基于数值模拟的镍基高温合金电渣重熔工艺优化

利用MeltFlow软件对镍基高温合金电渣重熔过程进行数值模拟计算,探究了电渣重熔过程中温度场、流场、熔池形貌及微观组织的分布特点,通过工业试验验证模拟的准确性,定量分析熔速对熔炼过程的影响规律,提出了一种改善铸锭凝固质量的工艺优化方法.结果 表明,渣池内的温度相对较高且分布均匀,熔池形貌近似"V"型.铸锭一次枝晶间距...

Optimization of electroslag remelting process of Ni-based superalloys based on numerical simulation

A mathematical model was developed to describe the interaction of multiple physical fields during electroslag remelting ESR process of Ni-based superalloys. The temperature field, flow field, melt pool morphology and microstructure morphology during the remelting process of superalloys were simulated by software MeltFlow. The numerical simulation results were verified based on experimental data. Finally, the influence of melting speed on the melting process was quantitatively analyzed and an optimization method for improving the solidification quality of ingots was proposed. It was shown that the temperature of slag pool was relatively high and uniform, and the melt pool was similar to a "V". The primary dendritic arm spacing of the ingot decreased from the centre to the edge along the radial direction, while the secondary dendritic spacing did not differ significantly. Compared to experimental data, the numerical simulation results were less different from the experimental results, so the model could accurately predict the melt pool morphology and dendrite arm spacing of the electroslag remelting process of Ni-based superalloys. As the melting rate decreased, the depth of molten metal pool decreased, the secondary dendrites arm spacing of the ESR ingot gradually decreased, the macro-segregation of the ingot was improved, and the probability of freckles was gradually reduced. Controlling the melting rate from 0.47 kg/min to 0.45 kg/min was conducive to obtaining ESR ingots of the Ni-based superalloy with good solidification quality.