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Vol.60, No.12, 892 ~ 902, 2022
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| Title |
| Effect of Initial Microstructure on the High-Temperature Formability of STS 321 Alloy Using a Dynamic Material Model |
| 조평석 Pyeong-Seok Jo , 이재관 Jae-Gwan Lee , 황효운 Hyo-Woon Hwang , 이용재 Yong-Jae Lee , 이동근 Dong-Geun Lee |
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| Abstract |
| General austenitic stainless steel has a problem with intergranular corrosion due to volatilizing chromium, which forms chromium carbide in a high temperature environment. By adding titanium as an alloying element, STS 321 stainless steel has excellent creep resistance and intergranular corrosion resistance at high temperatures, because the formation of chromium carbide is suppressed. It is important to find the optimal process conditions for STS 321 stainless steel used in the aerospace field, because high temperature processing is mainly applied, and defects or inhomogeneity of materials that occur during high temperature processing lowers the yield of products. In this study, to investigate the effect of the initial microstructure on the high-temperature deformation behavior of STS 321 stainless steel, a high-temperature compression test was performed on two types of STS321 alloys with different initial microstructures. The temperature range was set at 50°C intervals from 800°C to 1100°C, and the strain rate was set at 10-1/sec intervals from 1 × 100/ sec to 1 × 10-3/sec. Based on the experimental results, the thermal activation energy, which differed depending on differences in the initial microstructure, was calculated. In addition, by deriving flow stress and processing maps, the difference in energy dissipation efficiency depending on temperature and strain rate was explained, along with the initial microstructure and high-temperature deformation mechanism.
(Received 11 August, 2022; Accepted 8 September, 2022) |
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| Key Words |
| STS 321, dynamic material model, high temperature deformation, formability |
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