Magnetic Properties of Thermally Aged Fe-Cu Alloys with Pre-deformation

Magnetic properties of thermally aged Fe-Cu alloys with pre-deformation have been evaluated to improve the understanding of using magnetic technology for the nondestructive evaluation (NDE) of irradiation embrittlement in reactor pressure vessel (RPV) steels. Fe-Cu alloys with and without pre-deformation were thermally aged at 500 °C and the changes in microstructure, mechanical properties and magnetic properties were determined. It is found that the strain-induced dislocations recover and the Cu-rich particles precipitate during the aging process, and the magnetic properties variation depends on the combined influence of these two factors. From the point of view of NDE, a fully tempered or annealed microstructure is favorable before RPV is put into service. These results improve the understanding of magnetic property evolution in actual RPV steels and help to develop NDE theory for irradiation embrittlement.