METHOD FOR SLITTING SLABS AT ROLLING Russian patent published in 2002 - IPC

FIELD: rolled stock production, namely manufacture of rectangular cross section bar and sheet blanks from slabs by multistrand rolling process. SUBSTANCE: method comprises steps of forming from slabs in several passes rectangular cross section blanks mutually joined by bridges at using rolls with multigrooved passes; then breaking bridges. Blanks are formed by means of slitting ridges having angles 25-35 degrees by two passes; in first pass forming bridges with thickness consisting (65-75)% of slab thickness; in second pass forming bridges with thickness consisting (8-12)% of slab thickness at simultaneously reducing blanks by thickness by (10-20)%. In variants of invention second pair of rolls realizes biting of blank at forced supporting it from backwards along slab width consisting 0.96-0.98 of total width of roll grooved pass along parting in order to provide self- centering in grooved pass of roll. Bridges may be broken in rolls with multigrooved finish passes arranged in staggered fashion. Difference of diameters along bottom of adjacent grooved passes is set according to relation /D1-D2/ = (1.5-2.5)δ, where D1, D2 - diameters along bottoms of adjacent grooved passes, δ - thickness of broken blank. EFFECT: possibility for making flawless blanks at minimum number of passes. 4 cl, 5 dwg, 1 tbl