Corrosion behavior of Ni–25Cr–10Fe–3Si–xMo alloys beneath KCl–ZnCl₂ deposits at 650°C: Role of long‐term aging

Abstract

The corrosion behavior of unaged and thermally aged Ni–25Cr–10Fe–3Si–xMo (x = 0, 3 wt%) alloys was studied beneath KCl–ZnCl2 deposits at 650°C. The results indicated that the addition of Mo promoted the formation of a continuous Si‐rich protective layer and improved the corrosion performance of the unaged Ni–25Cr–10Fe–3Si–xMo alloys. The precipitates formed after long‐term aging greatly affect the corrosion resistance of the thermally aged alloys. The M23C6 along the grain boundaries is beneficial to improve corrosion resistance, however, the dispersed Laves phase and Sigma deteriorate corrosion resistance.