Specimen size effects on tensile properties of cold worked RAFM steel

• Cold-working can significantly change the tensile properties of RAFM steel and increase the number of specimen states; according to this work, the data tested by neutron irradiated SS-J specimen can basically reflect the macroscopic tensile properties of RAFM steel. • The variation trend of the mechanical properties of the specimens at the different cold work levels was generally consistent. The tensile properties of the corresponding materials can be evaluated based on the SS-J specimen. • By comparing with that of standard-sized specimens, the SS-J sized specimen studied in this paper does not significantly show size effect on the experimental results of the mechanical properties of the material. Changes in the mechanical properties of materials after neutron irradiation are key parameters for evaluating the properties of fusion reactor materials. Based on space, testing time span, and cost, small sized specimens are required for neutron irradiation and post-test of fusion reactor materials. In this work, the tensile properties of the small- and standard-sized specimens of 9Cr RAFM steel at different cold-work levels were tested from room temperature to 550 °C. The effects of cold-work deformation and specimen size on the tensile properties of materials were systematically analyzed, and the test data on the tensile properties of SS-J and standard-sized specimens were obtained. The effects of specimen size and cold-work deformation on the tensile properties of RAFM steel were analyzed. These research results can provide an important reference for the analysis of test data after neutron irradiation.