As oil and gas (O&G) production moves towards developing more challenging fields, including high pressure/high temperature wells, selection of corrosion resistant alloys (CRAs), such as stainless steels and nickel alloys as solid products, linings or cladding on to substrate steel is becoming more common.
While CRAs usually possess a passive oxide layer that imparts good resistance to general (uniform) corrosion, these alloys can suffer from localised forms of corrosion, such as pitting, through breakdown of the passive film.
Pitting of CRAs initiates at local heterogeneities, such as inclusions, second/third phases, flaws or sites of mechanical damage on the passive surface. After initiation, pits can either repassivate and cease growing (i.e. metastable pits) or grow to stable pits, depending on many factors, including the alloy condition and the environment. Defining the aggressivity of an environment is difficult and establishing causal relationships is challenging. It follows that there is a fundamental requirement to identify what types of heterogeneities, for a given set of field situations, lead to the establishment of localised extreme environmental conditions and electrochemical activity that results in stable pitting.
The end goal of this PhD project is to use electrochemical corrosion techniques to identify material ‘flaws’ (physical, compositional, metallurgical or chemical non-uniformities that exist naturally on component surfaces) and environmental preconditions (at the macroscale and microscale) that lead to nucleation and propagation of stable pits.
A number of fully-funded PhD scholarships are available for suitable candidates with a strong interest in fundamental and applied research in the area of structural integrity. Scholarships cover an amount to £16,000 per annum for 3 years, Home/EU tuition fees and support for research. Overseas applicants are welcomed, with total funding capped at £20k/year.
Candidates should have a relevant degree at 2.1 minimum, or an equivalent overseas degree in mechanical, Electrical/Electronics or Civil/Structural Engineering, Material Science, Metallurgy or Physics. Candidates with suitable work experience and strong capacity in numerical modelling and experimental skills are particularly welcome to apply. Overseas applicants should also submit IELTS results (minimum 6.5) if applicable.
NSIRC will be a state-of-the-art postgraduate engineering facility established and managed by structural integrity specialist TWI, working closely with lead academic partner Brunel University, the universities of Cambridge, Manchester, Loughborough, Birmingham, Leicester and a number of leading industrial partners. NSIRC aims to deliver cutting edge research and highly qualified personnel to its key industrial partners.
For more information about The National Structural Integrity Research Centre, visit www.nsirc.co.uk
Please direct general enquiries to: [email protected]