INFLUENCE OF SINGLE-AXIS TENSION OF 09G2S STEEL SAMPLES AFTER DIFFERENT THERMAL TREATMENT ON ACOUSTIC STRUCTURAL NOISES

Abstract

In the development of ultrasound structurescopy the authors have offered a new approach to the assessment of metal structure by ratio value of amplitude of a middle level of acoustic structural noises to the amplitude of «appear» of Rayleigh waves. The level change of structural noises in 09G2S steel at single-axis tension has been researched. The influence of mechanical stresses, as well as structural metal states on the level of structural noises has been shown. The authors have determined the presence of relation between the parameters of acoustic structural noises and structural state of 09G2S steel. Also the authors revealed the regularity of sharp decrease of the level of structural noises when metal reaches the yield point. It has been experimentally confirmed that the sharp drop of the level of structural noises (the inflection point), when reaching the yield point, confirms a high sensitivity of the method to the changes of metal structure. This fact allows recommending the measurement method of acoustic structural noises to reveal the preparatory stage of the process, connected with the accumulation of the damageability in metal, namely, the stage of accumulation of microimperfection.