The Effect of Forging Reduction on the Properties of a Die Steel

  • R.N. Bayliss

    Student thesis: Master's ThesisMaster of Science (by Research)


    The literature dealing with the effect of forging reduction
    upon mechanical properties and service performance, with particular
    reference to hot work steels, has been reviewed. The effect
    of forging reduction on mechanical properties and the service
    performance of BSS.224 No. 5. nickel-chromium-molybdenum hot
    work die steel has been studied by processing a 34=ton electrically
    melted ingot, forged in three stages, with forging reductions of
    2.92, 9.0 and 18.5/1 respectively. From each bloom six die
    inserts were manufactured to a hardness range of 363/388 B.H.N.
    The life of the die inserts was compared with routine production
    data. The effect of forging reduction on mechanical properties,
    measured in three mutually perpendicular testing directions, was
    investigated at room temperature.

    The variation of properties is related to the distribution
    and form of non-metallic inclusions, and not to heterogeneity
    which, although apparently present on metallographic examination,
    was not confirmed by chemical and micro-probe analyses. Even so
    the micro hardness varied in a random manner. Increasing forging
    reductions did not affect mechanical properties measured in the
    longitudinal direction. Transverse and depth properties were
    impaired by heavier amounts of forging, but not to the same extent that other workers have previously reported. Forging had no
    influence upon die life except that heavy reduction minimised
    scatter. Room temperature mechanical properties do not appear to
    have a bearing on die life.

    The published conversion tables of hardness and tensile
    strength were found to be inapplicable to the range of hardness
    Date of Award1967
    Original languageEnglish


    • reduction
    • forging
    • die steel
    • metallurgy

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