Some Effects of Friction and Lubrication During Hot Forging Steel.

  • L.J. Yates

    Student thesis: Master's ThesisMaster of Philosophy

    Abstract

    A thorough literature search showed that there is no satisfactory test to aid the selection of a lubricant in hot forging of steel. Lubricant effectiveness under difficult forging conditions has therefore been
    investigated.

    An experimental test rig was designed, developed and constructed in
    which hot specimens of temperature 900°C to 1300°C were forged. The forging condition was such that as in industry a lubricant would be used.

    Stresses were monitored by means of a Wheatstone bridge network using resistance strain gauges in conjunction with an ultra violet recorder (U.V.R.).

    The findings were critically compared with previous investigations on friction during hot forging. Relationships between the known conventional values for the co-efficient of friction and the force
    required to eject from a conical die were considered.

    reduction in the ejection load when using a lubricant was consistently demonstrated.

    The results confirmed that the concept of a simple numerical value of a co-efficient of friction, could not be applied to practical not working operations.

    Regression analysis techniques were therefore employed to examine the results in order to find relationships between variables.

    Changes in the 'slug' temperature, lubricated or dry condition and die draft angle were made and significant differences in forging loads
    were obtained.

    A method for measuring lubricant effectiveness by direct comparison
    of loads for a dry condition and lubricated condition is suggested.

    Key Words: Hot Forging - Steel - Lubrication - Friction
    Date of AwardJan 1980
    Original languageEnglish
    Awarding Institution
    • Aston University

    Keywords

    • friction and lubrication
    • hot forging steel

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