Fatigue behavior of hydrogen pre-charged low alloy Cr-Mo steel

Aim of the present work is to study the mechanical behavior in presence of hydrogen of a quenched&tempered low alloy Cr–Mo steel, AISI 4130, used for hydrogen storage and transportation. The sensitivity of steels to hydrogen embrittlement is generally determined by means of two kinds of experimental procedures to hydrogen charge the specimens: gaseous hydrogen in environmental chambers or autoclaves or H2S solution (recommended by NACE standard). In this work experimental tests are carried out on specimens pre-charged by means of an electrochemical method. A campaign of toughness and fatigue crack growth tests is performed on specimens without and with pre-charged hydrogen. The results are compared and discussed with other, from literature, obtained by following more traditional testing procedures. By this comparison the adopted experimental procedure, that is safer and easier, seems to provide useful information.