• 건강소식
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• v.36 no.8
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• pp.14-15
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• 2012

적지 않은 흰머리마저 매력적으로 보이는 50세 배우, 최민식은 막강한 힘을 가진 배우다. '파이란'과 '취화선', '올드보이', '친절한 금자씨', '악마를 보았다', '범죄와의 전쟁'까지 그 막강한 캐릭터를 연기할 수 있는 힘은 어디서 오는 것일까?

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.234.1-234.1
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• 2003

• Proceedings of the KWS Conference
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• 1998.05a
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• pp.133-137
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• 1998

• Proceedings of the KWS Conference
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• 1994.05a
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• pp.57-59
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• 1994

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.364.2-364.2
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 2003.10a
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• pp.461.2-461.2
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.271.1-271
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• 1999

• Journal of the Korean Society for Nondestructive Testing
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• v.15 no.4
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• pp.549-560
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• 1996

The purpose of this study is to investigate the usefulness of small punch(SP) test using miniaturized specimens as a method for fracture strength evaluation of CANDU pressure tube embrittled by hydrogen. According to the test results, the fracture strength evaluation as a function of hydrogen concentration at $-196^{\circ}C$ was much better than that at room temperature, as the difference of SP fracture energy(Esp) with hydrogen concentration was more significant at $-196^{\circ}C$ than at room temperature for the hydrogen concentration up to 300ppm-H. It was also observed that the peak of average AE energy, the cumulative average AE energy and the cumulative average AE energy per equivalent fracture, strain increased with the increase of hydrogen concentration. From the results of load-displacement behaviors, Esp behaviors, macro- and micro-SEM fractographs and AE test it has been concluded that the SP test method using miniaturized specimen($10mm{\times}10mm{\times}0.5mm$) will be a useful test method to evaluate the fracture strength for CANDU pressure tube embrittled by hydrogen.

• Journal of Energy Engineering
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• v.18 no.1
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• pp.56-62
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• 2009

With weld metal of X65 steel, hydrogen was charged by electro-chemical method and mechanical behavior such as strength was measured by the small punch test. The weld metal was more sensitive to hydrogen charging than the case of base metal. The small punch (SP) strength was decreased as the hydrogen contents increased. Magnitude of strength decrease was dependent on current density, temperature, charging time. Current density and charging time have significant effect on the mechanical properties but temperature of electrolyte has limited effect. Fractured surfaces of the tested specimens were observed by SEM (scanning electron microscope). In the hydrogen charged specimens cleavage fracture were observed, which is consistent with the SP test results. Since the testing procedure for studying hydrogen embrittlement proposed in this study has shown good reproducibility of test results, the proposed method can be assumed to be a reliable test procedure. Using the electrochemical charging and the small punch test, the change of SP strength for X65 weld metal due to hydrogen embritlement could be evaluated sensitively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.11
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• pp.1011-1020
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• 2017

This study was conducted to investigate the material properties of stainless steel 316L specimens of untreated and UNSM treated material, hydrogen attacked material(100 bar, $300^{\circ}C$ at 120 h) and UNSM treated hydrogen attacked material at room temperature. Results demonstrated that the hydrogen attacked materials showed a tendency toward a slightly decreased fatigue strength, while the hydrogen embrittlement effect was smaller than the S-N curve of conventional untreated material. As compared to untreated material, the fatigue limit of the UNSM treated material increased by 43.8%, while it was 57.1％ higher in the UNSM treated hydrogen attacked material than in untreated hydrogen attacked material. The plastic deformation layer was ${\sim}152{\mu}m$ thick, as confirmed by maps showing the level of local plastic deformation affected by the UNSM treatment in three ways: an image quality map, inverse pole figure map, and kernel average misorientation map captured via electron back scatter diffraction. Owing to hydrogen embrittlement, about 90％ of surface cracks were smaller than the average grain size of $35{\mu}m$.