COLD ROLLING METHOD Russian patent published in 2008 - IPC B21B1/36 

FIELD: processes enhancing consumer's properties of steel sheets.

SUBSTANCE: method is designed for producing enhanced-quality thin-sheet low carbon steel with carbon content 0.18 - 0.22 mass%, thickness 0.60 - 1.35 mm,σ_B = 250 - 380 MPa. Method comprises steps of successively reducing blank of predetermined width at preset values of total ε_Σ and local ε according to passes reductions and at varying said values depending upon final thickness h of strips. Possibility for lowering sheet thickness is provided due to rolling strips of minimum thickness hmin = 0.60 - 0.77 for two passes from blank of any width from Bmin till Bmax; rolling strips with thickness hcp = 1.3 -1.72 hmin also for two passes of blank with width from Bmin till Bcp = 1.1 Bmin and for three passes from blank with width Bmax = 1.2Bmin; rolling strips with thickness hmax = 1,73 hmin and more for three passes of blank with width Bmin - Bcp; setting value ε_Σ in range 65 -70%. At rolling by two passes reduction value during first pass in first stand ε1 = 0.46εΣ and in second stand ε2 = 0.18εΣ; during second pass ε1 = 0.24εΣ, ε2 = 0.12εΣ. At rolling by three passes in first pass ε1 = 0.41εΣ, ε2 = 0.12εΣ and in second pass ε1 = 0.22εΣ, ε2=0.1εΣ and in third pass ε1 =0.1εΣ, ε2 = 0.05εΣ.

EFFECT: enhanced consumer's properties of thin-sheet low carbon steel.

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