Coke formation and metal dusting of electroplated Ni 3Al–CeO 2-based coatings in CO–H 2–H 2O

Abstract

Coke formation and metal dusting of electrodeposited pure, 5 μm CeO 2-dispersed, and 9–15 nm CeCO 2-dispersed Ni 3Al coatings were investigated in CO–H 2–H 2O at 650 °C for a period of 500 h. All Ni 3Al 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 2O 3 scale. CeO 2-dispersed Ni 3Al coatings, especially 9–15 nm CeCO 2-dispersed coatings, exhibited more severe coke formation and metal dusting than the pure Ni 3Al 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 3Al coatings.