Influence of steel heat treatment on ultrasonic absorption measured by laser ultrasonics

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2004-04, Vol.370 (1), p.401-406
• Main Authors: Lamouche, Guy, Bolognini, Stéphane, Kruger, Silvio E
• Format: Article
• Language: English
• Subjects: Applied sciences; Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Internal friction; Laser ultrasonics; Materials science; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Other mechanical properties; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Reverberation technique; Ultrasound absorption
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2003.07.019

Laser ultrasonics is combined with the reverberation technique to measure ultrasound absorption during thermal cycles applied to medium-carbon steel samples. During heating to the austenitic phase, a small Snoek peak is observed around 360 °C at 10 MHz along with a signature of the ferromagnetic to paramagnetic transition near 768 °C. Upon cooling, the behavior of the internal friction is much different from that of heating: reduced high-temperature absorption, delayed phase transition, smaller magnetoelastic contribution and stronger Snoek peak are observed. The austenitizing temperature is found to have primary importance on the internal friction behavior during cooling. These measurements show that ultrasound absorption measurements using laser ultrasonics could serve as a basis for a technique to characterize the microstructure evolution of steel in various temperature ranges.