Electrical Steel

Types of electrical steel

Non-oriented fully processed electrical steel

Non-oriented, fully processed electrical steel has varying silicon levels that range from 0.5% to 3.25% Si. It has uniform magnetic properties in all directions. This type of electrical steel does not require recrystallisation processes to develop its properties. The low silicon alloy grades provide better magnetic permeability and thermal conductivity. For high alloy grades, better performance is expected in high frequencies, with very low losses. This type is excellent for magnetic circuits in motors, transformers, and electrical system housing. This fully processed type provides difficulty in punchability due to a completed annealing process. Organic coatings are added to improve lubrication in the punching process.

Non-oriented semi-processed electrical steel 

Non-oriented semi-processed electrical steels are largely non-silicon alloyed steel and are annealed at low temperatures after the final cold rolling. The end-user, however, has to provide the final stress-relief anneal according to the steel’s intended application. The punchability of this electrical steel type is better than the non-oriented fully processed type, so organic coatings are not required. Non-oriented semi-processed grades are good core materials for small rotors, stators, and small power transformers.

Grain-oriented electrical steel 

Grain-oriented electrical steels are composed of iron with 3% Si content with grains oriented to deliver high permeability and low energy loss. Grain-oriented grades have strong crystallographic properties. This type undergoes a recrystallisation process resulting in an enhanced grain structure that exhibits better magnetic properties in the rolling direction of the sheet. Grain-oriented steels are mostly used for non-rotating applications, such as transformers.