The hydrogen embrittlement could lead to big damages in bolt/nut, fittings, especially, high pressure valve and high leak-proof valve and so on. Thus, special alloy, for instance, such as Monel and Inconel, is recently used to suppress the problems of hydrogen embrittlement in semiconductor facilities, FCEV(fuel cell electric vehicle) and hydrogen gas stations. The purpose of this study is to investigate the characteristics according to ratio change between drawing and extrusion of Monel material within elastic limit through numerical analysis. As the results, the possibility of plastic deformation in case of drawing was greater than that of extrusion. Consequently, the safety factor related to plastic deformation shows the results depending on the ratio change of force between drawing and extrusion.

As environmental concerns escalate, the increase in recycling of aluminum scrap is notable within the aluminum alloy production sector. Precise control of essential components such as Al, Cu, and Si is crucial in aluminum alloy production. However, recycled metal products comprise various metal components, leading to inherent uncertainty in component concentrations. Thus, meticulous determination of input quantities of recycled metal products is necessary to adjust the composition ratio of components. This study proposes a stable input determination heuristic algorithm considering the uncertainty arising from utilizing recycled metal products. The objective is to minimize total costs while satisfying the desired component ratio in aluminum manufacturing processes. The proposed algorithm is designed to handle increased complexity due to introduced uncertainty. Validation of the proposed heuristic algorithm's effectiveness is conducted by comparing its performance with an algorithm mimicking the input determination method used in the field. The proposed heuristic algorithm demonstrates superior results compared to the field-mimicking algorithm and is anticipated to serve as a useful tool for decision-making in realistic scenarios.

In this study, corrosion potentials were evaluated according to the composition ratio of Zn-Al alloy. Alloys were fabricated according to the composition ratio of Zn-Al. The corrosion potential was measured according to ASTM B 627-84. As a result of the study, the measured value of corrosion potential tended to increase with increasing composition ratio of Al.

In this study, corrosion potentials were evaluated according to the composition ratio of Zn-Al alloy. Alloys were fabricated according to the composition ratio of Zn-Al. The corrosion potential was measured according to ASTM B 627-84. As a result of the study, the measured value of corrosion potential tended to increase with increasing composition ratio of Al.