Two RPV steels with American denomination ASTM A508 and ASME A533B hav
e been investigated with regard to radiation hardening, shift in ducti
le-to-brittle transition temperature and recovery behavior after therm
al annealing treatments. Main emphasis has been given to a through exa
mination and classification of fracture zones of tested Charpy-V speci
mens in dependence of irradiation and test conditions. The results of
this investigation have been compared with the data found in Russian r
eactor pressure vessel steels.