STP1195: Rolling Contact Bearing Steel for Operation at 120 to 250°C

    Chu, H
    Senior engineers and professor, Central Iron and Steel Research Institute, Beijing,

    Chen, C
    Senior engineers and professor, Central Iron and Steel Research Institute, Beijing,

    Yang, J

    Pages: 12    Published: Jan 1993


    Abstract

    Differential dilatometric testing results show that the composition strengthening of chromium, silicon, tungsten, and vanadium increases the stability of overcooled austenite, shifting the T-T-C curve to the right and lowering the Ms point, thus an air-hardening phenomenon occurs. Phase analysis indicates that, in the quenched state, all of the silicon and one third of the tungsten dissolve into solid solution. This increases the softening resistance of martensite upon tempering and increases the transformation temperature as well, so that the tempering temperature range of the second stage is broadened. Addition of vanadium and tungsten changes the type, particle size, and distribution of carbides. The mutual action of the matrix and carbides makes the steel, GCrSiWV, tempered at 300°C, have superior tempering stability, dimensional stability, hot hardness, and high temperature contact fatigue life. The fatigue life, L10 of GCrSiWV steel at 250°C, is six or four times higher than that of GCrl5 or M50 steel, respectively.

    Keywords:

    medium temperature bearing steel, solid solution, tempering stability, retained austenite, carbide, contact fatigue life


    Paper ID: STP24834S

    Committee/Subcommittee: A01.28

    DOI: 10.1520/STP24834S


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