摘要 |
<p>The present invention relates to the production of a grain oriented electrical steel composition having a volume resistivity of at least 50 micro-ohm-cm. The melt composition of the steel consists essentially of, in weight %, about 0.08% max carbon, about 0.015 to about 0.05% aluminum, greater than about 2.25 to 7% silicon, greater than about 0.5% manganeseeq, about 0.001 to about 0.011% nitrogen, about 0.01% max sulfur, about 3% max chromium, about 1% max copper, about 2% max nickel and balance essentially iron. High levels of silicon are balanced with a manganese equivalent relationship which permits lower levels of carbon while still providing the desired levels of austenite during rolling and annealing. The processing also includes the addition of excess nitrogen to the steel prior to secondary grain growth which is subsequently removed during a purification treatment.</p> |