Acoustic emission behaviour during cyclic deformation of austenitic stainless steel

In order to study the application of the acoustic emission techniques to the method of materials evaluation, acoustic emission peak height, amplitude distribution and event counts were investigated in austenitic stainless steel during the constant stress amplitude cyclic deformation. The large burst type of acoustic emission was observed during the stress reversal from the compression cycle and generally the acoustic emission activity, in terms of the acoustic emission events per stress cycle, increased markedly with increasing testing temperature. The results suggest that the source of observed acoustic emission was due to both the reyielding of the crack tip, and also to the unsticking of partially rewelded area of the crack during the stress reversal. (auth.)