SUPERSOLIDUS LIQUID PHASE SINTERING OF AUSTENITIC STAINLESS STEEL- YTTRIA COMPOSITES

摘要

The present study examines the effect of rare-earth oxide addition on austenitic stainless steel during solid-state and supersolidus liquid phase sintering (SLPS). Up to 10 wt.% yttria (Y_2O_3) was added to 316L stainless steel. The compacts were solid-state and supersolidus sintered at Sintering was done at 1250°C and 1400°C, respectively. The sintered samples were characterized for their density, hardness, corrosion and wear resistance. The effect of sintering and yttria addition on the microstructural evolution in supersolidus sintered samples is compared with that obtained by solid-state sintering. The density of stainless steel samples sintered by supersolidus route was higher than the solid-state sintered samples. This results in the SLPS samples having superior corrosion resistance when compared to the solid-state sintered samples. The presence of second phase dispersoids does not appreciably degrade the corrosion resistance of the samples. The Y_2O_3 dispersed samples exhibited better wear resistance when compared to the straight P/M stainless steel both in solid-state as well as supersolidus sintered conditions.