Irradiation Effects on Magnetic Properties in Neutron and Proton Irradiated Reactor Pressure Vessel Steel

Abstract

The effects of neutron and proton dose on the magnetic properties of a reactor pressure vessel (RPV) steel were investigated. The coercivity and maximum induction increased in two stages with respect to neutron dose, being nearly constant up to a dose of 1.5 x 10(-7) dpa, followed by a vapid increase up to a dose of 1.5 x 10(-5) dpa. The coercivity and maximum induction in the proton irradiated specimens also showed a two stage variation with respect to proton dose, namely a rapid increase up to a dose of 0.2 x 10(-2) dpa, then a decrease up to 1.2 x 10(-5) dpa. The Barkhausen noise (BN) amplitude in neutron irradiated specimens also varied in two stages in a reverse manner, the transition at the same dose of 1.5 x 10(-7) dpa. The BN amplitude in proton irradiated specimens decreased by 60 % up to 0.2 x 10(-2) dpa followed by an increase up to 1.2 x 10(-2) dpa, The results were in good accord with the one dimensional domain wall model considering file density of defects and wall energy.