The Mechanism in High Temperature Corrosion in Municipal Incinerators

Chemical analyses, electron microprobe surveys, and X-ray diffraction examinations of deposits and corroded metal surfaces from corrosion probes exposed in operating municipal incinerators have helped explain the attack observed. It is suggested that the corrosive gases, SO2, SO3, HCl, and Cl2 are of great importance. In addition, low melting chlorine and sulfur-containing salts contribute to the corrosion. The reactions of chlorine with steel are important in the temperature range 204 to 316 C (400 to 600 F) and both HCl and Cl2 cause corrosion at higher temperatures. The reactions of sulfur-containing compounds can cause corrosion over a wide range of temperature.