K488合金大尺寸涡轮叶片精铸工艺研究

大尺寸涡轮叶片是重型燃气轮机的关键核心部件，采用铸造高温合金K488无余量精密铸造而成，该叶片结构复杂，叶身尺寸大，壁厚薄，尺寸精度高，冶金技术标准要求严格，铸造工艺难度很大。设计采用了蜡模二次成型、反变形技术、顶注一侧注复合浇注系统的优化，解决了铸造过程中产生的疏松、裂纹、变形等缺陷，研制出了合格的大尺寸涡轮叶片。

Study on Investment Casting of Large-size Turbine Blade of K488 Alloy

The large dimension turbine blade is one of the most important parts in gas turbine. It was made of K488 super-alloy through investment casting process. Because of complicated structure, thin wall-thickness, large-dimen- sion, close-tolerance and strict requirements of the metallurgical quality, it is difficult to manufacture turbine blade. We have used some methods in the manufacture of the turbine blade to eliminate the osteo-porosis, crack, deforma- tion and other defects formed in casting process, such as post forming of wax pattern, reversing methodology of ad- justing waxen mould and optimization of the top-side pouring compound casting system. The qualified large turbine blade was prepared by using the above methods successfully.