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在设计、搭建的高温高速加速冲蚀试验台上对高参数汽轮机常用的6种喷嘴材料进行了高温抗固体颗粒冲蚀试验研究,并对试验后的材料表面进行了微观分析。研究结果表明:6种喷嘴母材均表现出典型的塑性材料冲蚀特性,最大冲蚀率对应的角度在(24±4)°范围内,速度指数在2.7~3范围,均高于Finnie冲蚀模型中的对应数值。在氧化皮颗粒小角度冲蚀下,喷嘴的冲蚀破坏主要是由颗粒的微切削所致。而在大角度冲蚀下,喷嘴材料表面主要受到粒子的正应力作用而产生严重的凿削和塑性变形。通过对试验结果进行系统分析,文中在Finnie微切削冲蚀模型的基础上建立了适用于工程实际的高参数汽轮机喷嘴材料抗固体颗粒冲蚀预测模型。该研究结果深化了高参数汽轮机喷嘴高温颗粒冲蚀机制,为综合防治叶栅冲蚀破坏和预测喷嘴高效做功寿命提供了参考。
Six kinds of nozzle materials commonly used in high-parameter steam turbines were subjected to high temperature solid particles erosion test on the designed and built high-temperature and high-speed accelerated erosion test bench. The surface of the material after the test was analyzed microscopically. The results show that all the six kinds of nozzle base metals exhibit the typical erosion characteristics of plastic materials. The maximum erosion rate corresponds to an angle within the range of (24 ± 4) ° and the speed index ranges from 2.7 to 3, Erosion model corresponding to the value. At the small angle erosion of the oxide scale particles, the erosion damage of the nozzle is mainly caused by the micro-cutting of the particles. At high angle erosion, the material surface of the nozzle is mainly subjected to the normal stress of the particles, resulting in serious chiseling and plastic deformation. Based on the Finnie micro-cutting erosion model, a solid particle erosion prediction model of high-parameter steam turbine nozzle material is established based on the Finnie micro-cutting erosion model. The results of this study deepen the high-temperature particle erosion mechanism of high-parameter steam turbine nozzles and provide a reference for comprehensive prevention and control of blade erosion damage and prediction of high nozzle service life.