Tensile, Embrittlement and Creep Property Determination with Improved Small Punch Testing Equipment and Assessment Methods

With the miniature small punch (SP) testing techniques a range of important material properties can be evaluated. The main benefit of the SP testing is the small amount of material needed for testing. However, the SP test is multi-axial in nature and the deformation and the stress response in the thin specimen disc is complex. The interpretation of SP test results is challenging and simplified transformation equations to acquire representative values for comparison with uniaxial results are still debated. Under these circumstances, the repeatability and reproducibility of SP tests deserve particular attention in order to reduce methodological uncertainties to a minimum. In this paper SP test data is generated following the basic SP testing Code of Practice and improvements in the testing equipment, loading details and post-test examination routines are proposed. The main material used is the ferritic-martensitic grade 91 steel but also SP creep results from a much less ductile ODS tests are presented. The acquired results are compared to public domain results. Computed X-ray tomography giving 3D high-resolution measurements of specimen deformation specifics has been successfully used for post-test examination and rupture ductility evaluation.JRC.F.4-Innovative Technologies for Nuclear Reactor Safet