Influence of Carbon Content on Strain Hardening Behaviour of Sintered Plain Carbon Steel Preforms

Complete experimental investigation on the instantaneous strain hardening behaviour of powder metallurgy (P/M) preforms of pure iron, Fe-0. 35%C, Fe-0. 75%C and Fe-1. l%C was carried out. The strain hardening behaviour of the above-mentioned P/M sintered steel preforms with aspect ratio of 0. 4 under triaxial stress state condition was determined by cold upsetting under nil/no and graphite lubricant conditions. The instantaneous strain hardening value (ni), strength coefficient (Ki), and the stress as a function of strain and densification were obtained and analyzed. Furthermore, a relation was obtained from a semi-log plot of stress against relative density and analyzed to study the hardening behaviour owing to densification as stress was a function of induced strain as well as densification in the P/M materials.