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Vol.55, No.5, 363 ~ 372, 2017
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| Title |
| Effect of Annealing Temperature on the Microstructure, Tensile Properties, and Fracture Behavior of Cold-Rolled High-Mn Light-Weight Steels |
| 이재현 Jae-hyun Lee , 박성준 Seong-jun Park , 문준오 Joonoh Moon , 강전연 Jun-yun Kang , 박준영 Jun-young Park , 이태호 Tae-ho Lee , 조경목 Kyung Mox Cho |
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| Abstract |
| The effects of the annealing temperature on the microstructure and tensile properties of cold-rolled light-weight steels are investigated using two Fe-30Mn-xAl-0.9C alloys that contain different Al content. The initial alloy microstructure is composed of a single austenite or a mixture of austenite and ferrite depending on the nominal aluminum content. For the alloy with 9 wt% Al content, the recrystallization and grain growth of austenite occurrs depending on the annealing temperature. However, for the alloy with 11 wt% Al content, the β-Mn phase is observed after annealing for 10 min at 550~800 ℃. The β-Mn transformation kinetics is the fastest at 700 ℃. The formation of the β-Mn phase has a detrimental effect on the ductility, and this leads to significant decreases in the total elongation. The same alloy also forms κ-carbide and DO3 ordering at 550~900 ℃. The investigated alloys exhibit a fully recrystallized microstructure after annealing at 900 ℃ for 10 min, which results in a high total elongation of 25~55% with a high tensile strength of 900~1170 MPa. (Received October 21, 2016; Accepted November 21, 2016) |
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| Key Words |
| low-density steel, annealing, microstructure, beta-manganese, tensile properties, cold-rolling |
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