Abstract
Although fuel-cell vehicles are almost put on the market, supply system for hydrogen gas has many problems to be solved, such as hydrogen embrittlement. Hence from cracks hydrogen gas is easy to be leaked, which means loss of water on earth, nondestructive test (NDT) of high-pressure hydrogen cylinders is important. Leaking hydrogen gas means loss of water on earth. In this study we discuss NDT on ferrous metals for conventional commercial use. Since magnetization is approach to anhysteresis curve under plasticity, additional plastic deformation in high-pressure hydrogen cylinders can be detected to evaluate its deterioration. We also discuss residual magnetic distribution caused by stress-induced martensite transformation can detect ununiform mechanical properties in the cylinders.
