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Acta Aeronautica et Astronautica Sinica ›› 2026, Vol. 47 ›› Issue (2): 431854.doi: 10.7527/S1000-6893.2025.31854

• Material Engineering and Mechanical Manufacturing • Previous Articles     Next Articles

Process optimization and control of vacuum arc remelting for extra large-sized GH4169 ingot

Shu LI, Hengnian ZHANG, He JIANG(), Zhihao YAO, Jianxin DONG   

  1. School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China
  • Received:2025-02-10 Revised:2025-03-10 Accepted:2025-05-23 Online:2025-06-10 Published:2025-06-06
  • Contact: He JIANG E-mail:jianghe17@sina.cn
  • Supported by:
    National Science and Technology Major Project of China(2019-VI-0021-0137)

Abstract:

To investigate the vacuum consumable remelting process of extra large-size GH4169 alloys and improve ingot quality, an optimization method for the vacuum consumable melting process of large-sized GH4169 ingots with a diameter of ∅1 000 mm was developed based on the MeltFlow software, which has been extensively validated in industrial applications. The study explored the evolution of melten pool morphology, solidification characteristics, inclusion distribution, and macro-element distribution during the remelting process. Additionally, the effects of melting rate, cooling condition, and hot topping process on segregation probability, Secondary Dendrite Arm Spacing (SDAS), element distribution, shrinkage cavity formation, and macro-element distribution were analyzed. After 1 055 min of vacuum consumable remelting, the molten pool gradually stabilized, with a maximum depth and mushy zone width of 316 mm and 37 mm, respectively. The overall molten pool exhibited a “U” morphology. During stable remelting, the simulated cooling rates of the ingot surface and center were 0.390 K/s and 0.025 K/s, respectively. The primary dendrite arm spacings of the ingot surface and center were 205 μm and 512 μm, while the secondary dendrite arm spacings were 60 μm and 174 μm, respectively. Overall, elements such as Nb, Mo, Ti, and Al were evenly distributed throughout the ingot. For ∅1 000 mm large-scale GH4169 ingot, when the melting rate is controlled within the range of 3-8 kg/min and water cooling or helium cooling is employed, an increase in melting rate and cooling rate will reduce the secondary dendrite arm spacing. Variations in melting rate and cooling conditions may influence the morphology of Ra, but all Ra remain below 1, resulting in a relatively low probability of freckle formation. The SDAS decreased with increasing melting rate and cooling speed, while the segregation probability decreased with increasing melting rate and decreasing cooling rate. Among various hot topping processes, a process with equal durations of the rapid current reduction phase, slow feeding phase, and low-current insulation phase reduced the SDAS and segregation probability in the ingot center.

Key words: GH4169, vacuum consumable remelting, molten pool, dendrite arm spacing, freckle

CLC Number: