Investigation of grain sizes of steels by ultrasonic method

Grain size that related directly to the mechanical properties of metals also influences ultrasonic waves that travel into materials. In this study, effect of grain size on attenuation and velocity of scattering ultrasonic waves in AISI type 1020, Ship Plate, St37 and 7-Mn-6 steels which are some types plain carbon steels, have been investigated. The specimens were heat treated to obtain variations in grain sizes. Ultrasonic parameters were measured using pulse-echo method and correlated with grain sizes measured with ASTM E112-88 standard from optical photomicrographs of specimens.In this study, applicability of ultrasonic grain size determination in AISI type 1020, Ship Plate, St37 and 7-Mn-6 steels and available frequency are tested.It is aimed to set up a non-destructive material testing system for ultrasonic measurements.