Understanding of hydrogen effect on local mechanical properties of metals is important for understanding hydrogen embrittlement mechanisms. The effect of thermal gaseous hydrogen precharging on the nanomechanics of SUS310S and SUS304 austenitic stainless steels has been investigated using a combination of nanoindentation and atomic force microscopy (AFM). It is observed that hydrogen precharging decreases the first excursion load in load versus displacement curves and enhances the slip steps around indentations for both the materials, which experimentally support the hydrogen-enhanced localized plasticity (HELP) mechanism. The nanohardness in SUS310S stable austenitic stainless steel is increased by hydrogen precharging while that in SUS304 metastable austenitic stainless steel is decreased by hydrogen precharging. The hydrogen-induced hardening in SUS310S and softening in SUS304 are discussed in terms of the hydrogen/deformation interaction and the effect of hydrogen on strain-induced martensite transformation.

This content is only available via PDF.
You do not currently have access to this content.