Evaluation of Metal Dusting Behavior in Reformer Tube Made of HP–Nb Alloy on the Outer Surfaces

摘要

Abstract The metal dusting behavior of Iron–Chromium–Nickel heat resistant HP–Nb steel specimen was investigated at the outer surfaces while the methane gas was passed inside the hole of the specimen. After an exposure of 130?h in a flowing methane (CH4) gas at 680?°C, different dispersed corrosion products were formed on the outer surface of the specimen near the hole. Conventional metallography and scanning electron microscopy were used to identify the microstructure of the reaction products. Energy dispersive X-ray spectroscopy was used for microchemical analysis. The phases produced on the surface were identified by X-ray diffraction. Some of reaction products found as surface deposits on the outer surfaces of specimen near the hole contained Fe and Cr carbides, Fe, Cr and Ni oxides, scale of Ni, Fe particles and free C. Results revealed that carbon nano-filaments materials could be formed during disintegration of heat resistant HP–Nb steel under metal dusting environment.]]>