Fatigue crack-growth properties of ductile cast iron in hydrogen gas with oxygen impurity at various temperatures

Ductile cast irons have for long been widely used across diverse industries, due to their excellent sliding properties, remarkable castability and notable ductility. Nevertheless, the hydrogen embrittlement of these irons is yet to be comprehensively understood. This study aimed to uncover their potential for application in hydrogen service. The primary objective was to comprehend the effects of various factors such as temperature, oxygen impurity levels and loading frequency on the fatigue crack-growth (FCG) properties of the ductile cast iron, JIS-FCD400, in hydrogen gas environments. Notably, the material exhibited stable FCG behavior in pure hydrogen. Moreover, some intriguing insights emerged, indicating that oxygen impurity and elevated temperature tend to mitigate the detrimental effects of hydrogen. Collectively, these findings lay the groundwork for the plausible feasibility of incorporating ductile cast irons into hydrogen service.