Dynamic Behaviors of Hydrogen in Martensitic T91 Steel Evaluated by Using the Internal Friction Method

Hydrogen atoms are electrochemically introduced into commercial martensitic T91 steel, and the hydrogen dynamic behaviors are investigated by internal friction (IF) technology. A complex spectrum with multicomponent peaks is detected in the hydrogen-charged T91 steel in the temperature range of 135-290 K. Analysis of peak configuration reveals that the multicomponent peaks consist of one relaxational peak and two non-relaxational peaks. The mechanism of the wide relaxational component is ascribed to the combination of a hydrogen Snoek-like diffusion process and the interaction of hydrogen with movable dislocations, while the two non-relaxational peaks are preliminarily suggested to be caused by some kinds of transient processes related with hydrogen redistribution and outgassing. The binding energy of hydrogen to dislocation is determined to be about 0.19 eV.