Segregation behaviour of phosphorus, manganese and carbon in boiler shell weld materials
thesisposted on 16.10.2018, 10:26 by Petra Maier
The work in this thesis has developed theoretical models to predict the microstructural behaviour of weld materials. Three different types of boiler shell weld materials from nuclear power plants have been investigated. The materials considered differ mainly in the manganese concentration and their microstructure after different temperature exposures during industrial use. Element segregation can be predicted according to the typical reactor conditions and therefore the influence of longer life times can be evaluated. Sufficient experimental data have been taken by application of advanced transmission electron microscopes which offer images of high quality. The application of a thermodynamic software package MTDATA to predict the free concentration of each element for model prediction has been. Phosphorus, of great interest because it causes embrittlement, is enhanced at the grain boundary and increases with operating temperature and life time. Its interaction with carbon and manganese is of interest. Site-competition between carbon, phosphorus and manganese has to be applied. These site competition model prediction results fit best to the experimental data. [Continues.]
British Nuclear Fuels Ltd.
- Aeronautical, Automotive, Chemical and Materials Engineering