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Hyundai Motor Company has developed hydrogen fuel cell vehicles (FCV) based on its SUV, Santa Fe. As the hydrogen fuel cell power plant runs at near ambient pressure, parasitic loss due to its operation is fully minimized and the noise level of the air supply subsystem is extremely low. The Santa Fe FCV has been built to feature roomy passenger space and cargo capacity identical to that of a standard, gasoline-powered Santa Fe, because of its compact fuel cell power plant. In addition, lightweight aluminum body-components help to keep a power-to-weight ratio similar to that of a conventional SUV. Hyundai Motor Company, as a full member of California Fuel Cell Partnership, is now operating the Santa Fe FCV's on real roads in California. In this paper, the configuration and performance test results of the Santa Fe FCV will be described.

Recent legislative and environmental pressures on the automotive industry to produce light-weight fuel-efficient vehicles with lower emissions have led to a requirement for traditional steel components to be replaced by advanced materials such as aluminium, magnesium and metal matrix composites. Those social pressures have also led to a claim for conventional vehicles to be replaced by the next generation vehicles (NGV) such as electric vehicles, hybrid electric vehicles, fuel cell vehicles and 3-litre car etc. This has led to a complete re-analysis of the design and manufacturing routes, with the emergence of advanced technologies as a viable process for the production of high volume, low cost, high integrity automotive components. In this paper the development and application of advanced materials and key technologies including the next generation vehicles will be described and discussed in terms of vehicle performance and cost effectiveness.

Due to the environmental problem like as CO2 emission, energy problem and etc., many car makers are trying to reduce the weight of the vehicle. The most effective way to reduce the weight of vehicle is to use lighter materials, aluminum, magnesium, plastics. And weight reduction of body is more effective than the others. There are two kinds of lightweight body, aluminum monocoque body and aluminum space frame body. Aluminum space frame body has many advantages from the space frame structure and the use of lighter materials. So, many car makers are developing aluminum space frame body and in mass production of some kinds of car, eg. Sports car, electric vehicle and etc. For these reason, we have developed and aluminum space frame body vehicle with ATOZ model base. Using FEM analysis, we designed sections of extrusions(6061) and fabricated spaceframe skeleton by ARC welding.

The stiffness of autobody largely depend on the joint strength of welding spots. Weak welding joints lead to inferior stiffness, which lowers vehicle performance such as ride & handling and NVH(Noise Vibration Harshness). Resistance spot welding, major joining method of autobody, produces superior joint strength but its fatigue limit(fatigue strength at 107 cycle) is inferior, which implies that joint strength may be greatly affected by the fatigue. Mechanical clinching, on the other hand, has lower joint strength but its fatigue limit is higher than that of spot welding. This paper focused on the behavior of joint strength under cyclic loading in both resistance spot welding and mechanical clinching. The deterioration of joint strength during fatigue testing was examined by measuring monotonic shear tension force as a function of fatigue cycles at a given cyclic load.

To develop catalysts for natural gas vehicles the effects of precious metal, washcoat and catalysts combination on the removal of methane (CH4), non methane hydrocarbon (NMHC), CO and NOx were investigated. The precious metal formula studied were Pt/Rh, Pd/Rh, Pt/Pd/Rh (trimetal) and Pd only. Two types of washcoats with different compositions and coating structures were used. Model gas tests were carried out for eight kinds of catalysts and dual catalysts consisted of two single catalysts. Through FTP75 vehicle test, three 50,000 miles approximate aged catalytic converters with dual beds were evaluated. The experimental results showed that Pd only and trimetal catalysts had good catalytic performance over the CH4-CO-NO simulated gas composition. Dual bed catalysts had better CH4, CO and NO conversion performance and light off characteristics than single bed catalysts.

The micro alloyed steels(MAsteels) developed to reduce the manufacturing cost of automotive parts, have reasonable mechanical properties, but their lower toughness compared to conventional quenched and tempered steels(QT steels) has limited their application to the automotive components. To understand the fracture behavior of MA steel, the simple mechanical properties were investigated and three kinds of fracture related tests; three point bend test, compact specimen fracture toughness test and fatigue test were performed. From the results of three point bend tests, absorbed energy for both materials, except for V-notched specimen of MA steels, was independent of strain rate with each notch geometry. And, MA steels were more sensitive to notch geometry than QT steels. Therefore, in practical application, components need to be designed to have low restrained notch geometry.

Full scale developments of microalloyed steel forgings (0.4C-V modified) for connecting rods and wheel hubs are discussed in this presentation. Mechanical properties were evaluated in terms of various processing parameters and the resulted microstructures. Tensile strength obtained in MA steel by air cooling was equal to or greater than that produced in the quenched and tempered steel. Generally, increasing austenitizing temperature (900 C - 1300 C ) and cooling rate (box cooling< air cooling< fan cooling ) resulted in increased tensile strength. Impact toughness did not show the significant dependence of cooling rate, while decreasing austenitizing temperature enhanced impact toughness. The impact toughness of the microalloyed steel forgings obtained from optimum process showed poorer performance than that of quenched and tempered steel forgings but satisfied the specification made from the design view point.

This study was carried out to investigate the CO2 laser weldability of aluminum alloy sheets for the welding of hemmed region. Efforts were made to obtain the best bead dimension for hemming welding. Thus, a following criterion was formulated: a hemming bead which has less than 0.8 mm of welding depth and more than 1.0 mm of welding width works satisfactorily for hemming joint in terms of both strength and visual appearance. The dimension of hemming bead was greatly affected by surface conditions as well as welding parameters. Clean surface condition coupled with helium shielding gas produced a most sound welding bead. The effect of lubricant on the formation of welding defect was also investigated. It was found that the welding defect, i.e., porosity in the weld zone, was caused by the lubricant at the surface and degraded the strength of weld joint. The laser welding did not soften both the heat affected zone (HAZ) and weld zone of aluminum alloy sheets in this study.