A number of experimental nickel base afloys have been evaluated regarding their resistance against high temperature corrosion in waste fnel combustion.
Specimens were prodnced by hot extrnsion of 50 kg ingots and exposed at 450°C and 490°C on cooled testing probes in the superheater section of a municipal solid waste (MSW) incineration plant. The effect on corrosion by different chromium, molybdenum and niobium concentrations were studied in terms of wall thickness rednction dnring test periods of up to 2160 hours. Comparison was made with reference materials such as low alloyed pressure vessel steel (ASME SA213 T12), Alloy 28 (UNS N08028) and Alloy625 (UIW N06625). The results indicated a positive effect in nickel base alloys on corrosion resistance especially of molybdenum but to some extent also of chromium. Nickel, niobium and iron showed no significant effect on corrosion resistance.
Kevwords: hot corrosion, waste incineration, superheaters, probe testing, Alloy 625, experimental afloys