Abstract
The microstructure generated in a low carbon steel under cyclic loading in air and a 40 MPa gaseous hydrogen environment has been compared as a function of distance from the crack tip. The presence of hydrogen resulted in the formation of a smaller and more equiaxed dislocation cell structure that extended further from the crack tip than the one generated in air. This enhancement and extension of the dislocation structure by hydrogen is consistent with it modifying the generation rate and mobility of dislocations as well as dislocation interactions. Qualitative assessment of the dislocation structure ahead of the crack tip found the stress ahead of the crack tip to vary linearly as ln(1/x), where x is the distance from the crack tip irrespective of the test environment. Hydrogen caused a shift to higher stresses, implying the critical damage level for crack propagation will be achieved more rapidly with a concomitant increase in the crack propagation rate.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 181-188 |
| Number of pages | 8 |
| Journal | Acta Materialia |
| Volume | 174 |
| DOIs | |
| State | Published - Aug 1 2019 |
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Keywords
- Electron microscopy
- Fatigue-crack growth
- Hydrogen embrittlement
- Low-carbon steel
- Plastic zone
- Stress magnitude
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys
Cite this
Assessment of the impact of hydrogen on the stress developed ahead of a fatigue crack. / Wang, Shuai; Nagao, Akihide; Sofronis, Petros; Robertson, Ian M.
In: Acta Materialia, Vol. 174, 01.08.2019, p. 181-188.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Assessment of the impact of hydrogen on the stress developed ahead of a fatigue crack
AU - Wang, Shuai
AU - Nagao, Akihide
AU - Sofronis, Petros
AU - Robertson, Ian M.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - The microstructure generated in a low carbon steel under cyclic loading in air and a 40 MPa gaseous hydrogen environment has been compared as a function of distance from the crack tip. The presence of hydrogen resulted in the formation of a smaller and more equiaxed dislocation cell structure that extended further from the crack tip than the one generated in air. This enhancement and extension of the dislocation structure by hydrogen is consistent with it modifying the generation rate and mobility of dislocations as well as dislocation interactions. Qualitative assessment of the dislocation structure ahead of the crack tip found the stress ahead of the crack tip to vary linearly as ln(1/x), where x is the distance from the crack tip irrespective of the test environment. Hydrogen caused a shift to higher stresses, implying the critical damage level for crack propagation will be achieved more rapidly with a concomitant increase in the crack propagation rate.
AB - The microstructure generated in a low carbon steel under cyclic loading in air and a 40 MPa gaseous hydrogen environment has been compared as a function of distance from the crack tip. The presence of hydrogen resulted in the formation of a smaller and more equiaxed dislocation cell structure that extended further from the crack tip than the one generated in air. This enhancement and extension of the dislocation structure by hydrogen is consistent with it modifying the generation rate and mobility of dislocations as well as dislocation interactions. Qualitative assessment of the dislocation structure ahead of the crack tip found the stress ahead of the crack tip to vary linearly as ln(1/x), where x is the distance from the crack tip irrespective of the test environment. Hydrogen caused a shift to higher stresses, implying the critical damage level for crack propagation will be achieved more rapidly with a concomitant increase in the crack propagation rate.
KW - Electron microscopy
KW - Fatigue-crack growth
KW - Hydrogen embrittlement
KW - Low-carbon steel
KW - Plastic zone
KW - Stress magnitude
UR - http://www.scopus.com/inward/record.url?scp=85066241989&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85066241989&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2019.05.028
DO - 10.1016/j.actamat.2019.05.028
M3 - Article
AN - SCOPUS:85066241989
VL - 174
SP - 181
EP - 188
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
ER -