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Vol.48, No.11, 974 ~ 981, 2010
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| Title |
| Tensile Properties of Energy Saving Wire (ESW) with respect to Temperatures of High Frequency Induction Heat Treatment |
| 조경목 Kyung Mox Cho , 최일동 Il Dong Choi , 박영도 Yeong Do Park , 안순태 Soon Tae Ahn , 박지태 Ji Tae Park , 강남현 Nam Hyun Kang , 남대근 Dae Geun Nam , 이진범 Jin Beom Lee |
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| Abstract |
| Various types of steel, namely, 0.35C, 0.2C-Cr, and 0.2C-Cr-Mo steels, were quenched and tempered by high-frequency induction heat treatment. The type, size, and spheroidization of the carbides varied depending on the tempering temperatures (450~720℃). During the tempering process, the carbide was precipitated in the martensite matrix. The 0.35C, 0.2C-Cr, and 0.2C-Cr-Mo steels contained carbides that were smaller than 120 nm. The carbide was spheroidized as the tempering temperature increased. Owing to the fine microstructure and spheroidization of the carbides, all three steels had a high tensile strength as well as yield ratio and reduction of area. In the case of the 0.2C-Cr steel, the use of Cr as an alloying element facilitated the precipitation of alloyed carbides with an extremely small particle and resulted in an increase in the spheroidization rate of the carbides. As a result, a large reduction of area was achieved (>70%). The 0.2C-Cr-Mo steel had the highest tensile strength because of the high hardenability that can be attributed to the presence of alloying elements (Cr and Mo). Quenching and tempering steels by induction heat treatment resulted in a high strength of over 1 GPa and a large reduction of area (>70%) because of the rapid heating and cooling rates. |
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| Key Words |
| metals, nanostructured materials, tempering, ductility, precipitation, strength |
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