Oxidation and corrosion protection of ZG12Cr9Mo1Co1NiVNbNB (CB2) ferritic stainless steel by inorganic composite coatings at 650 °C

•Water vapor accelerates greatly the oxidation and corrosion of CB2 steel at 650 °C.•An inorganic composite coating was easily prepared by air spraying process.•The coatings improve both of the oxidation and corrosion resistance at 650 °C.•A thin continuous Cr-rich oxide scale formed beneath the coatings.