Effect of shearing prestrain on the hydrogen embrittlement of 1180 MPa grade martensitic advanced high-strength steel

This work investigated the effect of shearing prestrain on hydrogen embrittlement. The strength and ductility values were similar to those in air for hydrogen precharging before tensile testing, but the ductility decreased significantly for tensile testing with in-situ hydrogen charging due to intergranular fracture initiation at the specimen surface. In contrast, there was a significant decrease in ductility for the hydrogen precharged steel after prestrain. The hydrogen-facilitated fracture was transgranular. The hydrogen fracture grew by fracture tip blunting, new fracture initiation, and coalescence, consistent with a hydrogen enhanced localized plasticity (HELP) mechanism.