Characterization of torsion fracture behavior of F82H HIP joints with damage monitoring by acoustic emission

Abstract

The acoustic emission (AE) technique was first applied to characterize the hot isostatic pressing (HIP) joint interface of reduced activation ferritic/martensitic (RAFM) steel and its applicability for the quality assurance was assessed. The preliminary evaluation identified the characteristic AE signal related to the cracking event at the HIP joint interface: loud and instantaneous AE, which is considered as a consequence of macro cracking. However it is very hard to detect any AE signals related to initial deformation prior to the maximum torque, e.g., yielding and work hardening. In contrast, it is clarified that the cumulative AE energy is closely related to the absorbed energy by torsion. Since it is recognized that the absorbed energy by torsion was dependent on the absorbed energy by Charpy impact test, a good correlation was eventually identified among them and this will be helpful in establishment of the AE technique for the quality assurance of the HIP joint interface.