Fatigue characteristics of low carbon steel in hydrogen gas environment

In order to investigate the effect of hydrogen environment on fatigue crack growth characteristics of a low carbon steel JIS S10C, fatigue crack growth tests were conducted in a low pressure hydrogen gas environment. Fatigue crack growth rate in hygragen gas is higher than that in nitrogen gas. It seems that a crack in the range of low growth rate prefers to propagate along the grain boundaries under hydrogen environment while in the range of high growth across the grains accompanied by brittle striation patterns or river patterns. It is important to clarify how hydrogen affects the crack growth behavior of different stages of crack growth.