METHOD FOR PRODUCING HOT ROLLED SHEET PRODUCT Russian patent published in 2002 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method involves melting metal containing C, Mn, S in steel melting unit; discharging molten metal into ladle; performing after-charging of manganiferous materials and aluminum into ladle; feeding lime in an amount determined from expression: Q(l)= 0.122Al+107.05[C] +39.78[Mn] +236.45[Δ S] -0.13952T+221.35, where Q(l) is amount of lime, t; Al is amount of aluminum fed into ladle, t; C, Mn are content of carbon and manganese in metal before discharge, %; Δ S is difference of sulfur content before discharge of molten metal and in ready metal, %; T metal temperature before discharge of molten metal, C; blowing metal with inert gas; pouring into ingots and rolling, with rolling temperature at rolling final stage being within the range of 870-900 C; winding produced sheet blank into rolls at temperature, whose minimal and maximal values are determined from following expressions: T(w min)=166.3[Mn]-489.2[Al]+655.6[C] +507.5; T(w max)=199.1[Mn]+138.7[Al]+118.2[C]+529, where T(w min) is minimal winding temperature, C; T(w max) is maximal winding temperature, C; Al, C, Mn is content of aluminum, carbon and manganese in ready metal, %. Method is used for manufacture of rolled sheets from low-carbon rimming steel. EFFECT: increased efficiency by providing optimal oxygen content after metal reduction and optimal metal temperature before pouring, reduced surface defects and nonmetallic inclusions. 2 cl