CHARACTERIZATION OF TEMPERED MARTENSITE EMBRITTLEMENT USING HARDNESS MEASUREMENT

A series of experiments were carried out on three commerical steels to explore the possiblity for characterizing tempered martensite embritt lement (TME) by Rockwell, macro-, and micro-Vickers hardness tests. Th e results indicate distinct hardness peaks in two steels and an inflec tion in the other around the TME temperature. A new analytical approac h for examining the slope of hardness-tempering temperature plots appe ars to reveal the TME phenomenon more sensitively. Dilatometric examin ations substantiate that the temperature of hardness peak/inflection o ccurs beyond the second stage of tempering.