2013 Volume 54 Issue 12 Pages 2285-2290
Carbon steels with high resistance to hydrogen-assisted fatigue crack growth were successfully produced by the addition of a carbide-forming element and the refinement of ferrite grain size. In carbon steels containing vanadium, titanium, or niobium, fine carbide (VC, TiC, or NbC, respectively) precipitation and the refinement of grain size below 1 µm were achieved by caliber rolling at 833 K. Hydrogen charging increased the fatigue crack growth rate in standard JIS-S45C carbon steel to about 25 times that in uncharged steels. In contrast, in carbon steels containing carbide-forming elements, hydrogen-assisted fatigue crack growth was either absent or at most two times faster than that in uncharged steels.