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

Coke formation and metal dusting of electrodeposited pure, 5 μm CeO2-dispersed, and 9–15 nm CeCO2-dispersed Ni3Al coatings were investigated in CO–H2–H2O at 650 °C for a period of 500 h. All Ni3Al 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 Al2O3 scale. CeO2-dispersed Ni3Al coatings, especially 9–15 nm CeCO2-dispersed coatings, exhibited more severe coke formation and metal dusting than the pure Ni3Al coating. The detrimental effect of CeO2 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 Ni3Al coatings.