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Vol.43, No.1, 44 ~ 54, 2005
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| Title |
| Influence of the Addition of Ce on Microstructural Variation and SCC Behavior of Alloy 600 |
| 권오철 Oh Chul Kwon , 이용선 Yong Sun Yi , 임연수 Yun Soo Lim , 정만교 Man Kyo Jung , 김정수 Joung Soo Kim |
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| Abstract |
| High purity model alloys with major composition Ni-15Cr-9Fe-0.03C (600CEO) and Ni-15Cr-9Fe-0.03C-0.04Ce (600CE4) were produced. Using these model alloys the effect of alloying element Ce on the SCC behavior of Alloy 600 was evaluated in a caustic solution. To obtain carbides precipitated on grain boundaries, the thermal treatment was performed on both the solution annealed model alloys. Microstructural examinations using SEM and TEM EDX showed that the same structural carbides, Cr_(7)Cc₃, were precipitated on both the alloys and no significant difference in the amount of Cr depletion along grain boundaries was observed between the two model alloys. However, it was shown that the coverage of grain boundary carbides was higher in the Ce-bearing alloy (600CE4). The SCC susceptibility of the alloys was investigated in 40%NaOH solution at 315℃. Being evaluated in terms of the maximum crack depth, the SCC susceptibility of the alloy turned out to be reduced by the addition of Ce. The increased resistance to the SCC in the alloy 600CE4 was considered to be attributable to the increased coverage of grain boundary carbides. (Received September 30, 2004) |
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| Key Words |
| Stress corrosion cracking, Cerium, Alloy 600, Intergranular carbide, Coverage |
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