Alloy B-10 is a Ni-Mo-Cr alloy, recently developed for highly acidic but oxygen-deficient environments in the chemical process and environmental protection industries. The new nickel-based alloy with nominally (wt. %) 62 Ni, 24 MO, 8 Cr and 6 Fe, exhibits excellent corrosion resistance in intermediate concentrations of sulfuric acid, as well as in hydrochloric acid, even with additions of small amounts of oxidizing agents. In a simulated Flue Gas Desulfurization (FGD) environment of
sulfuric acid of pH 1 with additions of 7 % chloride and 0.01 % fluoride, and also containing 15 % gypsum the new alloy demonstrated high crevice corrosion resistance at 100°C, whereas a common Ni-Cr-Mo alloy of the C-type suffers crevice corrosion under the same conditions. This new alloy can easily be welded without tiller or using matching filler. Good practical experience has been gained with Alloy B-10 in a district heating power station as a tube sheet and bottom wall liner for a glass tube heat exchanger working at 130°C with condensing 70 % sulfuric acid. Keywords: Alloy B- 10, sulfuric acid, hydrochloric acid, crevice corrosion, heat exchangers economizers, flue gas desulfurization, fgd, gas reheaters