Nanoindentation study on the mechanical properties evolution of Fe-ion-irradiated A508-3 steel

The irradiation hardening of Chinese A508-3 steel was studied using nanoindentation technology. To address the issue of non-uniform damage caused by single-energy ion irradiation, this study utilized Fe ion beams at three different energies (1.2, 2.4, and 3.3 MeV) to generate irradiated samples with a quasi-uniform damage plateau, enabling a more accurate determination of hardness values at specific doses and establishing a more reliable quantitative relationship between hardness and irradiation dose. The samples were irradiated at 290 °C, consistent with the actual service temperature. Significant hardening was observed after irradiation, and the degree of hardening increased progressively with the irradiation dose. The relationship between the nano-hardness increment (∆H 0 ) and the irradiation dose was proposed, and the correlation between the yield strength increment (∆σ 1 ) and the damage level was established.