Influence of temperature on the forming limit diagrams of sintered P/M preforms of steel

The current paper deals with the generation of formability limit diagrams (FLD) for sintered preforms of steel from room to warm working temperatures. Steel compacts of different resident densities have been prepared by applying recommended pressures. Stage wise upsetting has been carried out to obtain the densification curves from room temperature (27 °C) to 600 °C in steps of 100 °C to explore the possibility of in situ sintering. Compression tests were performed and the critical transition densities vide formability limit diagrams were found to be 6.28 g cm−3 at room temperature, 6.21 g cm−3 at 100 °C, 6.08 g cm−3 at 200 °C, 5.95 g cm−3 at 300 °C, 5.72 g cm−3at 400 °C and 5.5 g cm−3 at 500 °C. The decreasing trend in critical transition density addresses the energy conservation and cost effectiveness during secondary processing of sintered preforms of steel.