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Vol.62, No.2, 81 ~ 94, 2024
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| Title |
| Hot Deformation Behavior of Inconel 718 Alloy Using Regression-based Dynamic Material Model and Applications in Ring Rolling Manufacturing |
| 양선영 Seon Yeong Yang , 박진욱 Jin Wook Park , 윤준석 Jun Seok Yoon , 이광석 Kwang Seok Lee , 이동근 Dong-geun Lee , 신다슬 Da Seul Shin |
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| Abstract |
| Inconel 718 nickel-based alloy is extensively used in the aerospace industry (e.g., gas turbine engine components) because of its excellent corrosion resistance and high mechanical properties at elevated temperatures. However, there is a certain limit to manufacturing the alloy through plastic deformation due to its high deformation resistance and complicated deformation behaviors. In this study, the hot deformation behavior of Inconel 718 alloy was investigated to establish how processing conditions of flow stress-strain, at strain rates from 0.001 to 10 s-1, and temperatures from 850 to 1200℃, affected dynamic recrystallization. The regression-based material model was utilized to calculate the strain-rate sensitivity, and subsequently depict the efficiency of the power dissipation and instability criterion of hot deformation. The processing map and instability criterion predicted by the developed 3rd-order polynomial regression model corresponded with the experimental results and in particular, showed a better prediction for instability regime compared to the existing discrete derivative approach. Predicting the strain-rate sensitivity values on a continuous scale with regression analysis covered the additional instability region of the high strain rate near 10 s-1. The dynamic recrystallization deformation was also characterized by microstructural analysis along with the processing map. Consequently, ring-rolled aviation parts were manufactured with the optimum processing parameters, which conform to the AMS 5663 standard (Aerospace material specifications for Inconel 718).
(Received 6 October, 2023; Accepted 11 November, 2023) |
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| Key Words |
| Inconel 718, hot deformation, model regression, processing map, dynamic recrystallization |
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