Array imaging of inhomogeneous steel welds by measurement of weld material maps

This proposal seeks funding for a three year research programme into the radical improvement of defect detection and sizing in inhomogeneous welds, such as austenitic steel welds. Welds of high temperature steels such as austenitic steels and Inconel have stiffness properties which are typically both anisotropic and inhomogeneous, so that ultrasonic wave rays tend to deviate and scatter. This results in inaccurate interpretation of defect sizes. Knowledge of weld maps which describe how the material properties vary throughout the weld, applied to wave propagation models, would allow array images to be corrected to compensate for the deviations of the rays. Work at Manchester University will investigate how weld maps can be constructed, using sectioning, experimental measurements, and materials modelling. Work at Imperial College will investigate the use of ultrasonic array measurements in order to measure such maps non-destructively. The findings will be combined to create a procedure to correct array images to enable accurate sizing of the defects. The work will be done in collaboration with two industrial companies who will both provide realistic weld specimens.The proposal is being submitted within the UK Research Centre in NDE (RCNDE) to the targeted research programme, the funding for which is earmarked by EPSRC for industrially driven research.