Microstructure and high-temperature oxidation behavior of wire-arc sprayed Fe-based coatings

• Fe–xCr cored wires were used to produce coatings by the wire-arc spraying process.
• High-temperature oxidation behavior was investigated by thermogravimetric test.
• Final weight gains and thickness of oxide scales were connected with Cr contents.
• The compositions of oxide scales were connected with Cr contents of the coatings.

A series of Fe–xCr cored wires (x = 15, 20, 25, 30, 35 and 40% in weight) were used to produce protective coatings for components used in high-temperature environments by wire-arc spraying. The microstructure, morphology and high-temperature oxidation behavior of the Fe–xCr coatings were investigated. The Fe–xCr coatings presented a homogeneous structure with thin oxide inclusions and low porosity. Thermogravimetric analysis was used to evaluate the high-temperature oxidation behavior of the coatings at a temperature of 650 °C under cyclic oxidation conditions. The results showed that all the Fe–xCr coatings exhibited significantly lower weight gain than the uncoated substrate. As Cr content of the coatings increased, the thickness of oxide scales decreased and oxidation resistance improved.