Hydrogen-affected fatigue crack propagation at various loading frequencies and gaseous hydrogen pressures in commercially pure iron

Tomoki Shinko (1) , Gilbert Hénaff (1, 2) , Damien Halm (1, 2) , Guillaume Benoit (1, 2) , Giovambattista Bilotta (1, 2) , Mandana Arzaghi (1, 2)

1 PPrime [Poitiers] - Institut Pprime [UPR 3346]
2 ENDO - ENDOmmagement et durabilité [Institut Pprime]

Hydrogen-Affected Fatigue Crack Growth (HAFCG) in commercially pure iron has been characterized in terms of hydrogen gas pressure, loading frequency and stress intensity factor range ΔK. A higher hydrogen gas pressure decreases the critical value of ΔK triggering the HAFCG enhancement, and a lower loading frequency increases the HAFCG enhancement. Intergranular FCG in the non-accelerated regime is likely caused by the hydrogen-induced microvoid coalescence along the grain boundary, while a brittle cyclic cleavage fracture in the accelerated regime can be explained in terms of crack tip sharpening and hydrogen-enhanced decohesion process.

Mots clés: Hydrogen embrittlement; Fatigue crack propagation; Commercially pure iron; Intergranular fracture; Crack tip plasticity

Domaines: Mécanique des fluides [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Milieux fluides et réactifs; Energie électrique; Thermique [physics.class-ph]; Vibrations [physics.class-ph]; Physique mathématique [math-ph]; Physique Quantique [quant-ph]; Acoustique [physics.class-ph]; Biomécanique [physics.med-ph]; Matériaux; Polymères; Acoustique [physics.class-ph]; Automatique / Robotique; Electromagnétisme

Tomoki Shinko, Gilbert Hénaff, Damien Halm, Guillaume Benoit, Giovambattista Bilotta, et al.. Hydrogen-affected fatigue crack propagation at various loading frequencies and gaseous hydrogen pressures in commercially pure iron. International Journal of Fatigue, 2019, 121, pp.197-207. ⟨10.1016/j.ijfatigue.2018.12.009⟩. ⟨hal-02283331⟩