Effect of Ni–Al Coating with and without Re Modification on Coking and Metal Dusting of Fe–Cr–Ni Alloy under Cyclic Condition at 600 °C

Ni–Al coatings with and without Rhenium (Re) modification were prepared using electroplating and packing cementation methods on the matrix of Fe–Cr–Ni alloy. Corrosion behaviours of the matrix alloy and two coated samples were investigated in 30CO–64H 2 –6H 2 O gas mixture under thermal cycling condition at 600 °C. All coated samples showed significantly improved corrosion performance. Re addition was ineffective in controlling the surface coking and metal dusting of Ni–Al coating but enhanced the thermal fatigue resistance to thermal cycling. The corrosion mechanism of Ni–Al coating exposed to metal dusting environment under thermal cycling condition and the effect of Re were discussed.