Effect of electrochemical charging on the hydrogen embrittlement susceptibility of a low-alloyed tempered martensitic steel submitted to high internal pressure

• Published in: International journal of hydrogen energy Vol. 63; pp. 657 - 667
• Main Authors: Peral, L.B., Díaz, A., Colombo, C., Alegre, J., Cuesta, I.I.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 18.04.2024
• Subjects: Cathodic hydrogen precharge; Electrochemical permeation; Fracture micromechanisms; High internal pressure; Hydrogen embrittlement; Cathodic hydrogen precharge; Fracture micromechanisms; Electrochemical permeation; Hydrogen embrittlement; High internal pressure
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2024.03.034

The influence of hydrogen on the mechanical behavior of a quenched and tempered 42CrMo4 steel has been evaluated by means of high internal pressure fracture tests carried out on hydrogen precharged notched cylindrical specimens. The notched cylindrical specimens were precharged for 3 h time with 1.2 mA/cm2 in two different aqueous media: 1 M H2SO4 added with 0.25 g/l As2O3 and 3.5% of NaCl solution. Hydraulic fracture tests were performed at different ramps of pressure: 7000, 220, 80, 60 and 30 MPa/h, respectively. Hydrogen damage was more marked when the acid aqueous medium (1 M H2SO4 + 0.25 g/l As2O3) was employed. In this case, a higher hydrogen concentration was introduced, leading to hydrogen decohesion micromechanisms (HEDE) near the notched region, especially when tests were performed at 60 MPa/h. Hydrogen embrittlement susceptibility is discussed in terms of the microstructural singularities and the operative fracture micromechanisms observed in each case. •Hydrogen embrittlement is studied by high internal pressure hydraulic fracture tests.•Hydrogen uptake and desorption were studied by hot extraction and electrochemical permeation.•Hydrogen embrittlement is enhanced when specimens were precharged in an acid medium.•In the acid medium, H-induced decohesion micromechanims were noted at 60 MPa/h.•Fracture micromechanism was always ductile when specimens were precharged in 3.5% NaCl.