Ultrasonic attenuation measurements up to a frequency of 30 MHz have been made on a low-carbon steel. The microstructure was controlled to produce a series of specimens with varying ferrite grain size. Analysis of the attenuation data was not possible using a simple Rayleigh scattering model and the mean grain size. It was concluded that the grain size distribution is an important factor in determining the attenuation and that a relatively small number of large grains can dominate the scattering processes.
