The book chapter focuses on localised or microscopic properties of grain oriented (GO) and non-oriented (NO) steels. This ranges from the magnetic domain level to single crystal and grain-to-grain interactions. This is intended to show how the microstructure and controlling intrinsic magnetic properties influence the practical magnetic performance of commercial silicon-iron alloys.

Chapter Contents:

• 1.1 Overview of content of Chapter 1
• 1.2 Effects of grain structure on domains, losses and magnetostriction in GO steel
• 1.2.1 Static domain structures
• 1.2.2 Presence and effect of lancet domains
• 1.2.3 Effect of grain misorientation on surface domain structures
• 1.2.4 Effect of grain misorientation on losses and magnetostriction
• 1.3 Estimation of losses in single crystals of SiFe
• 1.3.1 Hysteresis loss caused by motion of a single domain wall
• 1.3.2 Total loss associated with a single domain wall in GO steel
• 1.4 Significance of the width of main domains in GO steels
• 1.5 Domain wall bowing in GO steel
• 1.6 Combined effect of main and supplementary domains in GO steel
• 1.6.1 Local effects of thickness on losses
• 1.6.2 Effect of grain size on losses
• 1.7 Wall spacing and losses in grains of GO SiFe under a.c. magnetisation
• 1.7.1 Effects related to main wall spacing
• 1.7.2 Grain-to-grain interactions across grain boundaries in GO steels
• 1.7.3 Domain refinement processes
• 1.7.3.1 The motivation for domain refinement
• 1.7.3.2 Domain refinement mechanisms
• 1.7.3.3 Theoretical models
• 1.8 Domain studies in NO electrical steels
• 1.9 Internal domain structure in GO steel
• 1.10 Rotational losses in single grains
• 1.11 Localised magnetostriction
• 1.11.1 Magnetostriction in single grains of GO steel
• 1.11.2 A hypothetical model of the effect of surrounding grains on the magnetostriction of a single grain
• 1.11.3 Localised stress sensitivity of magnetostriction of GO steel
• 1.12 Surface magnetic features of GO steel
• 1.12.1 Background
• 1.12.2 Variation of the tangential component of surface field
• 1.12.3 Localised flux density and loss distribution
• 1.13 Losses under PWM excitation
• 1.14 Defects and precipitates
• 1.15 Analysis of the stress due to the coating on GO steel
• 1.15.1 Coating-induced stress
• 1.15.2 Differential contraction mechanism
• 1.15.3 Total stress induced during the coating processes
• 1.15.4 Practical separation of effects of coating stresses
• 1.16 Barkhausen effect
• References

Inspec keywords: ferromagnetic materials; silicon alloys; iron alloys; magnetic domains; crystal microstructure

Other keywords: single crystal interactions; microstructure; grain oriented steels; commercial silicon-iron alloys; intrinsic magnetic properties; FeSi; localised microscopic properties; nonoriented steels; grain-to-grain interactions; magnetic domain level; magnetic performance

Subjects: Ferromagnetic materials; Microstructure; Ferromagnetism of Fe and its alloys; Magnetic domain walls and domain structure; Metals and alloys (engineering materials science)