This study investigated the surface pit corrosion of SS420J2 stainless steel accompanied by intergranular crack. To reveal the causes of surface pits and cracks, OM, SEM, and TEM analyses of the microstructures of the utilized SS420J2 were performed, as was simulated heat treatment. The intergranular cracks were found to have been induced by a grain boundary carbide of (Cr,Fe)23C6, which was identified by SEM/EDS and TEM diffraction analyses. The mechanism of grain boundary sensitization occurred at the position of the carbide, followed by its occurrence at the Cr depleted zone. The grain boundary carbide of (Cr,Fe)23C6 type precipitated during air cooling condition after a 1038 °C solid solution treatment. The carbide precipitate formation also accelerated at the band structure formed by cold working. Therefore, using manufacturing processes of cooling and cold working, it is difficult to protect SS420J2 stainless steel against surface pit corrosion. Several counter plans to fight pit corrosion by sensitization were suggested, involving alloying and manufacturing processes.

The aim of this study is to consider the effect hydrogen on dezincification behavior of Cu-Zn alloys. The investigations include microstructural observations with scanning electron microscope and chemical composition analysis with energy dispersive spectrometer. The dezincification layer was found to occur in high pressure hydrogen atmosphere, not in air atmosphere. In addition, the layers penetrated into the inner side along the grain boundaries in the case of hydrogen condition. The shape of the dezincification layers was porous because of Zn dissolution from the α or β phase. In the case of stress corrosion cracks formed in the Cu-Zn microstructure, the dezincification phenomenon with porous voids was also accompanied by grain boundary cracking.

본 연구에서는 농촌마을 쉼터가 농촌개발사업의 한 갈래로 계획되어 시행되고 있으나 주민의 요구를 충족시키지 못하고 있는 상황에서 새로이 계획하여 조성하는 마을 쉼터의 경우 대규모로 조성이 되는 경우가 많고 부지의 선정 및 확보에 문제가 있어 접근성이 떨어지는 경우가 많다. 이러한 문제점은 마을쉼터의 활용성을 떨어뜨리는 결과를 초래하게 된다. 농촌주민의 실질적인 쉼터로서의 활용을 위해서는 농촌마을의 유휴공간을 적절하게 활용하여 소규모 쉼터를 분산하여 조성하는 것이 바람직하다고 사료된다. 따라서 본 연구에서는 유휴공간을 활용한 농촌마을 쉼터의 디자인을 제안함으로써 후행연구에서 다양한 디자인의 마을쉼터가 연구되어 농촌마을 주민들에게 생활의 편의성을 제공하고 커뮤니티 형성에 보다 적극적으로 기여하며 물리적 환경개선을 통하여 쾌적성 및 심미성을 증진하는데 도움이 되기를 기대한다. 그에 따라 농촌마을 쉼터에 대해 고찰하고 농촌마을 실정에 맞는 유휴공간을 활용한 마을쉼터 디자인을 제안하여 농촌마을의 특색을 담아 활용성을 높이고자한다.