Attenuation of the Ultrasonic Waves in Metals. II : Stainless Steel

Ultrasonic attenuation coefficients of stainless steel with various grain sizes were measured by pulse method at the frequencies ranging from 0.5 to 6 Mc/s. The stainless steel used was of austenite structure containing about 19 per cent of chromium and 10 per cent of nickel. It was found that the attenuation coefficient increased remarkably with the frequency, and that the increase was more rapidly with increasing size of crystal grains. The nature of such an attenuation behaviour was explained by assuming that the travelling ultrasonic waves are scattered by the austenite crystal grains in accordance with the Rayleigh\u27s law