Magnetic characterisation of grain size and precipitate distribution by major and minor BH loop measurements

Tensorial permeability microstructure model considering crystallographic texture and grain size for evaluation of magnetic anisotropy in polycrystalline steels

“…( 9). This behaviour also agrees well with the literature reporting the magnetic permeability values increase with the ferrite grain size by a similar inverse or inverse square root relationship in extra-low carbon steels [31,34] or in non-orientated electrical steels [35]. The results prove that the present model has captured the grain size effects by considering the loss of elementary domains to the grain boundaries through introducing the parameter c g .…”

Consideration of Magnetic Measurements for Characterisation of Ferrite–Martensite Commercial Dual-Phase (DP) Steel and Basis for Optimisation of the Operating Magnetic Field for Open Loop Deployable Sensors

“…It should be emphasized that when there is more than one microstructural parameter affecting the mechanical and magnetic performance, their influence on magnetic permeability cannot be separated. It should be noted that besides the effect of ferrite grain size and phase fraction, other parameters such as inclusions, chemical composition differences [20] and precipitates [6] are less significant (in DP steels) on properties and can be considered as second-order influences after ferrite grain size and phase fraction for DP steel samples, and they will be similar for the steels considered in this work as the commercial DP steels have been processed under similar conditions.…”

“…In recent years, the use of magnetic methods for nondestructive evaluation/ characterisation of steels has increased rapidly [4][5][6][7][8]. For ferromagnetic materials, the interaction between lattice imperfections and Bloch walls is reasonably well explained [9], and characteristic magnetic flux density (B)-magnetic field strength (H) curves are detected.…”

“…There have been many investigations on the empirical relationships between minor/major loop measurements and the assessment of mechanical properties such as hardness and tensile strength (UTS) [10][11][12] or minor/major loop to assess grain size and precipitates [6] as an inspection method for the cold rolling process [16,17] and creep detection [18]; however, few studies are available on detailed correlations between the measured magnetic permeability at different applied magnetic fields and the sensitivity to different microstructural features.…”

Dynamic Coercivity of Tempered Ferritic Steel Subjected to Creep-Fatigue for Nondestructive Evaluation by Reversible Permeability

“…Sgobba [11] reported that the saturation magnetization is not strongly influenced by purity, while coercivity and permeability strongly depend on the purity and crystallographic features in iron. In addition, Liu et al [12] studied the precipitates in extra-low-carbon steel by characteristic magnetic parameters measured from major and minor magnetization loops. Most of all, the dependence of coercivity on grain size is well-known to be an inverse square root relationship.…”