Residual Strength, Microhardness, and Acoustic Properties of Low-Carbon Steel after Cyclic Loading

The residual strength of low-carbon steel after cyclic loading before different numbers of cycles at various stress amplitudes is estimated. The correlation of the residual strength with the damage, microhardness of steel, and its acoustic properties including the characteristics of acoustic emission, propagation velocity, and attenuation coefficient of the ultrasound is specified. New criteria of diagnostics of the material state are proposed to reflect the degree of damage during cyclic loading.