Failure of power station steel components can have severe economic impacts; an unplanned shutdown can cost in the order of ￡1M per day per power station, and also presents significant risk to life and the environment. Currently components are inspected during shut down periods and to this point, no in-situ technique has been developed to monitor changes in microstructure of in-service power station steel components at elevated temperatures. Electromagnetic inspection techniques have the potential to provide information on microstructural changes in power station steels in-situ in hostile environments. Tests have been carried out on samples taken from power station pipes in different states of degradation using a lab-based closed magnetic circuit measurement system (machined samples) and a field deployable device (open samples) developed at the University of Manchester. Magnetic hysteresis and incremental permeability measurements have been carried out and correlations established between electromagnetic properties and material properties such as hardness and dislocation density. This will allow the quantification of degradation in power station steels both in-situ and at elevated temperatures; and could, therefore, lead to considerable savings in terms of down-time used for component inspection.
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