Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb
Fire resistance of structural steels used in buildings is typically evaluated based on the ratio of the yield strength at 600 °C to that at room temperature. Fire-resistant steel shows a yield strength ratio of more than 2:3 between 600 °C and room temperature and achieves an excellent high-temperat...
| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-09-01
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| Series: | Materials & Design |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127520304160 |
| _version_ | 1818259613113384960 |
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| author | Hyo-Haeng Jo Chansun Shin Joonoh Moon Jae Hoon Jang Heon-Young Ha Seong-Jun Park Tae-Ho Lee Bong Ho Lee Jun-Ho Chung John G. Speer Kip O. Findley Taylor R. Jacobs Chang-Hoon Lee Sung-Dae Kim |
| author_facet | Hyo-Haeng Jo Chansun Shin Joonoh Moon Jae Hoon Jang Heon-Young Ha Seong-Jun Park Tae-Ho Lee Bong Ho Lee Jun-Ho Chung John G. Speer Kip O. Findley Taylor R. Jacobs Chang-Hoon Lee Sung-Dae Kim |
| author_sort | Hyo-Haeng Jo |
| collection | DOAJ |
| description | Fire resistance of structural steels used in buildings is typically evaluated based on the ratio of the yield strength at 600 °C to that at room temperature. Fire-resistant steel shows a yield strength ratio of more than 2:3 between 600 °C and room temperature and achieves an excellent high-temperature strength. Alloying elements such as Mo and Nb are used to improve the strength at elevated temperatures. In this study, the effects of the addition of Mo and Nb on the fire resistance of steel were carefully investigated using SEM, TEM, in-situ TEM, EPMA, 3D-APT, positron annihilation lifetime spectroscopy, and first principles calculations. The fire resistance in Mo and Nb added steel (Mo + Nb) was shown to be drastically improved compared to plain carbon steel (CMn). The improvement in the high-temperature strength in Mo + Nb was attributed to the precipitation of fine Nb-rich MX particles and a solid solution of Mo and Nb hindering the dislocation movement, and thereby minimizing the dislocation annihilation at elevated temperature. The solid solution of Mo and Nb lowers the vacancy formation energy and allows a vacancy to form more easily, leading to a large lattice distortion which results in a slower dislocation mobility in Mo + Nb. |
| first_indexed | 2024-12-12T18:18:13Z |
| format | Article |
| id | doaj.art-404cf278fc1f4dd4896f6276fd4cefcb |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-12-12T18:18:13Z |
| publishDate | 2020-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-404cf278fc1f4dd4896f6276fd4cefcb2022-12-22T00:16:13ZengElsevierMaterials & Design0264-12752020-09-01194108882Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and NbHyo-Haeng Jo0Chansun Shin1Joonoh Moon2Jae Hoon Jang3Heon-Young Ha4Seong-Jun Park5Tae-Ho Lee6Bong Ho Lee7Jun-Ho Chung8John G. Speer9Kip O. Findley10Taylor R. Jacobs11Chang-Hoon Lee12Sung-Dae Kim13Steel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaDepartment of Materials Science and Engineering, Myongji University, Yongin 17058, South KoreaSteel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaSteel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaSteel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaSteel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaSteel Department, Korea Institute of Materials Science, Changwon 51508, South KoreaCenter for Core Research Facilities, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, South KoreaHyundai Steel Company, Incheon 22525, South KoreaDepartment of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USADepartment of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USALos Alamos National Laboratory, Los Alamos, NM 87545, USASteel Department, Korea Institute of Materials Science, Changwon 51508, South Korea; Corresponding authors.Steel Department, Korea Institute of Materials Science, Changwon 51508, South Korea; Corresponding authors.Fire resistance of structural steels used in buildings is typically evaluated based on the ratio of the yield strength at 600 °C to that at room temperature. Fire-resistant steel shows a yield strength ratio of more than 2:3 between 600 °C and room temperature and achieves an excellent high-temperature strength. Alloying elements such as Mo and Nb are used to improve the strength at elevated temperatures. In this study, the effects of the addition of Mo and Nb on the fire resistance of steel were carefully investigated using SEM, TEM, in-situ TEM, EPMA, 3D-APT, positron annihilation lifetime spectroscopy, and first principles calculations. The fire resistance in Mo and Nb added steel (Mo + Nb) was shown to be drastically improved compared to plain carbon steel (CMn). The improvement in the high-temperature strength in Mo + Nb was attributed to the precipitation of fine Nb-rich MX particles and a solid solution of Mo and Nb hindering the dislocation movement, and thereby minimizing the dislocation annihilation at elevated temperature. The solid solution of Mo and Nb lowers the vacancy formation energy and allows a vacancy to form more easily, leading to a large lattice distortion which results in a slower dislocation mobility in Mo + Nb.http://www.sciencedirect.com/science/article/pii/S0264127520304160Fire resistanceHigh temperature strengthMoNbDislocationVacancy |
| spellingShingle | Hyo-Haeng Jo Chansun Shin Joonoh Moon Jae Hoon Jang Heon-Young Ha Seong-Jun Park Tae-Ho Lee Bong Ho Lee Jun-Ho Chung John G. Speer Kip O. Findley Taylor R. Jacobs Chang-Hoon Lee Sung-Dae Kim Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb Materials & Design Fire resistance High temperature strength Mo Nb Dislocation Vacancy |
| title | Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb |
| title_full | Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb |
| title_fullStr | Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb |
| title_full_unstemmed | Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb |
| title_short | Mechanisms for improving tensile properties at elevated temperature in fire-resistant steel with Mo and Nb |
| title_sort | mechanisms for improving tensile properties at elevated temperature in fire resistant steel with mo and nb |
| topic | Fire resistance High temperature strength Mo Nb Dislocation Vacancy |
| url | http://www.sciencedirect.com/science/article/pii/S0264127520304160 |
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