Development of an Electrochemical Procedure for Monitoring Hydrogen Sorption/Desorption in Steel. Issue 13 (30th September 2017)

• Record Type: Journal Article
• Authors: Ozdirik, Berk; Baert, Kitty; Depover, Tom; Vereecken, Jean; Verbeken, Kim; Terryn, Herman; De Graeve, Iris
• Is Part Of: Journal of the Electrochemical Society. Volume 164:Issue 13(2017)
• Page Start: C747
• Page End: C757
• Publication Date: 2017-09-30
• Subjects: hydrogen absorption -- Hydrogen embrittlement -- thiourea; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.0521713jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Hydrogen embrittlement leads to mechanical degradation of metals. Hence, hydrogen sorption/desorption properties of metals need to be characterized. An electrochemical procedure based on cyclic voltammetry (CV) and potentiostatic polarization is elaborated on plain-carbon steel. The procedure consists of first two consecutive CV cycles (pretreatment and reference CV), followed by cathodic H-charging, and subsequent CV scans to study and quantify the H-sorption/desorption. Best practice in this procedure is to perform all steps consecutively without interruption or sample manipulations between steps to avoid spontaneous H-loss. The H-related interaction with the steel is clearly identified in the CV and can be differentiated from the electrolyte contribution coming from thiourea. The study confirms the role of thiourea as H-recombination poison in alkaline solution, and also demonstrates that it contributes to the CV response. Additionally, various charging times are investigated to study the time to H-saturation, and also the scan rate during the CV procedure is varied to study time-related phenomena. Dedicated discharging experiments were included in the study to complement the CV data, giving additional insights in the H-steel interaction. Moreover, hydrogen related findings are successfully verified by using a complimentary method, i.e. hot extraction. The better understanding of the peaks in the CV and the continuous procedure result in a reliable methodology to characterize the H-sorption/desorption in steel.