Influence of pre-deformation on the precipitation of Cu-rich clusters in RPV model steel

Abstract

The effect of pre-deformation on the precipitation process of Cu-rich clusters in reactor pressure vessels (RPV) model steel is studied. In this research, Fe-1.16wt%Cu binary alloy is selected as RPV model steel to simulate the precipitation process of Cu-rich clusters. The solid-solution Fe-Cu alloys were cold rolled with pre-deformation of 0, 10%, 25%, 40%, 60%, followed by aging at 450 °C for a series time. The dislocation density, Vickers hardness and microstructure evolution of Fe-Cu alloys after aging were determined. It is revealed that the Vickers hardness of un-deformed specimens reaches to peak hardness after aging at 450 °C for 100 h, while the specimens with larger dislocation density reach to peak hardness faster from the Vickers hardness test result. The result of transmission electron microscopy (TEM) indicates that pre-deformation promotes the process of precipitation of Cu-rich clusters and inhibits the growth of the Cu-rich clusters.