The effects of extrusion and rolling variables on the quality and mechanical behavior of a powder metallurgy chromium-magnesium oxide composite have been studied.nHot rolling at 2200° F and finish rolling at 900° F with reductions of 40 to 55 percent provided sound, contamination free sheet having a ductile-brittle transition temperature of 45° F in the recrystallized condition. Oxidation, erosion and nitridation behavior were observed to be improved over unalloyed chromium. Preliminary studies have indicated that a strain aging phenomenon may be responsible for the brittle behavior observed with as rolled and stress relieved sheet. Further work is required to resolve this anomaly.nThe results of this initial program have indicated that the full potential of chromium composites can be realized with additional development directed toward strengthening, and further retardation of nitrogen diffusion at elevated temperature.
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