Estimation of plasticity margin in stainless steel by the thermo-ultrasonic method

The effect of plastic strain and temperature on the longitudinal and shear wave velocity of the 12Kh18N10T austenitic stainless steel (analogous to AISI 321) is investigated. The studies have shown that the relation between the ultrasonic wave velocity and temperature for different plastic strains is well approximated by a linear dependence. As a result of the studies, numerical values of the temperature-velocity factor for longitudinal and shear ultrasonic waves in the 12Kh18N10T steel were obtained. The relationship between plasticity margin and the temperature-velocity factor is proposed, which can be used for the determination of material damage by the ultrasound method.