湿潤炭酸ガス中における0.4 wt%Ca-Be合金の酸化

Abstract

0.4 wt%Ca-Be alloy was oxidized in moist CO2 (water vapour pressure, 14 to 25 mmHg) over the temperature range 700°∼800°C. Discontinuity of the weight gain vs. time curves suggests that the oxidation of 0.4 wt%Ca-Be alloy occurs through three reaction stages. The rates of oxidation at the initial two reaction stages were parabolic.The effect of water vapour pressure on the parabolic rate constants as(This article is not displayable. Please see full text pdf.) where kp is the parabolic rate constant, kp° the parabolic rate constant in dry CO2, a constant, ΔH the activation energy for the parabolic oxidation.Pressure of moisture effected the activation energy of the reaction suggesting that the rate controlling step is different from that for dry CO2. Increase in the partial pressure of water vapour causes a change in the entropy term in a manner indicated in the above equation.The third stage follows a linear rate law resulting in a rapid disintegration.