Carburizing Furnace Heat Fan Axis High-temperature Corrosion Of Failure

The heat-resisting alloys are required to be used at higher temperature in many situation, and the hot corrosion is an important factor to decrease their lifetime and to restrict those alloys to further spread their applications. By the means of practical testing in a carbon atmosphere, the hot corrosion of the austenite heat-resisting steel and another heat-resisting alloy, Cr20Ni80 is researched. The fracture topograph, components and the micro-structure of the failed fan shaft, which is made of Cr25Ni20Si2 austenite heat-resisting steel, are analyzed. Furthermore, the failure mechanism is discussed by several methods, i.e. scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and energy dispersive X-ray spectroscopy (EDS). The hot corrosion of the Cr25Ni20Si2 fan shaft in the carbon atmosphere are local ones, mainly composed of grain boundary corrosion and metal powdering, and companied with some pits. The hot corrosion of the Cr20Ni80 fan shaft in the carbon atmosphere are also local ones, mainly composed of sulfuring corrosion, and companied with carbonizing corrosion. The lifetime of the Cr20Ni80 fan shaft is shorter than that of Cr25Ni20Si2 fan shaft.