STP1465: Cleanliness of Bearing Steels and Fatigue Life of Rolling Contacts

    Kerrigan, A.
    Focus Area Expert, Engineer, and Senior Engineer, SKF Engineering Research Centre, Nieuwegein,

    Kuijpers, J. C.
    Focus Area Expert, Engineer, and Senior Engineer, SKF Engineering Research Centre, Nieuwegein,

    Gabelli, A.
    Focus Area Expert, Engineer, and Senior Engineer, SKF Engineering Research Centre, Nieuwegein,

    Ioannides, E.
    Technical Director Product R&D, SKF Group Quality & Technology Development, Nieuwegein,

    Pages: 6    Published: Jan 2007


    Abstract

    Established metallographic methods of determining the cleanliness of bearing steels with respect to micro-inclusions, such as ASTM E 45, are capable of differentiating poor quality melts from good quality melts. However, as steelmaker capabilities improve, with increasing numbers being able to consistently produce good quality melts, the established methods of cleanliness assessment are unable to differentiate between melts. These established methods, which give single figure ratings based on both the size and number of inclusions, are extremely difficult to use in predicting the performance of a bearing component under conditions of rolling contact fatigue. In this work, the method of Extreme Value Analysis (EVA) is used to characterize the inclusion population of five different steel melts of known and varying quality. A link between the EVA distribution and the measured bearing life, performed on material with a low reduction ratio, is also presented.

    Keywords:

    Extreme Value Analysis (EVA), inclusions, life prediction


    Paper ID: STP41643S

    Committee/Subcommittee: A01.13

    DOI: 10.1520/STP41643S


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