高强不锈钢离心轮浇冒口的设计与计算

Design and calculation of casting head for high strength stainless steel centrifugal impeller

离心轮为重型运载液氧煤油发动机涡轮泵中的关键零件,结构复杂,材质为高强不锈钢S-04。工作时高速旋转,叶片型面与燃料直接接触,承受载荷大,对其尺寸精度和内部质量要求高,采用熔模铸造方法生产。为防止铸件热节部位出现缩孔、缩松缺陷,需要合理设计浇冒系统,保证铸件质量。采用模数法对离心轮铸件冒口进行设计与计算,并对冒口补缩能力进行校核,保证冒口有足够的金属液补缩铸件。经过实际生产验证,离心轮冒口实用可靠,铸件的热节部位得到了有效补缩,成功浇注出了高质量的离心轮铸件。离心轮工艺方案合理、有效,验证了用模数法设计与计算高强不锈钢离心轮浇冒口的准确性。

As the key part of LOX/kerosene engine turbopump for heavy launch vehicles, the centrifugal impeller is made of high strength stainless steel S-04 with complicated structure. When centrifugal impeller rotates at high speed, blade surfaces contact directly with the fuel, bearing high loads, which results in the high requirements of its dimension precision and internal quality.Therefore, investment casting was chosen for centrifugal impeller production. In order to prevent shrinkage cavity and porosity at casting hotspots, the casting head needs to be properly designed to guarantee casting quality. The centrifugal impeller casting head was designed and calculated via modulus method to check the casting head feeding capacity, ensuring enough molten metal to feed the casting. The produced centrifugal impeller casting was of high quality with practical and reliable casting head and effective feeding of casting hotspots. It's proved that the process plan for centrifugal impeller is proper and effective. The design and calculation accuracy of casting head for high strength stainless steel centrifugal impeller was verified with modulus method.