Molten Salt Pulse Electrodeposition of Silicon on Low Silicon Steel

Abstract

Low silicon steel was siliconized by pulse electrodeposition from KCl–NaCl–NaF–SiO₂ molten salts and high silicon steel containing 6.5 mass% Si was prepared by followed diffusion annealing. The composition depth profile, the cross-section micrograph and the phase structure of the siliconized layer were characterized with glow discharge optical emission spectroscopy (GDOES), optical microscope (OM), scanning electron microscopy (SEM) with an X-ray energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The textures of substrate, deposited sample and high silicon steel were analyzed by the orientation distribution function (ODF). The results showed that Si was almost homogeneously distributed in the siliconized layer. The siliconized layer had a two-layer structure. The top layer composed of columnar grains and a layer with equiaxed grains close to the substrate. The phase structure of the layer was composed of Fe₃Si with (110) preferred orientation. After diffusion annealing the undesirable γ-fiber type texture {111}<110> and {111}<112> weakened, both easy magnetization direction Goss texture ({110}<001>) and cube texture {100}<001> were intensified.