2022 Volume 62 Issue 12 Pages 2573-2577
A new carbonizing and pulverizing process of woody biomass has been proposed, which utilizes sensible heat of industrial flue gas using a heat storage material (HSM). In the present study, Fe–Mn–C alloy was examined as a candidate of HSM, however, it has rather poor high-temperature oxidation resistance and therefore its aluminizing treatment was attempted to solve this problem. The Al-rich layer growth and alumina formation behaviors on the Fe–Mn–C alloy during aluminizing treatment using the pack cementation method were studied. Alloy samples were aluminized at 700–900°C for 3–12 h. Change in the sample weight was measured using a TG at 1000°C for 24 h in air.
FeAl layer formed in the early stage of aluminizing, followed by Fe2Al5 layer formation. Acicular FeAl2 phase precipitates in the FeAl layer. The sample aluminized at 700°C for 12 h does not have sufficient oxidation resistance, whereas ones aluminized at 800°C for 12 h and 900°C for 3–12 h show superior oxidation resistance. Continuous Al2O3 layer is formed due to presence of FeAl2 or Fe2Al5 in Al-rich layer.
