Materials, Vol. 11, Pages 788: Effect of Cementite on the Hydrogen Diffusion/Trap Characteristics of 2.25Cr-1Mo-0.25V Steel with and without Annealing
Materials doi: 10.3390/ma11050788
Authors:
Yan Song
Zelin Han
Mengyu Chai
Bin Yang
Yilun Liu
Guangxu Cheng
Yun Li
Song Ai
Hydrogen embrittlement (HE) is a critical issue that affects the reliability of hydrogenation reactors. The hydrogen diffusivity/trap characteristics of 2.25Cr-1Mo-0.25V steel are important parameters mainly used to study the HE mechanism of steel alloys. In this work, the hydrogen diffusivity/trap characteristics of heat-treated (annealed) and untreated 2.25Cr-1Mo-0.25V steel were studied using an electrochemical permeation method. The microstructures of both 2.25Cr-1Mo-0.25V steels were investigated by metallurgical microscopy. The effect of cementite on the hydrogen diffusivity/trap mechanisms was studied using thermodynamics-based and Lennard–Jones potential theories. The results revealed that the cementite located at the grain boundaries and at the interfaces of lath ferrite served as a kind of hydrogen trap (i.e., an irreversible hydrogen trap). In addition, hydrogen was transported from ferrite to cementite via up-hill diffusion, thereby supporting the hypothesis of cementite acting as a hydrogen trap.
Authors: |
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Song, Yan ; Han, Zelin ; Chai, Mengyu ; Yang, Bin ; Liu, Yilun ; Cheng, Guangxu ; Li, Yun ; Ai, Song |
Journal: |
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Materials
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Volume: |
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11 |
edition: |
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5 |
Year: |
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2018 |
Pages: |
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788 |
DOI: |
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10.3390/ma11050788
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Publication date: |
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12-May-2018 |