抄録
This paper developed a method for detecting of inclusion in steel sheet with thickness about 230um, using Leaky Surface Acoustic wave (LSAW). A special lens which have hollow in its center, it is called DH lens, was applied in this detection. Results showed that the ultrasonic sensor with low frequency (20MHz) can detect the non-metallic inclusions more clearly than the conventional method with high frequency(100MHz). The practice showed that DH lens sensor can detect non-metallic inclusions in higher S/N ratio than conventional sensor. The detected result was also verified in SEM(Scanning Electron Microscope).
