In collaboration with Amsted Rail, Inc., we have developed methods to improve the production of railcar bearings and wheels. Impurities within steel components can prove detrimental to their performance because they can act as stress concentrations that lead to crack initiations sites. These can potentially lead to catastrophic results.
We have developed ultrasonic inspection protocols that are currently used by Amsted Rail – Brenco to improve their steel procurement process and to ensure their products are free of nonmetallic inclusions.
The bearing research has resulted in ultrasonic methods that identify subsurface inclusions that have been shown to lead to spalling during simulated service life testing (a collaboration with the University of Texas – Pan America).
Figures: the ultrasonic C-scan identifies a flaw (F) that later develops into a spall on the race of a railcar bearing.
The wheel research utilized diffuse ultrasonic backscatter to quantify the pearlite microstructure that is created during the quenching process of the wheel tread surface.
Figures: the cross section of the quenched wheel shown was scanned at various positions from the tread surface. The amplitude of the diffuse ultrasonic backscatter increases from the tread surface as the fine pearlite transitions to a coarser microstructure. Results at 10 MHz (green) and 15 MHz (red) are shown.