The Effect of Water Chemistry on the Stress Corrosion Cracking Initiation of Nickel Based Alloys (Sponsor: Hitachi; FULLY FUNDED)
This project is available via the EPSRC Centre for Doctoral Training in Materials for Demanding Environments (CDT in M4DE), is sponsored by Hitachi and will commence October 2017.
Materials used within light water reactors (LWRs) must be resistant to demanding environmental conditions during a substantial operational period of circa. 60 years. In boiling water reactors (BWRs) this includes elevated temperatures (up to 287°C) and high pressures (up to 7.2 MPa). Stainless steels and nickel based alloys that have excellent strength properties and high corrosion resistance have been developed for use in BWR recirculation piping and reactor internals. However, despite their high durability, in such extreme conditions they can be susceptible to stress corrosion cracking (SCC).
New build ABWR plants will be designed to have a longer operational life than previous designs, with emphasis placed on optimising the Plant Availability Factor by reducing the downtime required for maintenance. By increasing confidence in material performance the need for maintenance can be reduced; thus developing means to suppress & counter SCC remains a key issue for managing plants.
Significant work has been undertaken on SCC propagation for both austenitic and Ni base alloys over a wide range of environments that span from BWR water (oxygenated) to PWR (hydrogenated) and HWC BWR (hydrogen and oxygen water chemistry), with a variety of water chemistry in an attempt to understand and mitigate the impact of SCC. This project will focus on understanding the implication of water chemistry on the initiation stages of SCC of Alloy 82 and 52, a filler metal extensively used in Light Water Reactors weldments. The project will use the University of Manchester and Materials Performance Centre extensive high temperature testing capability to simulate the nuclear water environment. SCC initiation will be induced in the samples that are oxidized at constant strain rate, or subjected to other types of accelerated testing, and subsequently analysed with the advanced analytical electron microscopes at the university in order to obtain a mechanistic understanding of the controlling mechanism of environmental degradation. The project will benefit from the professional guidance and the significant expertise of Hitachi Research Laboratory in Japan as well as the possibility for the student to carry out an industrial placement at Hitachi’s laboratories.
Funding covers tuition fees and annual maintenance payments of £17,000. Students with a first class/2.1 degree (or equivalent) in Engineering, Materials Science, Metallurgy, Physics, Chemistry or another aligned science or engineering subject are encouraged to apply. Applications will be reviewed as they are received until a candidate is selected; therefore candidates are encouraged to apply early.
Funding is available to UK candidates only.