On the microstructure evolution of a nuclear-use steel after heavy ion irradiation

Ligang Song,Fan Ye,Shui Qiu,Xiao Liu,Ruiqian Zhang,Xianfeng Ma,Jianghua Li

doi:10.1088/1755-1315/639/1/012013

Abstract

A nuclear-use ferritic-martensitic steel was irradiated by 196 MeV Kr ions. Both the low damage level area and the high damage level area were investigated by a transmission electron microscope (TEM), to reveal the irradiated microstructural features. In low damage level area ranging from surface to 6 μm depth, there were a few dislocation loops and black dots induced by Kr irradiation. The type of dislocation loops could be primarily ao<100> or ao/2<100> type. In addition, it was found that the sink effect of grain boundaries and stability of small precipitates were evident.

Highlights

Ferritic-martensitic (F/M) steels have a number of attractive properties for use as cladding and ducts in reactors, including high strength at elevated temperatures, good compatibility and excellent swelling resistance under irradiation [1,2,3]
The transmission electron microscope (TEM) samples were fabricated by focused ion beam (FIB) lift-out technique with a FEI Quanta 3D FEG dual beam scanning electron microscopy (SEM)
Within depth of 6 μm, the damage level is lower than 3 dpa, but it was possible to induce dislocation loops by irradiation [6]

Summary

Introduction

Ferritic-martensitic (F/M) steels have a number of attractive properties for use as cladding and ducts in reactors, including high strength at elevated temperatures, good compatibility and excellent swelling resistance under irradiation [1,2,3]. The majority of the recent efforts had been focusing on the microstructure evolution during irradiation in reactors operating condition [4, 5]. The ions implantation provides an effective way to induce irradiation damage to simulate the neutron irradiation [6]. Phase stability of precipitates in ferritic-martensitic steel T91 under proton irradiation was investigated [7, 8]. There are many other studies on variable microstructure by utilizing ions implantation [11] at different irradiation condition such as temperature, dual beam ions irradiation. To provide additional insight into the microstructure evolution of FM steels [12] at high temperature, experiments were conducted using 196 MeV Kr ions at 550 oC

Methods

Results

Conclusion