Steel sheet with a high Si content (>3.5%Si) is difficult to process. These high Si steels are interesting in electrical applications because of the effect of Si on the magnetostriction and the electrical resistivity. Alternative methods have therefore been proposed to obtain high Si-contents, e.g. PVD of Si on sheet steel, followed by diffusion annealing. As an alternative process, 3% Si steel substrates were immersed in hyper-eutectic Al-Si-alloys using conventional sheet steel hot dipping technology with an appropriate surface treatment. Diffusion annealing experiments were carried out to obtain a sufficient amount of Si in solution in the steel. The tests were carried out with a hypereutectic bath composition, in order to obtain pure Si as primarily solidified phase. The best processing conditions in these experiments were found to be as follows: Al-25.6%Si melt composition, 850 degreesC melt temperature and 5 sec dipping time where primary Si crystals were nucleated within a matrix of Al-Si eutectic. The contribution focuses on the microstructural changes in the coating and near-surface region of the steel after the hot-dipping.