650 ℃의 10%O2+10%CO2 가스 환경에서 2.25Cr-1Mo강의 산화특성에 미치는 KCl(s)과 K2SO4(s)의 영향

Abstract

In this study, the effects of KCl(s) and K2SO4(s) on the oxidation characteristics of 2.25Cr-1Mo steel wereinvestigated for 500 h in 10O2 + 10CO2 (vol%) gas environment at 650 °C. Oxidation kinetics were characterizedby weight gain, oxide layer thickness, and fitted models for the experiment data were proposed. The fittedmodels presented considerable agreement with the experimental data. The oxide layer was analyzed usingthe scanning electron microscope, optical microscope, and energy dispersive X-ray spectroscopy. The oxidationkinetics of 2.25Cr-1Mo steel with KCl and K2SO4 coatings showed significantly different oxidation kinetics. KCl accelerated the oxidation rate very much and had linear oxidation behavior. In contrast, K2SO4 hadno significant effect, which had parabolic kinetics. The oxide layer was commonly composed of Fe2O3, Fe3O4,and FeCr2O4 spinel. KCl strongly accelerated the oxidation rates of 2.25Cr-1Mo steel in the high-temperatureoxidation environment. Conversely, K2SO4 had little effect on the oxidation rates.