The nanostructure of non-oriented electrical steel sheets

Nanostructures of two non-oriented electrical steels were investigated in order to elucidate the influence of nanostructure and its components on magnetic properties. The main difference between the two samples was related to the mean grain size and level of core loss. Surprisingly, the sample with coarser ferrite grains exhibited higher core loss. For this reason (HR)TEM imaging was carried out. Precipitation reactions were monitored using differential scanning calorimetry (DSC). Light microscopy, FE-SEM/EDX and EBSD analyses were also performed to analyse the microstructures and crystallographic textures. The results were compared and related to the magnetic properties. It was shown that besides the microstructural components, the nanostructure and nanoprecipitates also have a crucial impact on the magnetic properties.