Influence of electron irradiation on the microstructure of ferritic model alloys

Understanding the mechanisms at the origin of radiation embrittlement is of great interest for predicting the evolution of reactor vessel steel during nuclear power plant running. To examine the behaviour of different solutes under irradiation, electron irradiation has been performed with a Van de Graff accelerator on two model alloys (Fe–0.1%Cu and Fe–1.5%Mn–0.8%Ni–0.12%Cu–0.01%P) and a commercial steel. The nanostructure of these materials has been characterized by atom probe techniques before and after irradiation. The results show the influence of the copper content of the material on the formation of copper-rich clusters and also the behaviour of phosphorus under irradiation. Comparison between these results and results on ion irradiation determines the influence of the way in which point defects are created (isolated Frenkel pairs or displacement cascades) on the ability of copper atoms to gather. Copyright © 2004 John Wiley & Sons, Ltd.