In Europe, a growing demand for heat recovery systems comes from the power plant operators. Heat recovery systems are designed to be operated under acid dewpoint conditions. Only high performance alloys can withstand the corrosive load generated by the precipitation of hot, concentrated and contaminated mineral acids. In a nickel matrix, the right balance of the elements chromium and molybdenum is decisive for the corrosion resistance of such metallic materials. On the basis of laboratory and field investigations, the corrosion behaviour of new and established alloys is described in this paper.
Keywords: Power plants; flue gas desulphurisation, FGD, heat recovery systems, heat exchangers, dewpoint, sulphunc acid, suiphur dioxide, sulphur trioxide, chlorides, nickel alloys, Alloy 31, Alloy C-276, Alloy 59, Alloy B-4, Alloy B-10