Effect of solution treatment on the hot workability of electroslag remelted Ni?Cr?Mo alloy

The effect of solution treatment on the hot workability of electroslag remelted Ni−Cr−Mo alloy was evaluated. Tensile tests were performed in the temperature range of 950 to 1200°C at a strain rate of 6.1/sec. The hot workability of this alloy appeared to be intimately dependent on the amount of precipitates that were identified as the P phase. A solution treatment at 1250°C for 2 hours induced a considerable dissolution of the precipitates. It resulted in a significant improvement in the hot workability (from 40% to 70% in RA value), giving the deformation mechanism for grain boundary sliding at below 1000°C and dynamic recrystallization at above 1100°C. The hot ductility drop at around 1050°C could be attributed to the precipitates reprecipitated especially at the grain boundary before deformation.