Nondestructive evaluation of material properties with EMAT (formability in cold rolled steel sheets and residual stress in railroad wheel)

Ultrasonic techniques using an EMAT (electromagnetic acoustic transducer) for evaluating material properties were developed. Two items are described. One is the evaluation of the formability in cold-rolled steel sheets by using the S/sub 0/-mode plate-wave EMAT. The other is the measurement by the stress in the rim of railroad wheels by using two polarized SH-waves EMATs. The experimental results obtained in these techniques agree with theoretical predictions, and the techniques are useful for monitoring the material properties.<
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