Co Cr WSi high-temperature anti-oxidation coatings were prepared by high velocity oxygen fuel spraying technology

and the microstructures

micro-hardness

bonding strength and cracking toughness of coatings were analyzed. The long-term static oxidation and thermal shock tests were used to evaluate the high-temperature oxidation resistance of the coatings. Scanning electron microscopy（SEM） was used to analyze the changes of coating section morphology and chemical composition. The oxidation process and protection principle of anti-oxidation coating were discussed. The test results show that Co Cr WSi anti-oxidation coating is uniform and dense

porosity is less than 1%

microhardness is 543 ～743 HV0.3

and the average bonding strength is 81.75 MPa. Under the 200 h high temperature static oxidation and thermal shock conditions

the coating is only slightly oxidized

the coating and the substrate are not separated;the oxide is gradually coated and oxidized from the grain surface to the inside of the grain

and the surface of the substrate has been effectively protected

and new solu-tions have been provided for high-temperature anti-oxidation protection of steam turbine components at 630 ℃ and higher temperature classes.