Research On High Temperature Mechanical Property And Irradiation Performance Of C276Alloy As Candidate Material For The Fuel Cladding In Supercritical Water Reactor (SCWR)

High temperature mechanical property and anti-irradiation performance of C276alloy as a candidate material for the fuel cladding in supercritical water reactor is researched, in pursuance from "973" project as "basic research on key scientific problem of supercritical water reactor". First, high temperature mechanical property of C276alloy is evaluated, and scanning electron microscope and X-ray diffraction are used to investigate strengthening mechanisms and creep-fatigue damage mechanisms of C276alloy. Then, heavy ions irradiation and H, He and Si ions irradiation is performed. Nano-indentation instrument, transmission electron microscopy and Raman spectroscope are used to investigate anti-irradiation performance of C276alloy. It turns out as follow.Good high-temperature tensile strength of C276at500℃～650℃arises from co-effects of main solid solution-strengthen and possible deformation twin-strengthen. A good high temperature persistent resistance of the C276alloy at650℃maybe arise from co-effects of solid solution-strengthen, and precipitation-strengthen.The fatigue life changes due to the introduction of holding period were dependent on the imposed total strain range. At total strain range with0.35%～0.4%, the fatigue life reduction by imposing holding period is obvious by the action of the enhanced fatigue crack-growth-rate and the presence of some micro cracks and cavities. At total strain range with0.45%～0.5%, the fatigue life increased by imposing holding period due to the closed micro cracks and cavities.Irradiation hardening and radiation-induced segregation of C276alloy is found by H, He and Si ions irradiation. By Xe heavy ion irradiation, the changes of nanohardness are dependent on the temperature and damage dose, and obvious void swelling is found.In conclusion, good high-temperature strength of C276arises from co-effects of main solid solution-strengthen, possible deformation twin-strengthen and precipitation-strengthen. But C276alloy is susceptible to proton and heavy ion irradiation. Further research on C276alloy is needed to decide whether to apply C276to the fuel cladding in supercritical water reactor.