Relationship Between the Parameters of Acoustic Structural Noise and the Mechanical Properties of Structural Steels

Abstract

We perform the comparative analysis of the parameters of acoustic structural noise in specimens of 40G structural steel with the use of ultrasonic flaw detectors with phased arrays. It is shown that the parameter of integral density of B-scan images most completely reproduces the variations of energy of acoustic vibrations reflected from the microstructural inhomogeneities (grain-size inhomogeneity, changes in the ratios of the phase components). The relationship between the parameter of integral density of the image of acoustic structural noise Ro and the mechanical properties of 40G steel is established. We propose an improvement of the well-known method of determination of the yield limit σy of steels according to the results of measurements of the HB hardness. To do this, we added the parameter Ro to the equation used for computations. As a result, we deduced a new equation of the form σy = f (Ro, HB) for the yield strength of 40G steel within the specified range of its values.