An Exploration of the Effect of Temperature on Different Alloys in a Supercritical Carbon Dioxide Environment

[摘要] (cont.) The chromium content for the AUSS 316L was also the lowest, which most likely contributed to the high oxidation rates. The tests conducted at 750 °C and 12.5 MPa showed the highest weight gain rates for the nickel based alloys, which was expected as the corrosion rate should follow an Arrhenius trend. The effect of pressure was small compared to the effect of temperature as a 43% reduction in pressure and a 5% increase in temperature produced significantly higher corrosion rates in the nickel based alloys. The AUSS 316L, behaved counter-intuitively as the highest temperature experiment, 750 °C and 12.5 MPa, had the lowest weight gain rate. This behavior may be explained by the increase in temperature, which caused an increase in the diffusion rate within the alloy. This facilitated a faster growth rate of an inner ;;healing;; layer composed of chromium rich oxide, which may have restricted the outward diffusion of cations and inward diffusion of anions.

[发布机构] Massachusetts Institute of Technology