Oxidation resistance of sintered stainless steels: effect of yttria additions

The porosity of sintered stainless steels modifies their oxidation behavior, as compared to that of wrought stainless steels. This work studies the oxidation behavior of three sintered stainless steels: one ferritic (AISI 434L) and two austenitic (AISI 316L and 304L). 304L with yttria additions is also been studied to explore the possibility of reducing the oxidation rate of austenitic stainless steels by using this reactive element. The results demonstrate the influence of the formation of NiFe₂O₄ on the high-temperature behavior of sintered austenitic stainless steels and the effectiveness of yttria additions in increasing the oxidation resistance at 800 °C.