Effect of microstructure of low carbon steels on ultrasonic attenuation

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 47; no. 3; pp. 620 - 629
• Main Authors: Ahn, B, Lee, S S
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.05.2000; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Attenuation measurement; Carbon content; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Ferrite; Ferrites; Frequency measurement; Grain size; Iron; Low carbon steels; Materials science; Materials testing; Microstructure; Nondestructive testing: ultrasonic testing, photoacoustic testing; Normalizing; Physics; Scattering; Steel; Steels; Temperature distribution; Ultrasonic attenuation; Ultrasonic variables measurement; Grain size; Ferrite; Wave attenuation; Carbon content; Low carbon steel; Austenite; Ultrasonic waves; Eutectoid steel; Iron; Microstructure; Carbon
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/58.842049

The ultrasonic attenuation in low carbon steel with 0.04 wt% C to 0.80 wt% C was measured over a frequency range of 5 to 15 MHz, and the effects of the carbon content and normalizing temperature were analyzed. In pure iron, the attenuation is determined from the average grain size, which increases as the normalizing temperature increases; there is a noticeable effect caused by a few large grains. In the case of the hypoeutectoid steels, the proeutectoid ferrite grain, the size of which depends on prior austenite grain size, acts as the main scatterer. The prior austenite grain size increases as the carbon content decreases and the normalizing temperature increases. The colony is responsible for scattering in the eutectoid steel; scattering by pearlite is greater than that by ferrite.