Abstract
Cleavage fracture can initiate by the cracking of second phase particles in metals. Understanding the size distribution, morphologies and compositions of initiating particles for a particular material is key to successful micromechanical modelling of cleavage. The second phase particles responsible for the fracture initiation in P141 CAC-S7, a reactor pressure vessel (RPV) weld metal from the EU-funded PERFORM 60 Multiscale Modelling Programme, have been identified and characterised in order to aid the development of a fracture model.Fractographic characterisation of CVN samples tested in the lower shelf region of the transition temperature curve was performed to identify cleavage initiation sites. The general microstructural characterisation of the material including fracture-initiating particles (inclusions) involved optical, laser scanning confocal and scanning electron microscopy combined with energy dispersive x-ray (EDX) microanalysis. The project used novel TEM-type specimens for microstructural analysis. The size and distribution of the inclusions present within the material were evaluated using image analysis techniques.The inclusions present throughout the weld were spherical, and predominantly manganese alumino-silicate with traces of titanium and magnesium. The size distribution of the inclusions responsible for the initiation of the cracks is presented together with comprehensive statistical analysis as well as how these results will be used in predictive modelling of cleavage fracture as part of the future work of PEFORM 60.
Original language | English |
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Title of host publication | host publication |
Place of Publication | Asheville, NC |
Publisher | American Nuclear Society |
Publication status | Published - 11 Aug 2013 |
Event | 16th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors - Asheville Duration: 11 Aug 2013 → 15 Aug 2013 |
Conference
Conference | 16th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors |
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City | Asheville |
Period | 11/08/13 → 15/08/13 |
Keywords
- Cleavage fracture
- second phase particles
- size distribution
- multiscale modelling