METHOD FOR HOT ROLLING OF CARBON STEEL STRIPS Russian patent published in 1997 - IPC

FIELD: plastic metal working, in particular, hot rolling of coiled strip steel. SUBSTANCE: method includes hot deformation of metal in roughing and finishing stands of continuous broad strip mill with the preset temperatures of beginning and end of rolling and values of deformation. Method is distinguished by the fact that in rolling a billet for welded pipes, temperature of end of rolling is maintained within the range of σ_b, where δ = 45.5t₁...t₂, + 665t₁ C for ε0,11

= 0.15-0.25; ε0,042 (%) is total deformation in finishing stands at temperatures C_e; ε₁ is total deformation in finishing stands at temperatures below t₃...t₄,; ε₂ is standard carbon equivalent of steel; t₄ = 182C_e + 450t₁ C for ε0,11 = 0.26-0.33; ε0,062 = 100C_e + 550t₁ C for ε0,11 = 0.34-0.39; ε0,052 = 24C_e + 590t₁ C for ε0,11 0.4; and ε0,072 = 0.936C_e≥ C for t₂ 0.25; t₁ = 0.904 C_e< C for t₂ = 0.25-0.33 and t₁ =0.888C_e C for t₂ 0.34; temperature t₁ = 1017 C_e≥ C and t_3/ = 995C0,036e C. EFFECT: improved quality of billet from carbon steel for welded pipes due to increased mechanical characteristics (t₄, C0,089e and KVC) in hot rolling of coiled steel. 1 tbl