Acoustic Birefringence Changes in the Base Metal and Heat Affected Zone of ASTM 1020 Steel under Plastic Deformation and Fatigue

This paper deals with metallographic studies and ultrasonic investigations of acoustic birefringence in the base metal heat affected zone welded specimens ASTM 1020 steel under uniaxial tension low-cycle fatigue. We examined microstructural changes on surface using optical microscope. It was found that development slip bands differs zone. The pulse echo method used for determination velocities shear waves. differences change were revealed. Acoustic to monotonously fatigue as well tension. For zone, during fatigue, non-monotonously up cycle ratio 0.3 decrease after 0.3. Based relationship between relative number loading cycles, or plasticity resource, birefringence, techniques proposed assessing damage.