Characterization of Grain Size and Yield Strength in AISI 301 Stainless Steel Using Ultrasonic Attenuation Measurements

AISI 301 stainless steel samples were annealed over the temperature range of 800-1200A degrees C for 60 minutes to produce different grain sizes. These samples were characterized by ultrasonic immersion technique, tensile test, and optical microscopy. The attenuation of ultrasonic waves measured at a frequency of 20 MHz showed a good correlation with average grain size, hardness, and yield strength of AISI 301 stainless steel samples. A new equation was derived for calculation of yield strength on the basis of ultrasonic wave attenuation and Hall-Petch relation.