ACOUSTIC-EMISSION DURING PRE-YIELD DEFORMATION IN SOLUTION ANNEALED AND COLD-ROLLED AISI-TYPE-316 AUSTENITIC STAINLESS-STEEL

Heterogeneous dislocation substructure consisting of hard and soft reg ions has been introduced in nuclear grade AISI type 316 stainless stee l By cold rolling to different levels. The acoustic emission (AE) duri ng pre-yield tensile deformation is found to increase with the increas e in the extent of prior cold work. The pre-yield AE in solution annea led specimens is attributed to operation of Frank-Read and grain bound ary dislocation sources. The pre-yield AE behaviour in prior cold work ed specimens has been explained based on the composite deformation mod el, specifically attributing to the generation of coherent AE signal f rom the extensive glide of dislocations during plastic microyielding o f the soft regions in the substructure.