Thermo-ultrasound method for determining the damage of structural material

Abstract

The effect of plastic strain and temperature on the longitudinal and shear waves velocity of austenitic stainless steel 12Kh18N10T (analogue AISI 321) is investigated. Cryogenic corrosion-resistant austenitic steel 12Kh18N10T is interesting due to the fact, that during plastic deformation a martensitic phase is formed. The martensitic phase significantly changes the electromagnetic, elastic and strength properties of the entire material. The formation of a new phase in conjunction with the process of plastic deformation has a significant effect on the temperature dependence of the elastic wave velocity. As a result of the studies, numerical values of the temperature-velocity factor for longitudinal and shear ultrasonic waves in steel 12Kh18N10T were obtained. The relationship between changes of the magnetic phase and temperature-velocity factor is suggested; it can be used for determining the material damage by the ultrasound method.