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Hydrogen Permeation in X65 Steel under Cyclic Loading
Marina Cabrini1,2, Luigi Coppola1,2,3, Sergio Lorenzi1,2,3
1Department of Engineering and Applied Sciences, University of Bergamo, 24129 Bergamo, Italy.
Materials (Basel, Switzerland)
|May 21, 2020
Summary
This study reveals that cyclic tensile stress significantly impacts hydrogen embrittlement in low-alloyed steels. Exceeding yield strength increases hydrogen trapping, reducing diffusion and accelerating material degradation.
Area of Science:
- Materials Science
- Metallurgy
- Corrosion Engineering
Background:
- Hydrogen embrittlement is a critical failure mechanism in steels.
- Understanding hydrogen diffusion and trapping is crucial for material integrity.
Purpose of the Study:
- To investigate the hydrogen embrittlement mechanism in quenched and tempered low-alloyed steels.
- To analyze the effect of cyclic loading on hydrogen diffusion and trapping.
Main Methods:
- Experimental analysis of hydrogen diffusion under cyclic loading.
- Fitting permeation curves using literature models.
- Evaluation of reversible and irreversible trapping mechanisms.
Main Results:
- Cyclic loading above tensile yield stress shifts permeation curves, indicating increased hydrogen trapping.
- Plastic strain leads to irreversible trapping, reducing diffusible hydrogen.
- Exceeding yield strength significantly reduces the diffusion coefficient and increases trap density.
Conclusions:
- Tensile stress above yield strength enhances hydrogen entrapment phenomena in low-alloyed steels.
- Cyclic loading amplifies hydrogen trapping, impacting material performance and durability.
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