K418高温合金增压器涡轮精密铸造工艺数值模拟研究

Numerical Simulation Study on K418 Superalloy Supercharger Turbine Precision Casting Process

  • 摘要: 该文采用MAGMA铸造仿真软件模拟了K418高温合金增压器涡轮精密铸造工艺,研究了合金液在浇铸过程中的流体温度场、凝固过程中的液相温度场等,然后结合模拟结果试制了增压器涡轮,并对其进行了金相组织分析。结果表明:采用底浇式浇铸系统并将浇注温度设定为1 550 ℃,可以保证合金液具备良好的充型能力;铸件的凝固顺序为:叶片边缘-叶片-叶片轴心-浇冒口-冒口中心,可以保证涡轮零件实现良好成型,并且缩松等缺陷可能出现的位置位于冒口区域;涡轮叶片组织致密,无明显缺陷,叶片位置由柱状晶和细小等轴晶组成,根部及轴心部位为排列整齐的等轴晶。所设计的浇注系统和浇铸温度等工艺合理,可作为实际生产的指导方案。

     

    Abstract: In this paper, the precision casting process of K418 high-temperature alloy turbocharger turbine is simulated by using the MAGMA casting simulation software, then the fluid temperature field during casting and liquid phase temperature field during solidification are studied. Combined with the simulation results, a turbocharger turbine is produced, and the metallographic structure of the turbine is analyzed. The simulation results show that in the designed casting system, the casting temperature is 1 550 ℃, and it ensures a good filling capacity of the alloy liquid. The solidification sequence of castings is as follows: blade edge - blade - blade axis - pouring riser - pouring riser center. This sequence ensures that the turbine parts are well formed, and the possible location of defects such as shrinkage is located in the outlet area. The microstructure of the turbine is dense and without defects. The position of the blade is composed of columnar crystals and fine equiaxed crystals. The root of the blade and the axial center of the turbine are arranged equiaxed crystals. The casting system and casting temperature designed in this paper are reasonable and could be used as guiding scheme for the actual production.

     

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