Fe-6.Swt% Si alloy is an excellent soft magnetic material, but becomes extremely brittle.Thus, it is very difficult to produce thin sheet by conventional rolling.To avoid rolling problems, a process of electrodepositing silicon on 3wt% Si sheet in KCl-NaCl-NaF-SiO2 molten salts followed by diffusion annealing was developed and is an alternative production route to obtain steel with 6.5wt% Si.The proper proportion of molten salts is the key to the successful preparation of Fe-6.5wt% Si steel.