METHOD OF HEAT TREATMENT OF ARTICLES MADE FROM HIGH-TEMPERATURE DEFORMABLE PRECIPITATION HARDENING NICKEL-BASED ALLOYS Russian patent published in 2005 - IPC

FIELD: metallurgy; heat treatment of articles made from high-temperature deformable precipitation hardening nickel-based alloys.

SUBSTANCE: proposed method includes hardening and stepped aging; hardening is performed at temperature which is higher than T_c.dis.γ by 30-100°C; holding at this temperature is continued for at least 5 min and is followed by cooling in air; stepped aging is performed at three stages: at first stage heating is performed to temperature which is below temperature T_c.dis.γ by 50-100°C and holding is continued for at least 2 h and is followed by cooling in air; at second stage, heating is performed to temperature 770-860°C and holding at this temperature is continued for at least 5 h and is followed by cooling in air; at third stage heating is performed to temperature of 660-750°C and holding at this temperature is continued for at least 10 h and is followed by cooling in air; T_с.dis.γ is temperature of complete dissolving of γ-phase.

EFFECT: high level of short-term and long-term strength, plasticity, impact viscosity; reduced sensitivity to stress concentrators; enhanced structural stability in welded units; improved weldability.

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