Effect of temperature on coal ash hot corrosion resistance of Inconel 740 superalloy

Coal ash hot corrosion behavior of Inconel 740 superalloy was studied at 700-800 °C in a synthetic coal-fired boiler environment using our high temperature electrochemical sensor. The results of electrochemical noise analysis show good correlations with those from a weight loss test. Characteristic potential noise patterns correspond with the predominant stages in the corrosion process. While, characteristic current noise patterns indicate the extent of the corrosion. The data show that corrosion resistance of the alloy was significantly reduced at 750 °C and the highest tendency of TiS formation in the internal sulfidation stage led to accelerated intergranular and intragranular corrosion.