Recent developments in non-oriented electrical steels

Abstract

This paper gives an overview of developments in the field of non-oriented electrical steels that are widely used in motor cores in recent years, focusing mainly on texture control. ND//<100> texture is recognized as the ideal texture for application to motor cores. To obtain a suitable texture, precise control is required during each manufacturing process. This involves adjusting the chemical components during the steel making, fine temperature and reduction control during hot rolling, temperature control during hot-band annealing, temperature and reduction control during cold rolling and heating rate and temperature control during final annealing. High silicon Fe-Si alloy containing 6.5 mass% Si has been recognized as a promising core material for high frequency applications. When producing high silicon steel by the continuous chemical vapor deposition (CVD) siliconizing process, materials with a gradient Si concentration in the sheet thickness direction have been found to display superior high-frequency iron loss.