650 °C 의 SO 2 가스 환경 하에서 T22와 T92 강의 고온 부식특성

In this study, the corrosion characteristics of T22 and T92 steel were investigated in 6O 2 + 16CO 2 + 2SO 2 gas environment at 650 °C. Corrosion characteristics were characterized by weight gain, oxide layer thickness, scanning electron microscope, optical microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction. T22 and T92 steel tended to stagnate oxide layer growth over time. Oxidation kinetics were analyzed using the data of oxide layer thickness, and a regression model was presented. The regression model was significantly acceptable. The corrosion rate between the two steels through the regression model showed significant difference. The T92 steel was approximately twice as large as the time exponent and showed very good corrosion resistance compared to the T22 steel. In both steels, the oxide layer mainly formed a Fe-rich oxide layer composed of hematite (Fe 2 O 3 ), magnetite (Fe 3 O 4 ), and spinel (FeCr 2 O 4 ). Sulfide segregation occurred in the oxide layer due to SO 2 gas. However, the locations of segregation for the T22 and T92 steel were different.