[2E09-12] Cladding Materials

[2E10] Evaluation of irradiation induced hardness and microstructure of Zry-2 under applied stress (1)

*Luwei Xue¹, Katsuhito Takahashi¹, Hideo Watanabe¹ (1. KYUSHU UNIVERSITY)

Keywords:Zirconium alloy, Applied stress, Ion irradiation, Radiation hardening, Dislocation loop

Zircaloy-2 is located closest to the fuel in boiled water reactors as the flue cladding tube, which has caused severe problems including dimensional changes, delayed hydride cracking, irradiation embrittlement in mechanical and physical properties that compromise their service life. During the operation, a large number of -type dislocation loops are formed in the early stage of irradiation which leads to the hardening of the material. As the irradiation dose increases, -type dislocation loops form while the material becomes severely embrittlement and cracked. In this presentation, to investigate the hardening at lower does, Zircaloy-2 was irradiated with Ni³⁺ ion with different doses under applied stress, followed by nanoindentation test for surface hardness and statistical analysis of microstructure to derive the contribution of -type dislocation loops to the hardening of the Zircaloy-2 below 3 dpa.