INTERNAL OXIDATION OF THE MOST REACTIVE COMPONENT OF TERNARY ALLOYS UNDER LOW OXIDANT PRESSURES
低氧压下三元合金最活泼组元单一内氧化的理论分析

The internal oxidation of the most reactive component C of ternary A-B-C alloys by a single oxidant is examined assuming a gas-phase oxidant pressure below the stability of the oxides of A and B.The precipitation of the most stable oxide leaves behind a matrix of a binary A-B alloy,of which the composition affects the solubility and diffusivity of the oxidant within the internal oxidation zone,herewith,the oxidation kinetics.Approximate relations between these properties are proposed and used to predict the kinetics of internal oxidation of C under the assumption of parabolic rate law.The results obtained for the ternary alloys are compared with the behavior of binary A-C and B-C alloys with the same C content.A new important factor of the ratio of A to B of the bulk ternary alloy is postulated to establish the difference between the internal oxidation in ternary A-B-C alloys and in binary A-C and B-C alloys under a fixed gas-phase oxygen pressure and C content.