Hot-press forming(HPF) steel can be applied successfully to auto parts because of its superior mechanical properties. However, its resistances to aqueous corrosion and the subsequent hydrogen embrittlement(HE) decrease significantly when the steel is exposed to corrosive environments. Considering that the resistances are greatly dependent on the properties of coating materials formed on the steel surface, the characteristics of the corrosion and hydrogen diffusion behaviors regarding the types of coating material should be clearly understood. Electrochemical polarization and impedance measurements reveal a higher corrosion potential and polarization resistance and a lower corrosion current of the Al-coating compared with Zn-coating. Furthermore, it was expected that the diffusion kinetics of the hydrogen atoms would be much slower in the Al-coating, and this would be due mainly to the much lower diffusion coefficient of hydrogen in the Al-coating with a face-centered cubic structure. The superior surface inhibiting effect of the Al-coating, however, is degraded by the formation of local cracks in the coated layer under severe stress conditions, and therefore further study will be necessary to gain a clearer understanding of the effect of cracks formed on the coated layer on the subsequent corrosion and hydrogen diffusion behaviors.

Although most of the automobile bodies are made of steel, the application of aluminum alloy sheet with high strength is under consideration for the development of environmentally friendly lightweight body for fuel economy improvement and carbon dioxide emission reduction. In the case of some inner plates, application of magnesium alloy sheet is examined. TRB plate has been studied mainly for weight reduction and rigidity reinforcement of steel plate parts. Recently, research on aluminum TRB rolled plate for light and environment friendly automobile application has been started, It is expected that the development of eco - friendly TRB rolling material made of light alloy will increase as the importance of light weight body for future energy efficiency increases. Therefore, in this study, we tried to obtain the technology to improve the quality of the product by pre - verifying the cooling performance of the hot forming process through the heat flow analysis and evaluating the cooling performance through the temperature distribution analysis. As a result, it was found that the temperature distribution through the flow velocity problem and the flow of the cooling channel can influence the quality of the final product through different heat distribution and cooling time depending on the shape of the mold and the product.

We have observed the deuterated methanol, CH3OD, toward the hot core MM1 in the massive star-forming region DR21 (OH) using the Submillimeter Array with a high angular resolution of about 1 arcsecond. The position of the hot core associated with the sub-core MM1a was confirmed to coincide with the continuum peak where an embedded young stellar object is located. The column density of CH3OD was found to be about (2 ± 1) x 1016 cm-2 toward the MM1a center. The abundance ratio CH3OD/CH3OH was measured to be ~ 0.45, which is about the median value for low mass star-forming cores but much larger than those of the massive star-forming cores. The ratio is believed to change depending on, for example, the chemical condition, the temperature and the density of the source. This ratio may further depend on the evolutionary phase especially in the massive-star-forming cores. The sub-core MM1a is thought to be in the very early phase of star formation. This large abundance ratio found in this source indicates that even the massive star-forming cores, during a relatively short period in the very early stage of star formation, may also show a chemical state resulted from the cold and dense pre-collapsing phase, the enhanced deuteration as found in low mass star-forming cores.