METHOD FOR PRODUCING ANISOTROPIC ELECTROTECHNICAL STEEL HAVING HIGH MAGNETIC PROPERTIES

摘要

The invention relates to the field of ferrous metallurgy. In order to produce cold-rolled anisotropic electrotechnical steel with low losses (?1,7,50= 1.0 W/kg) and high induction (?800 = 1.90 tesla), steel having a content of % 2.5 -3.5% by mass of silicon, 0.004 - 0.013% by mass of nitrogen, and 0.010 - 0.040% by mass of acid-soluble aluminium is melted, the product is poured into slabs, followed by hot rolling, annealing of the skelp, cold rolling, continuous decarbonizing annealing of the cold-rolled skelp, and nitriding and high-temperature annealing. Slabs having a thickness of 200-270 mm are placed into a heating furnace with a surface temperature of at least 450°C, are heated up to 1100-1200°C and rolled. The hot-rolled skelp is heated to 1070 - 1200°C, then cooled to 900 - 980°C, allowed to settle and rapidly cooled from 800-950°C at a rate of 20 - 50°C/sec with water of a temperature of 35 - 65°C. The continuous annealing of the cold-rolled skelp is carried out at a heating rate of 15 - 60°C/sec to 750-800°C, and decarbonization and nitriding are carried out at a temperature of 750 - 850°C in a nitrogen and hydrogen atmosphere containing ammonium N?3.