Coke formation and metal dusting of electroplated Ni3Al–CeO2-based coatings in CO–H2–H2O

Abstract Coke formation and metal dusting of electrodeposited pure, 5 μm CeO 2 -dispersed, and 9–15 nm CeCO 2 -dispersed Ni 3 Al coatings were investigated in CO–H 2 –H 2 O at 650 °C for a period of 500 h. All Ni 3 Al coatings showed the inferior long-term resistance to coke formation and metal dusting to the Fe–Ni–Cr alloy due to failure to form a continuous Al 2 O 3 scale. CeO 2 -dispersed Ni 3 Al coatings, especially 9–15 nm CeCO 2 -dispersed coatings, exhibited more severe coke formation and metal dusting than the pure Ni 3 Al coating. The detrimental effect of CeO 2 is believed to be caused by the enhanced formation of NiO/Ni crystals on the coating surfaces or at the grain boundaries, which catalysed the carbon deposition and promoted the carbon attack on Ni 3 Al coatings.