PRODUCTION OF HIGH SILICON STEEL SHEET EXCELLENT IN MAGNETIC PROPERTY AND MECHANICAL PROPERTY BY PACK CEMENTATION METHOD

摘要

PURPOSE: To produce a high silicon steel sheet excellent in magnetic properties and mechanical properties by subjecting a material steel sheet containing specific amounts of Si to siliconizing treatment in a gaseous mixture of Si compound and nitrogen, subjecting Si to thermal diffusion in a sheet thickness direction, and performing heat treatment in a specific atmosphere. ;CONSTITUTION: A material steel sheet having a composition containing, by weight, 4% Si, preferably ≤0.0050% Al, and 0.0050% N is subjected to siliconizing treatment in a gaseous mixture of Si compound and nitrogen. Subsequently, diffusion heat treatment is done to diffuse Si in a sheet thickness direction, and then, heat treatment is performed in vacuum of partial pressure of nitrogen P(N₂) satisfying inequality logP(N₂)--0.93×10⁸/T^2-58 [where P(N₂) means partial pressure of nitrogen(atm) and T means heat treatment temp. (°C)] or in a reducing or nonoxidizing atmosphere satisfying the inequality. By this method, the high silicon steel sheet excellent in magnetic properties and mechanical properties can be obtained.;COPYRIGHT: (C)1993,JPO&Japio