Ni­20Cr­18W高温合金近液相线熔体处理温度场模拟及参数优化

摘要

采用电磁场近液相线处理工艺对Ni­Cr­W高温合金熔体进行处理，然后浇铸，可获得整体均匀细小等轴晶铸锭。建立不同质量Ni­20Cr­18W高温合金熔体电磁场近液相线熔体处理温度场有限元模型，分析电流频率和加热功率等感应加热工艺参数及合金质量对熔体温度场分布的影响。给出了一定质量的合金熔体整体均匀保温在液相线附近时所对应的最优工艺参数，得到了熔体质量与对应的最优加热功率间的经验关系式。最优电流频率为200 Hz。研究结果可为优化高温合金近液相线熔体处理工艺参数提供依据。%When the Ni­Cr­W superalloy melt was held at near liquidus under electromagnetic field and poured into ingot molds, some ingots with uniform fine equiaxed grains can be obtained. The finite element models of temperature field about different masses of Ni­20Cr­18W superalloy melts treated by induction electromagnetic field were established. The effects of the induction melting process parameters such as current frequency, heating power and the mass of the superalloy melt on the distribution of melt temperature field were investigated. The optimal parameters for holding a certain mass of superalloy melt at near liquidus were obtained. An empirical formula of relationship between the mass of superalloys and optimal heating power was established. The optimal current frequency is 200 Hz. The research results provide a useful support for optimizing the induction melting process parameters for near liquidus melt treatment.