In this project, we conducted chemical and structural analyses of deposits in a water-cooled exhaust pipe to identify the cause of pitting. The main components of the deposits were iron, carbon, oxygen, and calcium, with the presence of calcite, hematite, magnetite, and goethite. Internally, there were soot deposits and minimal crystallization, while the exterior exhibited fully recrystallized goethite. The analysis suggests that hot gas corrosion, driven by sulfur-containing compounds and moist exhaust gases, is the primary cause. Potential solutions include Cr2O3 coatings or plasma-sprayed coatings.