METHOD OF MANUFACTURING HIGHLY GRAIN-ORIENTED EDGE COLD-ROLLED FERROSILICON TRANSFORMER STEEL Russian patent published in 1998 - IPC

FIELD: metallurgy, in particular, manufacture of electric sheet cold-rolled transformer steel. SUBSTANCE: edge grain orientation is attained in rolling of strip in cambered rolls with circular grooves on their working surfaces. Strip tension is maintained within 30-50% of strip material elasticity limit with production of longitudinal projections on the surface of one strip side. Projections are rolled-in by smooth rolls with strip tension up to 50-80%. Main part of strip matrix due to rolled-in projections is given tensile stress, and sections with rolled-in projections are given compression stress. In carrying out high-temperature annealing, tensile stresses present in strip ensure orientation of grain structure in direction of rolling and in rolling plane with concurrent equiaxial plastic tension of strip that improves strip flatness. A certain part of tensile stresses remains in strip that promotes reduction of magnetostriction effect on hysteresis. Present tangential stresses in strip between tensile and compression stresses allow control of strip grain structure which are realized at high-temperature recrystallization annealing. EFFECT: higher efficiency.