EFFECTS OF CERIA COATINGS ON MATERIALS PERFORMANCE OF 430 STEEL IN COAL SYNTHETIC GAS

摘要

Carbon, which is a reaction product of various reactions occurring in syngas at SOFCoperating temperatures, can diffuse into metallic materials and cause carbon-inducedcorrosion (CIC) in the form of carburization or metal dusting. Therefore, The U.S. Departmentof Energy, National Energy Technology Laboratory is investigating susceptibility of 430-basedstainless steel for the SOFC interconnect applications. The 430 stainless steel was modifiedin-house by reducing the amounts of silicon and aluminum. Also, the surfaces of somecoupons were treated with ceria.In this research, the surfaces of low silicon and aluminum 430 stainless steel couponswith and without ceria surface treatment were investigated after exposure to simulated coalsyngas-based fuel at 800℃. The results of X-ray diffraction (XRD) and microscopicinvestigations indicate oxide formation for ceria treated and untreated coupons. Higher carboncontent was detected by the LECO combustion analysis for ceria treated coupons than forbare coupons. Also, the Fe-rich particles formed on the ceria treated coupons. The resultsindicate a different mechanism of carburization for the ceria treated steel than that for theuntreated steel.