Abstract
The possibility of obtaining a quantitative relation between acoustic emission (AE) signal amplitudes and arrested cleavage microcrack sizes in the partially transformed coarse grained heat affected zone of a structural steels is explored. Interrupted fracture mechanics tests are performed, and the size of measured arrested cleavage microcracks are compared with recoded AE signal amplitudes. It is shown that the experimentally measured relationship between the arrested microcrack size and AE amplitude closely follows a theoretical relation derived by Lysak (1996). The results may provide quantitative data as input to further development of micromechanically based cleavage fracture models for steels.