Effect of Hydrogen Gas on the Growth of Small Fatigue Crack in JIS-SCM435

摘要: The fatigue crack growth (FCG) from a small hole in low alloy steel JIS-SCM435 round bar was investigated using tension-compression tests 0.7 MPa hydrogen gas and ambient air. In the higher FCG rate regime (e.g. da/dN > 108 m/cycle), accelerated compared to On other hand, lower < rather slower than that There no noticeable difference limits between these two atmospheres. respective atmospheres showed typical behavior, i.e. for cracks were much greater those large obtained by compact tension (CT) specimen when they at same ΔK level. order unify such discrepancy of behavior crack, strain intensity factor range ΔKe adopted. As result, data various sizes gathered narrow band, effect successfully evaluated with intensity. Moreover, life predicted based on da/dN-ΔKe relation. reproduced S-N curve conservative agreement experiments.