A mechanism study on influence of strong external magnetic field on fracture properties of a ferromagnetic steel

Zheng Xie,Cuixiang Pei,Zhenmao Chen,Panpan Xu,Qun Li,Manru He,Shejuan Xie

doi:10.1063/1.5088876

Abstract

For some ferromagnetic metallic materials, measurable influence of strong external magnetic field on their fracture properties has been observed experimentally, i.e., an external magnetic field of large intensity can promote the propagation of the crack. In order to clarify the mechanism of this phenomenon, a fracture model is put forward in this paper based on reversal magnetic domain theory and minimum free energy algorithm and verified through observations of magnetic domains structure. Compact tensile (CT) specimens which were stretched in strong magnetic field are adopted to observe their magnetic domains structure with the powder grain method in practice. It is found that the crack in the CT specimen propagated mainly along the magnetic domain wall rather than passing through the domain body. Together with the experimental results, the fracture model for the rupture and propagation mechanism under strong magnetic field was discussed.

Highlights

A mechanism study on influence of strong external magnetic field on fracture properties of a ferromagnetic steel
To clarify the influence of strong external magnetic field, which is indispensable in a magnetic confined nuclear fusion reactor, on the fracture properties of key structural materials adopted in the fusion reactors, experimental researches have been conducted in several research groups
A new hypothesis is proposed based on the minimum free energy theory and its feasibility is studied through experimental observations of the magnetic domain structures of specimen ruptured in environment of large magnetic field

Summary

Introduction

A mechanism study on influence of strong external magnetic field on fracture properties of a ferromagnetic steel. According to the fracture experimental results in Ref. 5, the critical fracture force of the CLAM steel reduced significantly once a strong external magnetic field was applied.

Results

Conclusion