Y型管作为航天器燃料的输送管道对其使用寿命极其关键。 本文通过三维造型软件对Y型管进行几何建 模和结构分析，其整体壁厚较薄，3个法兰及凸台位置较厚，存在充型困难，易产生冷隔等铸造缺陷。采用ProCAST模拟 软件对熔模铸造工艺下Y型管进行数值模拟，设置不同的浇注温度和模壳温度，研究对比不同工艺下铸件的冶金质量， 选择最优工艺参数，进而提高Y型管的使用寿命。模拟结果表明，在浇注温度1650℃和模壳温度350℃时，在3%判比 下，铸件疏松体积最小，为1.42cm3，得到铸件的冶金质量最优，随后对该工艺参数方案进行了实验验证。经DR验证，得 到满足相关技术协议的规定的铸件，实验与模拟结果一致，验证了模拟结果的可行性和准确性。

Y-shaped tubes are key to the service life of spacecraft fuel delivery pipelines. Three-dimensional modelling software was used to conduct geometric modelling and structural analysis of the Y-shaped tube, of which the overall wall thickness was thin, and the three flanges and convex position were thick, leading to difficulty in filling the mold and the tendency to form cold shuts and other casting defects. The ProCAST simulation software was used to numerically simulate the Y-shaped tube during the investment casting process. By setting different pouring temperatures and mold shell temperatures, the metallurgical quality of castings under different process parameter schemes was studied and compared. The optimal process parameter scheme was selected to further improve the service life of the Y-shaped tube. The simulation results show that when the pouring temperature is 1 650 ℃ and the mold shell temperature is 350 ℃, the porosity of the casting is the smallest (1.42 cm3) at a 3% ratio, and the metallurgical quality of the casting is the best. The experimental verification of the process parameter scheme was then carried out. Through DR verification, a casting meeting the requirements of the relevant technical agreement is obtained, and the experimental results are consistent with the simulation results, which verifies the feasibility and accuracy of the simulation results.