Strain hardening behaviour in forming of sintered iron-0.35% carbon powder metallurgy preform during cold upsetting

A complete experimental investigation on the instantaneous strain-hardening behaviour of powder metallurgy preforms of Fe-0.35%C was carried out. The strain hardening behaviour of the above-mentioned P/M sintered steel preforms with aspect ratio of 0.4 and 0.6, respectively, under triaxial stress state condition was determined by cold upsetting under nil/no and graphite lubricant conditions. The instantaneous strain hardening value (n i), strength coefficient (Ki), and the stress as a function of strain and densification were obtained and analyzed. Further, a relation is obtained from a semi-l...