Magnetic evaluation of hardening of thermal aged Cu-rich RPV steel

Copper-rich Reactor Pressure Vessel (RPV) steel was thermal aged at 440 °C up to 1450 h to study the influence of Cu-rich cluster on mechanical properties and magnetic properties of RPV. It is found that the tensile properties remain unchanged during thermal aging, while the hardness and coercivity both reach a weak peak at 120 h, and the variation of hardness and coercivity is linear. Moreover, the remanence and saturation magnetic induction reach a clear minimum at 120 h. Compared with Fe-Cu alloys, the change of mechanical properties and magnetic properties are much less in RPV steels due to aging precipitation.