PROCESS OF HEATING OF SLABS OF ELECTRICAL SHEET ANISOTROPIC STEEL FOR HOT ROLLING Russian patent published in 2000 - IPC

FIELD: metallurgy, production of electrical sheet steel, heating of slabs of transformer steel cast continuously. SUBSTANCE: technical result of usage of invention lies in provision of condition for solution of inclusions of nitride phase-inhibitor FIN in process of heating of slabs of electrical sheet anisotropic steel in furnaces with stepping girders. This is necessary precondition for formation of finely dispersed inclusions of nitride phase-inhibitor AIN in hot-rolled strips. Mentioned technical result is achieved as heating of slabs is conducted continuously along entire length of furnace in process of transportation of slabs by stepping girders, after filling of second weld and soaking zones of furnace by slabs of electrical sheet anisotropic steel movement of slabs is stopped, temperature along length of second weld and soaking zones of furnace is equalized by reduction of temperature at top of second weld zone by 30-50 C and by rise of temperature at top of soaking zone by 20-30 C. Then temperature on bottom of both zones is increased and isothermal soaking of slabs which duration is set by dependence τ_в = 112,65•10^-4•H2c

/Si+31822,32/τ_н-247,11 is carried out, where τ_в is time of isothermal soaking, min; 112.65 is dimensional coefficient, min %/sq. mm; H_c is thickness of slabs, mm; Si is silicon fraction of total mass of steel, %; 31822.32 is dimensional coefficient, min²; τ_н is time of continuous heating of slabs in process of their transportation in continuous furnace with stepping girders with filling of second weld and soaking zones of furnace, min; 247.11 is dimensional coefficient , min. EFFECT: provision for solution of inclusions of nitride phase-inhibitor FIN in process of heating of slabs. 1 cl, 2 dwg, 2 tbl