Hydrogen-Assisted Fracture Mechanisms in Ultrafine-Grained CrNi Austenitic Stainless Steels with Different Initial Microstructures

We investigated the effect of electrolytic hydrogen-charging on regularities of plastic flow, strength and fracture mechanisms of AISI 316L and 321 austenitic stainless steels. In the steels, an ultrafine-grained structure of various morphologies was formed using methods of warm abc-pressing and thermomechanical treatment (cold rolling and annealing). Hydrogen-charging of ultrafine-grained steels reduces their yield strength and elongation. The high dislocation density and low-angle boundaries inhibit the effects of hydrogen embrittlement in 316L and 321 steels.