Inference of mechanical properties in heat treated steel from ultrasonic attenuation and velocity measurements.

Abstract

Round bar tension test, Charpy V impact test and static 3-point bending test as well as ultrasonic attenuation and wave velocity measurements are made by using carbon steel heat treated with various conditions. Those tests are carried out for the purpose of establishing the nondestructive methods for material property characterization. Correlations between results of material tests and ultrasonic attenuation or wave velocity are examined.Relationships between yield strength, ultimate strength or elongation percentage and attenuation coefficient are represented by smooth curves. Yield strength as well as ultimate strength decreases and elongation percentage increases with increasing attenuation coefficient. Relationship between Charpy V notch impact energy absorption in the upper shelf region and wave velocity is represented approximately by a straight line. Upper shelf energy absorption increases with increasing velocity. Relationship between critical COD and attenuation coefficient is represented roughly by a straight line. Critical COD increases with increasing attenuation coefficient. Using the results above mentioned, mechanical properties such as strength, elongation and fracture toughness can be estimated nondestructively from ultrasonic attenuation or wave velocity.