Investigating electrochemical charging conditions equivalent to hydrogen gas exposure of X65 pipeline steel

Abstract

In this study, we systematically investigate electrochemical hydrogen charging conditions equivalent to hydrogen gas pressures relevant for hydrogen transportation in X65 pipeline steel. By performing hydrogen gas permeation, a relationship for Sieverts' law was established, which was used in combination with electrochemical hydrogen permeation to determine the equivalent hydrogen pressure. The results revealed that cathodic protection simulated condition at –1050 mVAg/AgCl was equivalent to a hydrogen pressure of 12.3 bar. The addition of thiourea, a hydrogen recombination poison, and changing the applied potential in the cathodic direction increased the equivalent hydrogen pressure. In this way, an electrochemical charging condition equivalent to a potential hydrogen gas pressure for hydrogen transportation (200 bar) was determined.

Hydrogen Embrittlement as a Conspicuous Material Challenge─Comprehensive Review and Future Directions

“…Permeation tests provide a means to determine f H 2 eq by comparing the permeability coefficients obtained with the two charging methods; these tests can also be applied to determine f H 2 eq directly based on eq in conjunction with thermodynamic calculations . Recently, a correlation between gaseous and electrochemical charging on a X65 pipeline steel was established using this methodology. , Alternatively, the equivalent H fugacity can be determined with TDS by comparing the H concentration in gas-charged and electrochemically charged samples. , …”