Influence of sinter-cooling rate on the mechanical properties of powder metallurgy austenitic, ferritic, and duplex stainless steels sintered in vacuum

Austenitic, ferritic and duplex stainless steels obtained through powder metallurgy technology were sintered in vacuum. Powders were compacted at 650 or 750 MPa and sintered in vacuum with two sinter-cooling rates (furnace- and water-cooling). Mechanical properties, using tensile testing and hardness measurements were evaluated. A full microstructural study of the three types of stainless steels was performed. The mechanical behavior was a function of the sinter-cooling rate and the chemical composition. Duplex stainless steel showed the best mechanical behavior. The use of high compaction pressure and water-cooling process promoted the best mechanical results for all compositions.