This chapter outlines the background and history of electrical steels and the motivation behind their development and implementation in modern engineering. Early transformer, generator and motor developers soon realised that cores constructed from solid iron resulted in prohibitive eddy current losses, and their subsequent designs mitigated this effect with cores consisting of bundles of insulated iron wires and, later, laminated sheets of steel. Therefore, the demand for the first `electrical steel' became apparent. The authors discuss the chemical and physical properties found to be essential in achieving the best magnetic properties in electrical steels. These requirements include thickness, chemical composition, grain size, crystal orientation and coatings.

Chapter Contents:

• 13.1 History and development of electrical steels
• 13.1.1 Laminations
• 13.1.2 Increased resistivity
• 13.1.3 Purification
• 13.1.4 Grain size
• 13.1.5 Crystal orientation
• 13.1.6 Coatings
• 13.2 Metallurgical requirements and control
• 13.2.1 Thickness
• 13.2.2 Chemical composition
• 13.2.3 Grain size
• 13.2.4 Crystal orientation
• 13.2.5 Coatings
• References

Inspec keywords: crystal orientation; grain size; iron alloys; silicon alloys; ferromagnetic materials; eddy current losses

Other keywords: coating; crystal orientation; SiFe; thickness; electrical steels; eddy current losses; chemical composition; grain size

Subjects: Magnetic domain effects, magnetization curves, and hysteresis; Ferromagnetism of Fe and its alloys; Microstructure; Crystal morphology and orientation