Volume 3, Issue 2 (February 2006)

    Characterization of Wear and Surface Reaction Layer Formation on Aerospace Bearing Steel M50 and a Nitrogen-alloyed Stainless Steel

    (Received 29 April 2005; accepted 30 August 2005)

    Published Online: 2005

    CODEN: JAIOAD

      Format Pages Price  
    PDF Version 10 $25   ADD TO CART


    Abstract

    The formation of reaction layers on surfaces in mechanical contact is strongly affected by the tribological loading conditions, the materials used, the lubricant and the service temperature. An appropriate balance between reactivity of material and lubricant in tribological systems decreases wear and friction and increases the durability. The goal of this paper is to compare the reaction layer formation on a standard aerospace bearing steel AMS 6491 (M50) with that on a high strength stainless steel grade AMS 5898 exhibiting a nominal chemical compositions of 0.82C-4.1Cr-1V-4.2Mo (wt. %) and 0.3C-0.4N-15.2Cr-1Mo (wt. %), respectively. As lubricant jet engine oil Mobil Jet II has been used. Rolling contact fatigue (contact pressure: 6 GPa) and ball-on-disk tests (contact pressure: 1.6 GPa, sliding speed 10 cm/s) at room temperature and at 150°C were employed to study the effect of extreme loading conditions and temperature dependence of the reaction layer formation. The contact areas were inspected by means of optical profilometry, scanning electron microscopy (SEM), and secondary ion mass spectrometry (SIMS) in order to determine type, thickness, homogeneity, and distribution of the reaction layers in the contact zone. The main result of the study is that the reaction layer formation is significantly less on the stainless steel grade compared with M50. SIMS depth profiles were determined in order to explain the differences in the wear characteristics of the two materials. The reaction layers are mainly built up of PXOY molecules, which might be phosphates resulting from the tricresyl phosphate (TCP) lubricant additive. The role of the chemical reaction of the steel and TCP regarding the layer formation will be discussed.


    Author Information:

    Peissl, S
    Materials Center Leoben,

    Leitner, H
    University of Leoben,

    Ebner, R
    Materials Center Leoben,

    Hutter, H
    Institute for Chemical Technologies and Analytics, Vienna University of Technologies, Vienna,

    Krecar, D
    Institute for Chemical Technologies and Analytics, Vienna University of Technologies, Vienna,

    Rabitsch, R
    Boehler Edelstahl GmbH, Kapfenberg,


    Stock #: JAI14055

    ISSN: 1546-962X

    DOI: 10.1520/JAI14055

    ASTM International is a member of CrossRef.

    Author
    Title Characterization of Wear and Surface Reaction Layer Formation on Aerospace Bearing Steel M50 and a Nitrogen-alloyed Stainless Steel
    Symposium Bearing Steel Technologies: Seventh International Symposium, 2005-05-19
    Committee A01