Effect of static hydrogen charging on corrosion and hydrogen embrittlement of High strength steel

The corrosion and hydrogen embrittlement properties of 1000MPa grade high strength steel in sea water are studied by weightlessness test under the condition of cathode polarization and slow strain tensile test (SSRT) after static hydrogen filling . The fracture characteristics of the specimen are observed with SEM. The results show that the most positive cathodic protection potential of high strength steel in sea water is -780 mV. The tensile test shows that with the negative shift of the polarization potential and the increase of hydrogen charging time, the elongation and the shrinkage of the high strength steel decrease gradually. The fracture mode transforms from ductile to cleavage and intergranular fracture. It can be seen that the toughness of the material decreases and the hydrogen embrittlement sensitivity increases gradually. Especially, the effect of polarization potential on hydrogen embrittlement of materials is more obvious.