title: Anomalous ultrasonic attenuation in ferritic steels at elevated temperatures.
abstract: An unexpected peak in attenuation has been observed at ∼800°C when heating low carbon steels in a laser-ultrasonic instrument. An explanation is given in terms of enhanced crystalline anisotropy with increasing temperature in the bcc ferrite range combined with subsequent transformation to austenite at still higher temperatures. An analysis based on theoretical models of attenuation in the Rayleigh regime is in good agreement with the experimental observations.
authors.affiliation: Swerea KIMAB, Box 7047, SE-164 07 Kista, Sweden. Electronic address: bevis.hutchinson@swerea.se.
authors.forename: Bevis
authors.initials: B
authors.lastname: Hutchinson
authors.affiliation: Swerea KIMAB, Box 7047, SE-164 07 Kista, Sweden. Electronic address: peter.m.lundin@swerea.se.
authors.forename: Peter
authors.initials: P
authors.lastname: Lundin
authors.affiliation: Swerea KIMAB, Box 7047, SE-164 07 Kista, Sweden. Electronic address: eva.lindh@swerea.se.
authors.forename: Eva
authors.initials: E
authors.lastname: Lindh-Ulmgren
authors.affiliation: National Research Council Canada, 75, de Mortagne, Boucherville, QC J4B 6Y4, Canada. Electronic address: daniel.levesque@cnrc-nrc.gc.ca.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lévesque
keywords: Anisotropy; Attenuation; Laser-ultrasonics; Phase transformation; Steel