Nondestructive evaluation of intergranular attack on material surface using leaky surface acoustic wave method. Pt.1. Application of immersion critical angle technique

Leaky surface acoustic wave (LSAW) is generated by the immersion technique when the incident angle is equal to the critical angle of LSAW. The signal obtained by the scattered wave received from a test surface is maximized under the above condition. The objective of this study is to apply this technique (critical angle technique) to detect and evaluate intergranular attack (IGA) of sensitized stainless steel (SUS304). The investigations showed that the velocity of LSAW decreases with increasing depth of IGA. Therefore, it can be suggested that the critical angle technique has the potential capability to evaluate the depth of IGA quantitatively. (author)