Hydrogen-induced phase transformations in an austenitic stainless steel

Electrochemical hydrogen insertion in an austenitic stainless steel single crystal foil specimens resulted in high density of near surface crystal defects, a special dislocation structure and martensitic transformations. In addition to hydrogen charging time these changes were dependent on the orientation and the thickness of the foil specimens. In the (310) foils thin ε-martensite plates formed whereas in the (211) foils in addition to ε-martensite and dislocation pair structure also α′-martensite was present in thick areas of the foil. Independent of specimen orientation hydrogen insertion resulted in high density of near surface crystal defects.