Simultaneously enhancing strength and hydrogen embrittlement resistance of pure iron via gradient microstructure

• Published in: Corrosion science Vol. 218; p. 111134
• Main Authors: Li, Xinfeng, Wang, Canyu, Feng, Hui, Gu, Tang, Zhang, Jin, Zhang, Yong, Ren, Xuechong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2023
• Subjects: A. Pure iron; B. Pre-torsion; C. Gradient microstructure; C. Hydrogen embrittlement; C. Hydrogen embrittlement; C. Gradient microstructure; B. Pre-torsion; A. Pure iron
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2023.111134

Hydrogen embrittlement (HE) of gradient-structured pure iron was studied by slow strain rate tensile tests, microstructural analysis and time-of-flight secondary ion mass spectrometry. As pre-torsion angles increase from 0° to 1400°, yield strength of alloys monotonically increases, but the HE susceptibility first decreases and then increases, with optimal match of improved strength and HE-resistance for pre-torsioned sample at 400°. This correlates with gradient distributions of grain boundary and dislocation hydrogen traps. These results indicate that the construction of suitable gradient structure in alloys is a promising strategy to maximize the strength and HE-resistance synergy. •Gradient-structured pure iron is constructed by pre-torsion.•HE-resistance first increases and then decreases with increasing pre-torsion angle.•Simultaneous improvement of strength and HE-resistance for RFPT400 sample.•Strength prediction model of gradient-structured pure iron is proposed.