TO CART
    Complete Source PDF (46.7MB) 544 $155   ADD TO CART

    Cite this document

    X Add email address send
    X
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word


    Abstract

    For tomorrow’s mechanical systems—for example, in aerospace engines—bearings must meet more and more demanding requirements, such as weight savings and increased reliability. For these reasons, bearing materials must have an increased load capacity that today’s conventional metallurgy can only answer with dedicated lengthy and expensive heat treatment or a technological breakthrough. As powder metallurgy (PM) enables the realization of steel grades not obtainable by conventional metallurgy (high alloy and carbide contents, a very fine microstructure with low segregation, and above all a high hardness), and because technological improvements realized in recent years make this technology suitable for high reliability bearings, PM steel grades can be an answer to these more and more demanding requirements. ASP®2055 grade steel, with a hardened Rockwell hardness of 68HRC, was selected because of its good hardness/toughness compromise. Even though the inclusion cleanliness evaluations show that this PM steel is still not as clean as vacuum induction melted-vacuum arc remelted (known as VIM-VAR) and the best quality electric arc furnace-melted steels, the fatigue behavior rolling contact fatigue tests at 4.2 GPa yielded results with life durations similar to VIM-VAR steels. The reasons why it performed so well under elastohydrodynamic conditions, despite a limited cleanliness, were linked to both the high intrinsic microyield stress of the matrix and the presence of mixed oxide inclusions, leading to limited stress concentrations. These results were very promising for the use of PM ASP®2055 in high reliability bearings.

    Keywords:

    bearing steel, ASP, ®, 2055, powder metallurgy (PM), subsurface rolling contact fatigue (RCF), fatigue butée (FB), rolling contact fatigue, cleanliness, microstructure, oxygen content, nanoindentation, microyield stress, aerospace bearing steel


    Author Information:

    Sidoroff, Christine
    NTN-SNR Roulements, Technology and Innovation Department, Materials Laboratory E2M, Annecy,

    Lefort, Elodie
    NTN-SNR Roulements, Technology and Innovation Department, Materials Laboratory E2M, Annecy,

    Dierickx, Pierre
    NTN-SNR Roulements, Technology and Innovation Department, Materials Laboratory E2M, Annecy,

    André, Johanna
    Erasteel Kloster AB, Eramet Groupe, Products and Applications, Söderfors,

    Benbahmed, Atman
    Aubert & Duval, Eramet Group, Techniques Application, Paris,


    Committee/Subcommittee: A01.28

    DOI: 10.1520/STP160020160163