Suchergebnisse

ABSTRACT: The Small Punch test has been recently used to estimate mechanical properties of steels in aggressive environments. This technique, very interesting when there is shortage of material, consists in using a small plane specimen and punch it until it fails. The type of tests normally used are under a constant load in an aggressive environment, with the target to determine the threshold stress. However, this is an inaccurate technique which takes time, as the tests are quite slow. In this paper, the Small Punch tests are combined with the step loading technique collected in the standard ASTM F1624 [1] to obtain the value of threshold stress of an S420 steel in a total time of approximately one week. The ASTM F1624 indicates how to apply constant load steps in hydrogen embrittlement environments, increasing them subsequently and adapting their duration until the specimen fails. The environment is created by means of cathodic polarization of cylindrical tensile specimens in an acid electrolyte. A batch of standard tests are performed to validate the methodology. ; The present work was performed in the University of Cantabria, through the post-doctoral contracts program (budgetary application 62.0000.64251), and supported by the Government of Cantabria and the University of Cantabria in the framework of "Proyectos Puente 2019" call.

ABSTRACT: This work provides an overview of the FRACTESUS project (Euratom work programme 2019-2020). The European Union has defined clear short and long-term objectives to achieve its energy transition towards sustainable energy and a climate neutral economy by 2050. The success of this transition relies on the combination of energy efficiency and low carbon energy in all sectors of the economy. In all electricity mix scenarios up to 2050, one needs to rely on a combination of existing nuclear power plants, long-term operation, new nuclear build and future nuclear systems. The safety and operability of nuclear systems heavily rely on strategies where the integrity of structural materials plays an essential role. Due to material availability and/or irradiation constraints, the use of small sized specimens to obtain reliable measurements of the fracture resistance is needed by the nuclear industry to comply with safety directives. Measurement of fracture toughness using small-sized specimens has already been shown to be possible in both unirradiated and irradiated conditions. However, significant work is still required to achieve European regulatory acceptance. The goal of FRACTESUS is to join efforts to establish the foundation of small specimen fracture toughness validation and demonstration to address the different national regulatory authority concerns. ; This project is receiving funding from the Euratom work programme 2019-2020. The contributions of all partners in the FRACTESUS project are also acknowledged