Abstract
The 6061 aluminum alloy is being used as a liner material of a high-pressure hydrogen tank for fuel cell vehicles. At present in Japan, maximum pressure is limited to 35MPa which causes the mileage per a filling to be less than that of gasoline vehicles. Thus, raising the initial pressure to 70MPa by replacing the 6061 alloy by a higher-strength aluminum alloy is demanded to increase the mileage. However, it is known that some aluminum alloys cause hydrogen embrittlement. In addition, the cause of hydrogen embrittlement and behavior of hydrogen in materials has not been elucidated yet. In order to check the safety of the hydrogen tank, investigation on the hydrogen assisted embrittlement as well as on the behavior of hydrogen is required. Slow strain rate technique (SSRT) test and thermal desorption spectroscopy (TDS) can be used to examine the resistance to hydrogen embrittlement and analyze the hydrogen behavior, respectively. In this study, the resistance to hydrogen embrittlement of a 6061 aluminum alloy with high Si content that has higher strength than ordinary 6061 alloy has been studied by SSRT tensile test. Also, the behavior of hydrogen has been investigated by means of TDS.
