Patent ID: 6045627
Filing Date: 2000-04-04
Classification: C21D,C22C,C23C,H01F

Abstract:
A method for producing a silicon steel sheet comprising the steps of:preparing a steel sheet containing Si in an amount of less than 4 wt. %;siliconizing the steel sheet in a non-oxidizing gas atmosphere containing SiCl.sub.4 to produce a steel sheet containing Si in an amount of from 4 to 10 wt. %;heat treating the siliconized steel sheet in a non-oxidizing gas atmosphere containing no SiCl.sub.4 to diffuse Si into an internal portion of the steel sheet;cooling the heat treated steel sheet at a cooling speed of 5.degree. C./sec. or more in a temperature range of from 300 to 700.degree. C., thereby to produce a silicon steel sheet having grain boundaries and carbides which are precipitated on the grain boundaries and have an area of 20% or less of an area of the grain boundaries.