Measurement of Fatigue Crack Growth Rates for SA-372 Gr. J Steel in 100 MPa Hydrogen Gas Following Article KD-10

The objective of this work is to enable the safe design of hydrogen pressure vessels by measuring the fatigue crack growth rates of ASME code-qualified steels in high-pressure hydrogen gas. While a design-life calculation framework has recently been established for high-pressure hydrogen vessels, a material property database does not exist to support the analysis. This study addresses such voids in the database by measuring the fatigue crack growth rates for three heats of ASME SA-372 Grade J steel in 100 MPa hydrogen gas at two different load ratios (R). Results show that fatigue crack growth rates are similar for all three steel heats and are only a mild function of R. Hydrogen accelerates the fatigue crack growth rates of the steels by at least an order of magnitude relative to crack growth rates in inert environments. Despite such dramatic effects of hydrogen on the fatigue crack growth rates, measurement of these properties enables reliable definition of the design life of steel hydrogen containment vessels.