Can ultrasound attenuation measurement be used to characterise grain statistics in castings?

Industrial inspection protocols are qualified using mock-ups manufactured according to the same procedure as plant part. For coarse-grained castings, known for their low inspectability, relying on becomes particularly challenging owing variability of grain properties among components. Consequently, there is a keen interest in capability verify whether size component under test matches qualification specification in-situ. This paper investigates potential an attenuation measurement assessing ultrasonic inspectability components procedures practical setting. The experimental part study focuses industrial Inconel 600 mock-up with spatially varying attenuation, measured across entire sample immersion tank. Three zones distinctly different attenuations were examined metallography, which allowed calculating classical histograms and two-point correlation functions. one zones, we synthesised microstructure statistical numerically simulated propagation ultrasound grain-scale finite element model. results showed good agreement experiment, lead several suggestions reasons discrepancy, statistics being most likely. A parametric study, followed, depicted effect mean standard deviation-to-mean ratio log-normal distribution its frequency dependence. Most notably, demonstrated non-uniqueness relationship between parameters attenuation. We suggested that length calculated from single exponential fit function more robust metric describing this context, can be obtained lengths estimated second-order approximation model three studied yielded acceptable accuracy. concluded could replace average settings, it retains information than allows linking measurements established theoretical models demonstrates.