Assessment of fatigue failure of square-section profile tube made of chromium-nickel stainless 12Kh18N10T steel by ultrasonic method

Fatigue failure of a square-section profile tube made of chromium-nickel stainless 12Kh18N10T steel during a three-point bending test are studied. Acoustic and elastic characteristics in the area of maximum stresses are determined based on the results of ultrasonic measurements. The content of strain induced martensite is determined by the eddy current method. A metallographic analysis of the undamaged and damaged sections of the material is carried out. The possibility of using the Poisson’s ratio and the acoustic birefringence to estimate the residual life of the material of a typical structural element at the stage of accumulation of microdamage, before the formation of a macrocrack, is shown.