EPSRC Reference: |
GR/L84988/01 |
Title: |
A MODEL FOR HYDROGEN - ASSISTED STABLE CRACK GROWTH IN HIGH STRENGTH STEELS |
Principal Investigator: |
Marrow, Professor J |
Other Investigators: |
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Researcher Co-Investigators: |
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Project Partners: |
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Department: |
Manchester Materials Science Centre |
Organisation: |
UMIST |
Scheme: |
Standard Research (Pre-FEC) |
Starts: |
01 September 1998 |
Ends: |
31 January 2002 |
Value (£): |
181,202
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EPSRC Research Topic Classifications: |
Materials Characterisation |
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EPSRC Industrial Sector Classifications: |
No relevance to Underpinning Sectors |
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Related Grants: |
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Panel History: |
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Summary on Grant Application Form |
A model has been proposed for the effects of yield strength, temperature and hydrogen concentration on hydrogen-assisted stable crack growth in steel. The growth rate is controlled by the size of the discontinuous crack growth increment and dislocation trapping of hydrogen diffusing through the crack tip plastic zone. Increasing yield strength decreases the plastic zone size and increases the crack growth rate. Good agreement with published growth rate data has been found. Development of the model, which may be applicable to other materials, requires both high resolution fractographic observations and crack growth rate data for the effects of yield strength, temperature and hydrogen pressure in well characterised steel microstructures.These measurements will be performed in a quenched and tempered high strength steel and a maraging steel, to confirm the predicted insensitivity of the crack growth rate to microstructure, and to identify the boundaries within which the model is applicable. The distribution of dislocation density and dislocation structure around the crack tip will be measured using transmission electron microscopy. High resolution microscopy, including scanning probe microscopy, will be used to study the fracture mechanism. Funds are requested for an environmental testing system and a post-doctoral research assistant with technical support.
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Key Findings |
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Potential use in non-academic contexts |
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Impacts |
Description |
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Summary |
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Date Materialised |
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Sectors submitted by the Researcher |
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Project URL: |
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Further Information: |
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Organisation Website: |
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