High temperature corrosion of metallic materials in coal fired power plant boilers

The aim of this work was to perform high temperature tests in steam conditions at 700‒800°C for 3000 hours. In this work seven alloys were studied: Cr rich austenitic steels 309S, 310S, HR3C, and two solid-solution strengthened Ni based alloys; Haynes^® 230^®, 617 alloy and two (γ’) gamma-prime strengthened Ni based alloys; 263 and Haynes^® 282^®. The obtained results suggest that the exposed materials show high corrosion resistance under steam oxidation conditions where predominantly Cr₂O₃ and MnCr₂O₄ compounds developed. The materials showed no chromia evaporation process and no exfoliation of the external oxide scale. However, two (γ’) gamma-prime strengthened Ni based alloys showed a high degree of internal oxidation that increased with temperature.

Download 6.74 MB >>