METHOD OF MAKING COLD ROLLED STRIP OR SHEET AND STEEL SHEET Russian patent published in 1994 - IPC

FIELD: production of belts or sheets. SUBSTANCE: method comprises steps of casting slabs with thickness 210 mm from melt, containing (mass %): 0.44 C, Si - 0.025, Mn - 0.25, P - 0.013, S - 0.05, Al - 0.054, N - 0.032, V - 0.02; heating it up to 1250 C and rolling out till a thickness value, equal to 3 mm, coiling and cooling up to 20 C; after etching the belt performing cold rolling of the sheet with reduction value 10-89% till the thickness value of a thin sheet and coiling; annealing at 700 C, skin rolling and coiling at 520-1100 C. The steel sheet has a recrystallization structure with ferrite grain size less than A TM 7 upon titanium content 0.01% and less than A TM 9 upon titanium content from 0.015 up to 0.004%. EFFECT: enhanced quality of steel sheet. 5 cl, 3 tbl