Factors influencing the extent of hydrogen-enhanced brittle cracking in a Cu-strengthened HSLA steel during monotonic loading

The extent of brittle crack as a function of hydrogen charging conditions was studied for a HSLA steel using circumferentially notched cylindrical tensile samples. Two different notch depths were used. The effect of hydrogen could be well represented by an effective hydrogen potential which was defined using a representative hydrogen concentration and a diffusive time parameter, for relatively faster strain rates. The high triaxiality in deep-notched samples led to the initiation of ductile failure mechanisms overwhelming the brittle cracking process.