Abstract: Embrittlement of a 2.25Cr1Mo steel stemming from neutron irradiation at 270oC is studied by virtue of small punch testing in conjunction with scanning electron microscopy. The ductile-brittle transition temperature determined by the small punch test is much lower than that determined by the standard Charpy test. There is some irradiation-induced embrittlement effect after the steel is irradiated for 46 days with a neutron dose rate of 1.05?0-8 dpa/s.

Key words: Irradiation, Embrittlement, Segregation, Low alloy steels, Pressure vessels,