Effect of molybdenum addition on workability of powder metallurgy steels during cold upsetting

Ferrous powder metallurgy preforms containing 0%, 0.5%, 1.0% and 1.5% of molybdenum were completely investigated experimentally to study workability behaviour. The formability behaviour of the above-said powder metallurgy sintered steels preforms with aspect ratio of 0.75 under triaxial stress state condition was determined by cold upsetting them with graphite as lubricant. The formability stress parameter was evaluated for all the above-mentioned steel preforms and its variation with respect to axial strain was plotted, studied and discussed relative to their as-sintered microstructures. Also the characteristics of various stresses and stress ratio parameters with respect to axial strain were analyzed and presented.