چكيده به لاتين
Abstract:
Transformers play an important role in electrical industry. Silicon steel is used commonly in
the core of transformers. By time passing, amorphous ribbon and nanostructure sheets are
used to reduce the level of energy dissipation in the core made of soft magnetic material
layers. In order to have the layer insulated, it is essential to apply an insulating coating on the steel layers. In this study, soft magnetic silicon steel samples were first MgO-coated by
electrochemical process. Steel samples were coated for 1 hour by 0.1 M solution
Mg(NO3)2.6H2O and then dried in air and heat treated in furnace. Secondly, silicon steel
samples were immersed in the slurry of MgO ،Cr2O3 ،TiO2 and Fe2O3 and then dried. The
samples were then immersed in the slurry consisting of phosphoric acid, chromic acid,
colloid silica and distilled water and finally heated at 550°C.
In order to better understand the morphology and phase analysis, SEM and XRD were done which completed by polarization test to investigate the insulation and corrosion properties.
The results show that during the immersion process, the resistance increased from 162.9 to 214 KOh which proves better insulation and corrosion properties. On the other hand, coating on the amorphous ribbon increased the resistance of layers from 46.87 KOh to 32.57 MOh which leads to better insulation properties and decreasing the corrosion factors of ribbons.
Keywords: silicon steel, amorphous ribbon, immersion coating, electrochemical coating,
electrical insulation.
