Sintering response of austenitic (316L) and ferritic (434L) stainless steel consolidated in conventional and microwave furnaces

This study compares the effect of heating mode on the densification, microstructure, strength and hardness of austenitic and ferritic stainless steel. The compacts were sintered in a radiatively heated (conventional) and a 2.45 GHz microwave furnace. Both 316L and 434L compacts couple with microwaves and heat up to the sintering temperature rapidly (∼45 °C/min). The overall processing time was reduced by about 90% through microwave sintering. While the microwave sintered compacts exhibit a finer microstructure, there is no corresponding improvement in densification and mechanical properties. This has been correlated with elongated and irregular pore structure.