초록 ▼

A method of producing a non-oriented electromagnetic steel strip by subjecting a low-carbon steel slab to hot-rolling, cold rolling at a small reduction and first annealing. In order to improve magnetic flux density and surface appearance of the product, specific conditions are employed so as to coa

A method of producing a non-oriented electromagnetic steel strip by subjecting a low-carbon steel slab to hot-rolling, cold rolling at a small reduction and first annealing. In order to improve magnetic flux density and surface appearance of the product, specific conditions are employed so as to coarsen the crystalline structure to obtain a controlled and moderate crystal grain size after the annealing. The slab is cold-rolled at a rolling reduction of about 5 to 15% and is subjected to first annealing by heating at a rate of about 3°C./sec or higher and holding the strip for about 5 to 30 seconds at 850°C. to the A3 transformation temperature of the steel, while controlling the crystal grain size to about 100 to 200 m

대표청구항 ▼

A method of producing a non-oriented electromagnetic steel strip having superior magnetic properties and appearance, comprising the steps of: preparing a slab from a steel which includes components consisting essentially of, by weight, up to about 0.02% of C, up to about 4.0% of Si plus Al or Si alo

A method of producing a non-oriented electromagnetic steel strip having superior magnetic properties and appearance, comprising the steps of: preparing a slab from a steel which includes components consisting essentially of, by weight, up to about 0.02% of C, up to about 4.0% of Si plus Al or Si alone, up to about 1.0% of Mn, up to about 0.2% of P and the balance substantially Fe; hot-rolling said slab to form a hot-rolled strip; subjecting said hot-rolled strip to a first cold rolling conducted at a rolling reduction controlled between about 5 and 15% to form a first cold-rolled strip; subjecting the first cold-rolled strip to a first annealing step; controlling the temperature and duration of said first annealing step to produce a crystal grain size ranging from about 100 to 200 m3°C./sec and 7°C./sec and a maximum temperature is maintained for about 5 to 30 seconds; subjecting the resulting annealed strip to cold rolling to reduce the annealed strip thickness; and subjecting the resulting cold-rolled strip to final annealing.