Abstract: Impact and fracture toughness properties of the reactor coolant piping（RCP） 90°elbow made by static cast austenitic-ferritic（duplex） stainless steels for Qinshan phase II extension project are evaluated, after long time ageing and 10 years’ service at 325℃, according to the methods and procedures from IAEA and other international literatures. The evaluation results indicate that: the impact and fracture toughness properties of the elbow decrease obviously after 10years’ service at 325℃, but the impact properties remain in the safe range; after long time ageing, the impact value can not satisfy the design requirement anymore.