| Title |
Effect of Annealing Temperature on the Microstructure, Tensile Properties, and Fracture Behavior of Cold-Rolled High-Mn Light-Weight Steels |
| Authors |
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) |
| DOI |
https://doi.org/10.3365/KJMM.2017.55.5.363 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
low-density steel; annealing; microstructure; beta-manganese; tensile properties; cold-rolling |
| 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) |