Nondestructive characterization of microstructures and determination of elastic properties in plain carbon steel using ultrasonic measurements

This paper presents a reliable and fast nondestructive characterization of microstructural and elastic properties of plain carbon steel, based on ultrasonic measurements for ultrasonic velocity and attenuation. Microstructures considered are: ferrite, pearlite, ferrite–pearlite and martensite. Ultrasonic velocities considered longitudinal and transverse waves and modulus of elasticity and modulus of shear were determined by correlations between them. In carbon steels, a lower value of ultrasonic velocity was observed for the martensite in relation to the other microstructures, while the opposite was observed in terms of ultrasonic attenuation. The results show that the use of ultrasonic measurements to obtain ultrasonic velocities and attenuations, in order to correlate them with the involved microstructures, as well as to determine the modulus of elasticity and modulus of shear, is very fast and reliable, permitting the characterization of nondestructive microstructural and elastic properties.