Metal Dusting Behaviour of Fe-Cr and Fe-Cr-Ni Alloys under Blast Furnace Operating Condition

Abstract

Metal dusting behaviours of Fe-(10, 20, 25)Cr, Fe-20Cr-(20, 33)Ni, Fe-25Cr-20Ni (wt.%) in a Ar-33CO-7H2-7CO2-2H2O (vol.%) gas at 550℃ and 650℃ were investigated in simulating a blast furnace operating condition. Severe metal dusting and coke deposition were observed at 550℃, while no significant dusting but internal oxidation and carburization were observed at 650℃. Higher Cr and Ni contents in the alloy lowered kinetics of metal dusting at 550℃ and of carburization at both temperatures. In particular, Fe-25Cr was the only alloy exhibiting no significant metal dusting at 550℃. Increasing Cr concentration also reduced oxidation kinetics at both temperatures. Austenitic alloys were more susceptible to metal dusting and coke deposition than ferritic alloys with the same Cr content at 550℃. At 650℃, however, ferritic alloys experienced higher extents of carburization and oxidation than austenitic alloys with the same Cr concentration.