The Effects of Mo Addition on the Structure of Scales Formed in High Si Steel at 1150°C

Abstract

High Si steels (base steel and with addition of 0.1, 0.3, 0.5mass% Mo) were oxidized in a N2-3%O2-20%H2O atmosphere at 1150oC for 0.3-10.8ks. The oxidation kinetics showed that base steel has the highest weight gain. In contrast, 0.5Mo has the lowest weight gain. From SEM results, the scale thickness decreased as Mo content increased. Distribution of alloying elements showed that Mo is enriched in internal oxidation zone (IOZ) and played a role in slowing the outward diffusion of Fe, thus, producing a thinner Fe oxide scale and lower weight gain.