In order to improve the castings quality of nickel-based superalloy in investment casting process, especially to reduce the shrinkage porosity, the processing parameters were optimized by numerical simulation and Taguchi method. The effects of processing parameters, such as pouring temperature, pouring time and mold shell preheating temperature, on the shrinkage porosity in the turbine nozzle investment castings prepared by K477 nickel-based superalloy were investigated. The results show that the effects of the mold shell preheating temperature, pouring temperature and pouring time are main influencing factors in turn, which are verified by the evaluation of signal-to-noise ratio and the analysis of variance. Further, based on the processing optimization, a K477 alloy turbine nozzle without shrinkage porosity was prepared with the optimized parameters: pouring temperature of 1450∘C, mold shell preheating temperature of 1050∘C and pouring time of 14 s, respectively.

中文翻译：

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田口法降低镍基高温合金铸件缩松的熔模铸造参数优化

为了提高熔模铸造过程中镍基高温合金的铸件质量，特别是降低缩松率，采用数值模拟和田口法对工艺参数进行了优化。研究了浇注温度、浇注时间、型壳预热温度等工艺参数对K477镍基高温合金涡轮喷嘴熔模铸件缩松率的影响。结果表明，模壳预热温度、浇注温度和浇注时间依次是主要影响因素，并通过信噪比评价和方差分析验证了这一点。此外，基于处理优化，1450∘C，模壳预热温度为1050∘C和浇注时间分别为 14 秒。