Objective is to determine and describe the hot corrosion mechanism in MCFC bipolar sheet materials and current collectors and to provide a corrosion model to predict hot corrosion behavior of metals and alloys in the fuel cell environment. Tasks to be performed in accomplishing the objective are (1) to determine the influence of electrolyte composition, amount of electrolyte, gas composition (including the presence of sulfur impurities), composition of the alloy, electrode potential and thermal cycling on the mechanisms of corrosion of bipolar sheet, and current collector materials, As part of the above, the morphological development of oxide scales and adherence of the scale to the substrate shall be determined; (2) to create a corrosion model based on the data obtained; and (3) to recommend bipolar sheet and current collector materials.