Effects of Static and Dynamic Strain Aging on Hydrogen Embrittlement in TWIP Steels Containing Al

Al effects on strain aging and resistance against hydrogen embrittlement were examined in Fe-18Mn-0.6C-based twinning-induced plasticity steels deformed at different strain rates. The Fe-18Mn-0.6C steel showed hydrogen-induced fracture when it had been pre-deformed at a strain rate of 1.7×10–6 s–1. The hydrogen-induced fracture was suppressed by increasing strain rate and increasing Al content. From the viewpoint of material strengthening by strain aging, we found two important factors improving the resistance to the hydrogen embrittlement; (1) suppression of dynamic strain aging by increasing strain rate and Al content, and (2) suppression of static strain aging under loading by the Al addition.