Improved LBE corrosion resistance of the FeCrAl coating by the addition of trace Si element

Three kinds of FeCrAlSi coatings with different Si contents were prepared by the magnetron sputtering method, and the LBE corrosion resistance was investigated at 500 °C, 550 °C, and 600 °C for 1000 h. The results showed that the corroded coatings present a shiny surface (circle morphology). The increase of Si content promotes the thinning of the total oxide scale and thickening of the Al2O3 layer. The Si-rich layer appeared between the FeAl2O4 and the Fe(Cr,Al)2O4 spinel layers. The corrosion mechanism is discussed in detail, and a corrosion model based on the TEM analysis of the coatings corroded at 600 °C is proposed.