Abstract
The precipitation and dissolution behavior of hot-extruded alloy 718 was investigated during isothermal treatment at temperatures from 600°C up to 1150°C at different times from 0.3h to 72h. Analysis was conducted using hardness measurement and an electron microscope. It was observed that the γ/γ′ phases were precipitated further during isothermal exposure at 600°C-700°C. When the isothermal treatment was carried out at 800°C, the δ phase was precipitated at the expense of the γ′ phase, which resulted in a slight decrease of hardness with increasing holding time. Above exposure temperature of 900°C, a rapid decrease in hardness occurred within the holding time of 0.3h, resulting from the dissolution of the γ phase and a sharp decrease in the amount of the γ′ phase. Rapid grain growth also affected the decrease in hardness above 900°C.
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Geng, L., Na, YS. & Park, NK. Precipitation behavior of hot-extruded alloy 718 during isothermal treatment. Metals and Materials 5, 389–393 (1999). https://doi.org/10.1007/BF03187763
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DOI: https://doi.org/10.1007/BF03187763