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Vol.48, No.11, 1021 ~ 1028, 2010
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| Title |
| Impact Toughness and Microstructure of the Weld Metal by Tandem Electro-Gas Welded EH40 Steel |
| 이재현 Je Hyun Lee , 박태규 Tae Gyu Park , 김호경 Ho Kyeong Kim , 김정민 Jeon Min Kim , 유혜영 Hye Young Yoon , 정원지 Won Jee Chung |
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| Abstract |
| The charpy impact property was lower at the surface and middle regions than that at the root region in metal welded by Tandem EGW of 82 mm thick EH40-TM steel plates. Temperature distribution in the weld sample and the heating/cooling temperature throughout the various regions in the weld metal were estimated by the commercial weld simulation program SYSWELD. The microstructure of the weld metal consisted of acicular ferrite and grain boundary ferrite. Grain boundary ferrite in the acicular ferrite matrix was found more in the surface and middle regions than in the root region, and the acicular ferrite was also coarser in the surface and middle regions where the impact toughness was lower and the input temperature was higher. Our results indicated that the impact toughness property was related to the microstructure morphology, the distribution of grain boundary ferrite, and the acicular ferrite. |
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| Key Words |
| tandem EGW, EH40, weld simulation, cooling rate, acicular ferrite, grain boundary ferrite |
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