METHOD FOR PRODUCING GRAIN-ORIENTED ANISOTROPIC ELECTROTECHNICAL STEEL SHEETS

摘要

The invention relates to a method for producing grain-oriented anisotropic electrotechnical steel sheet, containing 0.008 to 0.025 % aluminium, 2.8 to 3.5 % silicon, 0.1 to 0.7 % copper, 0.005 to 0.012 nitrogen, less than 0.06 % carbon, 0.1 to 0.3 % manganese and less than 0.02 % sulphur. The method comprises the following steps: melting the raw material and producing slabs; heating said slabs to 1230 to 1300 °C; hot rolling; two-stage cold rolling; tempering; preferably, applying a magnesium oxide-based coating; and high-temperature annealing. The temperature T for heating the slabs prior to hot rolling is adjusted in dependence on the Al-content of the steel according to the following ratio: T(°C) = 1230 + ((Al%) - 0.008) * 5300 + 20, Al % being the proportion in wt. % of aluminium in the melt.