Fatigue crack propagation in pearlitic steel under pressurized gaseous hydrogen: influences of microstructure size and strength level

For the wall-thickness reduction of components destined for pressurized gaseous hydrogen, widespread use high-strength martensitic steels has long been desired. However, their strong susceptibility to hydrogen-assisted fatigue crack growth (HA-FCG) is still limiting proactive applications. Here, we instead focused on pearlite as another potential reinforcing agent development new hydrogen-compatible with acceptable cost performance. Fatigue (FCG) behavior three eutectoid different microstructure sizes (i.e., ferrite/cementite interlamellar spacing, colony and block sizes) strength levels was investigated in a 90 MPa hydrogen gas, an essential evaluation when attempting perform defect tolerant design used high-pressure gases.