摘要 |
<p>The method of producing grain oriented silicon-iron sheet comprising the steps of:… (a) providing fine-grained, decarburized, and primary recrystallized silicon-iron intermediate product sheet material, said material containing from 2.2% to 4.5% silicon, boron, manganese up to 0.10%, said material having a manganese-to-sulfur ratio of at least 2.1 and not more than about 20 parts per million solute nitrogen;… (b) covering said sheet with an electrically insulating boron-containing adherent coating;… (c) heating said coated sheet in a first atmosphere comprising hydrogen and at least about 20 volume percent nitrogen to a first temper, e.g., of substantially 1050 DEG C, developing thereby a cube-on-edge secondary recrystallization texture in said sheet; and… (d) increasing the temperature of said sheet to a second temperature, e.g., of substantially 1175 DEG C, and holding said sheet at said second temperature in a second atmosphere consisting essentially of hydrogen for a predetermined time, e.g., of substantially three hours, effecting thereby substantial removal of carbon, sulfur and nitrogen.</p> |