Influence of hydrogen on delayed fracture of RPV steels

Influence of hydrogen on the toughness of irradiated reactor pressure vessel steels

“…For example, the uptake of hydrogen and an enhanced susceptibility for embrittlement were proved for irradiated steels with austenitic claddings under RPV conditions [4]. Splichal et al [4,5], Brinkman and Beston [6] and Takaku et al [7,8] specified critical hydrogen concentrations of P2.5-4 wt ppm for degradation of the mechanical properties both in the unirradiated and the irradiated condition. Kimura et al [9] proved that the critical hydrogen charging current density of neutron-irradiated martensitic steel was smaller than that of unirradiated one.…”

Small-angle neutron scattering study on the effect of hydrogen in irradiated reactor pressure vessel steels

“…According to Brinkman and Beeston [2] there is only a total loss of the tensile ductility for irradiated steels if the strength is larger than 1200 MPa and the concentration of hydrogen is higher than 1 ppm. For steels of lower strength, hydrogen concentrations of P2.5-4 ppm yield a degradation of the mechanical properties both in the unirradiated and in the irradiated conditions [2][3][4][5][6][7][8][9]. Irradiation enhances the effect, especially if the irradiation temperature is low.…”