Magnetic investigations on irradiation-induced nanoscale precipitation in reactor pressure vessel steels: A first-order reversal curve study

We have investigated magnetic properties for reactor pressure vessel model alloys with variable Cu contents, subjected to neutron irradiation up a fluence of 9×1019 n cm−2. Unlike monotonic increase microhardness fluence, the major-loop coercivity decreases at higher and decrease becomes larger alloy containing amount Cu. The measurements first-order reversal curves (FORCs) high-Cu show that position FORC distribution peak shifts toward lower just after irradiation, followed by slight increase, associated broadening along both interaction field axes. results can be explained enhancement inhomogeneity in matrix due precipitation an increasing magnetostatic between local regions different coercivity. method using FORCs possible technique which provides in-depth information on microstructural changes is not obtained conventional major hysteresis loop.