High Temperature Fracture of Candidate Gen IV Reactor Materials

Abstract

The likely candidate alloys for the Gen IV nuclear reactors consist of ferritic and martensitic (F/M) high Cr steels (e.g., Grade 91) for construction of high-temperature pipes and nozzles; and austenitic stainless steels, Ni-base alloys, and even oxide dispersion strengthened (ODS) alloys for various in-core components. In this paper, a brief summary is presented of the effects of temperature, stress, loading mode, environment, irradiation, and microstructure on fracture mechanisms and fractographic features of relevant materials. Practical fracture problems with some of these alloys are also discussed.