Study on preparation and properties of CoCrWSi coatings for high parameter steam turbine components

高参数汽轮机部件CoCrWSi系涂层制备及性能研究 Study on preparation and properties of CoCrWSi coatings for high parameter steam turbine components 曹晓英 CAO Xiaoying 1 first-author 王伟 WANG Wei 1 张建普 ZHANG Jianpu 1 东方电气集团东方汽轮机有限公司长寿命高温材料国家重点实验室 东方电气集团东方汽轮机有限公司长寿命高温材料国家重点实验室 Dong Fang Electric Corporation,Dong Fang Turbine Co.,Ltd.,State Key Laboratory of Long-Life High Temperature Mate-rials Dong Fang Electric Corporation,Dong Fang Turbine Co.,Ltd.,State Key Laboratory of Long-Life High Temperature Mate-rials 采用超音速火焰喷涂工艺制备Co Cr WSi系高温抗氧化涂层,并对喷涂态涂层金相组织、显微硬度、结合强度、开裂韧性等性能进行分析。通过长时静态氧化、热震试验考核涂层高温抗氧化性能,采用扫描电镜(SEM)分析了涂层截面形貌及化学成分变化,探讨了抗氧化涂层的氧化过程与防护原理。试验结果表明:Co Cr WSi系抗氧化涂层均匀致密,孔隙率小于1%,显微硬度达543～705 HV0.3,结合强度平均值达81.75 MPa。在200 h高温静态氧化和热震试验条件下,涂层仅有轻微氧化,涂层与基体无分离;氧化物由沿晶粒表面向晶粒内部逐渐包覆氧化,对基体表面起到了有效的防护作用,为630℃及更高温度等级汽轮机部件高温抗氧化防护提供了新的解决方案。 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. 汽轮机 超音速火焰喷涂 抗高温氧化 涂层 热震 steam turbine high velocity oxygen fuel spraying high temperature anti-oxidation coating thermal shock TM621;TG174.4 2022-03-08 1 51