关键词: N08120镍基合金, 热轧厚板, Z相, 析出规律

Abstract: With regard to the whole production process of N08120 nickel-based thick plate， the precipitation law of material in each process was analyzed by using metallographic microscope， scanning electron microscope and Thermo-Calc software. The results indicate that the main precipitation type in N08120 nickel base alloy thick plate is Z phase， accompanied by dispersed MX precipitation phase， which are distributed in strips along the rolling direction. Besides， σ phase， M₂₃C₆ precipitation and transition state from MX to Z phase are also found in ingots and forging billets during production. The analysis reveals that during the mould casting process， the internal heat dissipation of the ingot is slow， which is beneficial to the transformation of NbN to Z phase， and the ingot surface is found to have σ phase precipitation during the die cooling process when it stays at medium and low temperature for a long time. The forging billet and rolling plate are air-cooled after deformation， the main precipitation phase types are Z phase and MX phase. After solution treatment， the species and distribution of precipitated phases in plate have not changed obviously， indicating that Z phase and MX phase have rapid precipitation rate and high thermal stability.

Key words: N08120 Nickel-based Alloy, Hot-rolled Thick Plate, Z Phase, Precipitation Law