Effect of Grain Size and Preferred Crystal Texture on Acoustic Properties of 304 Stainless Steel
Several acoustic properties have been measured in an annealed round rolled bar of type 304 stainless steel. These properties were observed to depend upon both microstructure and the non-random crystal texture of this single phase, polycrystalline, face-centered cubic alloy. All measurements were made with longitudinal waves propagating parallel to the bar axis. The acoustic velocity was observed to be 0.3% higher near the outer surface than along the center of the bar, consistent with a stronger  texture in the outer fibers than at the center. The attenuation coefficient at the center was twice as large as at the outer surface. The measured difference in grain size at the center and surface was consistent with the observed attenuation difference. The acousto-elastic coefficient measured for a uniaxial tension stress applied along a bar diameter was at least 20% higher at the bar center than at its outer surface.