Effect of copper and VCN additions on sintering of low alloy steel

In the present study, copper and vanadium carbonitride (VCN) were added to low alloy P/M steel and their effects on the densification behaviour and mechanical properties were studied. The effect of heat treatment was also studied. All the sinterings were carried out at 1120°C for 1 h in hydrogen. For heat treatment, the samples were austenitised at 1000°C for 10 min and then oil quenched to room temperature. The increase in carbon level in steel from 0.3 to 0.5% resulted in better densification and better mechanical properties. The results showed that, although copper addition resulted in poor densification, it improved mechanical properties of the steel. Further improvement was observed after heat treatment. The best results were observed for 10% copper–0% VCN composition. VCN addition in straight steels did not help either in densification or in improving mechanical properties. But when added simultaneously with copper, it affected the densification behaviour of the steel.