Behaviour of P, Si, Ni impurities and Cr in self ion irradiated Fe-Cr alloys - Comparison to neutron irradiation

This paper presents an atom probe tomography study of phase transformation and solute segregation in Fe-Cr alloys of low purity under self-ion irradiation. Fe-9%Cr and Fe-12%Cr were irradiated at 100 degrees C, 300 degrees C and 420 degrees C at a dose of 0.5 dpa. Homogeneously distributed clusters enriched in Cr, P, Si and Ni are shown to format 300 degrees C and 420 degrees C but not at 100 degrees C. Study of the evolution of the segregation intensities of Cr, Si and P in the clusters with temperature under ion irradiation indicates that they form by a radiation induced mechanism. No alpha' clusters were observed whatever the irradiation temperature whereas they were observed in the same alloys after neutron irradiation at 300 degrees C at 0.6 dpa. Comparison of the solute cluster composition after ion irradiation and neutron irradiation, suggests that P atoms could play an important role in the appearance of the solute clusters by stabilizing point defect clusters that could later be enriched in Ni, Si and Cr. (C) 2014 Elsevier B.V. All rights reserved.