open access

https://hdl.handle.net/2115/52001

Hydrogen effects on tensile property of pure iron with deformed surface

英語

Dislocation structure

2013-01-10

Elsevier B.V.

Materials Science and Engineering: A

560

332-338

To study the interaction of hydrogen and surface structure of iron, two types of tensile test are carried out under hydrogen gas environment and cathodic hydrogen charging condition. According to the tensile tests, hydrogen induces reduction of flow stress (softening) for the specimens without deformed surface, but increase of flow stress (hardening) for the one with deformed surface. The results of jump tests signify that hydrogen enhances the dislocation mobility by reducing the thermal activation volume for overcoming barriers, and because of this, in the samples with smooth surface, homogeneously distributed hydrogen leads to the softening effect. On the other hand, the deformed layer just under the surface has larger solubility of H due to trap sites provided by dislocation cell structures. As a result of hydrogen shielding effect, the strong interaction between dislocations in surface layer and multiplication of new defects causes the hardening effect.

学術雑誌論文

Accepted Manuscript

0921-5093