The influence of hydrogen on the mechanical and fracture properties of some martensitic advanced high strength steels studied using the linearly increasing stress test

• Published in: Corrosion science Vol. 99; pp. 98 - 117
• Main Authors: Venezuela, Jeffrey, Liu, Qinglong, Zhang, Mingxing, Zhou, Qingjun, Atrens, Andrej
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2015
• Subjects: A. Steel; B. SEM; C. Hydrogen embrittlement; B. SEM; C. Hydrogen embrittlement; A. Steel
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2015.06.038

•Hydrogen influence increased with strength, charging potential, and decreasing applied stress rate.•The hydrogen influence was manifest by reduced strength, changed fracture and decreased ductility.•The decrease in yield stress was attributed to solid solution softening by hydrogen.•Hydrogen caused a change at the fracture stress when the specimen was mechanically unstable.•The fracture changed from ductile cup-and-cone fracture to macroscopically brittle shear fracture.
The influence of hydrogen on the mechanical and fracture properties of four martensitic advanced high strength steels was studied using the linearly increasing stress test and electrochemical hydrogen charging. The hydrogen influence increased with steel strength, decreasing charging potential, and decreasing applied stress rate. Increased hydrogen influence was manifest in (i) the decreased yield stress attributed to solid solution softening by hydrogen and (ii) the reduced macroscopic ductility, and by the change from ductile cup-and-cone fracture to macroscopically brittle shear fracture, attributed to a dynamic interaction of hydrogen with the dislocation substructure somewhat similar to the HELP mechanism.