Impacts of Temperature and KCl on Corrosion Behavior of 12Cr1MoVG and T91 in HCl-Containing Atmosphere

摘要

The corrosion behavior of 12Cr1MoVG and T91 was investigated in a HCl-containing simulated atmosphere. Exposure experiments were divided into two groups to study two key factors, i.e., temperature and KCl, affecting high-temperature corrosion in biomass-fired boiler. One group was conducted at the temperatures of 400, 500 and 600 degrees C. The other was carried out at 500 degrees C with KCl-coated specimens. Corrosion kinetics were plotted on the basis of mass gain. The results showed that, for both alloys tested, the corrosion rates were very temperature dependent and greatly affected by the presence of KCl. The total mass gains of the specimens increased significantly with temperature increase as well as KCl coating. The results also showed that T91 was more corrosion resistant than 12Cr1MoVG under the conditions in this paper. Micro-morphology studies of the corroded specimens were conducted. The results supported the theory that the corrosion process followed an active oxidation mechanism.