Determination of the hydrogen fugacity during cathodic hydrogen charging of X65 D pipeline steel
Joshua Hoschke, Maximilian Roethig, Clotario V. Tapia‐Bastidas, Md Fahdul Wahab Chowdhury, Jeffrey Venezuela, Ying Shu, Evan Gray, Andrej Atrens
Abstract
Hydrogen embrittlement testing using cathodic hydrogen charging is directly relatable to structures containing gaseous hydrogen if the hydrogen fugacity is known. The hydrogen fugacity, f Hc , was evaluated by comparing the hydrogen concentration after cathodic charging with the hydrogen concentration in equilibrium with hydrogen gas: f Hc 0.5 = 6.11 i 0.5 + 10.9 for cathodic hydrogen charging X65 D in 0.10 M NaOH at a current density of i . The hydrogen concentration in equilibrium with gaseous hydrogen in X65 D, C Hg , was evaluated from literature values and hydrogen gas-phase permeation results: C Hg = 0.0062 f Hg 0.5 + 0.0355, where f Hg is the hydrogen gas fugacity. • Hydrogen embrittlement testing using cathodic charging can be related to structures containing gaseous hydrogen. • The hydrogen concentration in equilibrium with gaseous hydrogen, C Hg , was evaluated. • C Hg = 0.0062 f Hg 0.5 + 0.0355, where f Hg is the hydrogen gas fugacity. • The hydrogen fugacity was f Hc 0.5 = 6.11 i 0.5 + 10.9 for cathodic charging at a current density of i . • f Hc was evaluated by comparing the hydrogen concentration after cathodic charging with C Hg .