Hydrogen Entry in Crevice Region: Evaluation by Hydrogen Permeation Technique

Abstract

Pure iron exposed to acetate buffer showed both metal dissolution and hydrogen evolution inside the crevice region. Potential drop occurred inside the crevice led to both active dissolution and cathodic reactions. Hydrogen ingress into the specimen was monitored on the rear side using electrochemical hydrogen permeation technique. The results showed that magnitude of hydrogen entered inside the crevice could be detected by the permeation technique. Change in the applied potential significantly influenced the amount of permeated hydrogen. The results are correlated potential drop occurred inside the crevice, which influenced the magnitude of diffusible hydrogen.

Evaluation of Delayed Fracture Property of High Strength Bolt Steels

“…When delayed fracture occurs at a part of thread where is covered with a nut, one of the possible causes of hydrogen entry is crevice corrosion. [67][68][69] Further understanding of hydrogen entry behavior into actual high strength bolts in service is required in detail. However, the susceptibility of high strength steels could be appropriately evaluated using CCT and SSRT.…”