Determining the shear fracture properties of HIP joints of reduced-activation ferritic/martensitic steel by a torsion test

Nozawa, Takashi; Noh, S.; Tanigawa, Hiroyasu

A hot isostatic press (HIP) process is a key technology to fabricate a first wall with cooling channels of the fusion blanket system utilizing a reduced-activation ferritic/martensitic steel. This study aims to develop the torsion test method with a special emphasis to provide a reasonable and comprehensive method to determine interfacial shear properties of HIP joints during the torsional fracture process. Torsion test results identified that the torsion process shows yield of the base metal and following non-elastic deformation due to work hardening of the base metal. By considering this work hardening issue, we could propose a reasonable and realistic solution to determine the torsional yield shear stress and the ultimate torsional shear strength of the HIPped interface. Finally, representative torsion fracture process was identified.