Ni基合金のミクロ偏析観察と凝固シミュレーション

抄録

Solidification structure of an alloy of grade Hastelloy G-2 was investigated by differential scanning calorimetry and electron probe microanalyzer. Small amount of Cr and Mo-enriched phase was observed at the final solidification region. Furthermore, the numerical simulation of solidification behavior of this alloy was conducted using the thermodynamic models such as the Scheil-Guillver model and the Partial Equilibrium model, and the Multi-Phase-Field (MPF) method. The simulation results of the MPF method were in good agreement with the experimental results. And the Cr and Mo-enriched phase formed at the final solidification region was predicted as the σ phase from the results of simulation. The MPF method is valuable tool to investigate the microsegregation and phase transformation during the solidification of the Ni-base alloys.