Deformation behaviour of sintered high carbon alloy powder metallurgy steel in powder preform forging

Powder preform forging is one of the secondary deformation technique applied to conventionally produced powder metallurgy parts in order to achieve near net shape; therefore to find places in structural and heavy duty applications. Present investigation pertains to evaluate the stress–strain and densification behaviour of Fe–0.8%C–1.0%Si–0.4%Cu steel performs during cold upsetting. Secondary cold deformation operations were carried out on the preform of constant initial density and aspect ratio of 86% theoretical and 0.40, respectively. Using 1.0 MN hydraulic press, the incremental loading step of 0.04 MN being applied on the preform under dry and graphite employed friction condition at die contact surfaces up to crack appeared at free surfaces of deforming preform. The experimental results were critically analysed for stresses as a function of strain and densification, further it is extended to analyse work hardening behaviour. As a conclusive, it has been identified that in the process of enhancing densification, the strength and strain is also induced, however the work hardening behaviour was not homogeneously enhanced against induced strain and densification.