Patent ID: 6582528
Filing Date: 2003-06-24
Classification: C21D,C22C

Abstract:
A method for manufacturing a non-grain oriented electric sheet comprising:introducing steel input stock as a heated and prerolled slab into a group of finishing roll stands at an entry temperature of &lE;1100Â° C., wherein a reheating temperature (TBR) with a maximal deviation of Â±20Â° C. corresponds to a reheating target temperature (TZBR) determined as follows: TZBR[Â° C.]=1195Â° C.+12.716*(GSi+2GAl) whereinTZBR: Target temperature of reheated slab GSi: Si content in weight-% GAl: Al content in weight-%, and wherein the steel input stock contains (in weight-%)C: &lE;0.06% Si: 0.03-2.5% Al: &lE;0.4% Mn: 0.05-1.0% S: &lE;0.02% balance iron and residual impurities; hot-rolling the slab into a hot strip with a thickness of <3.5 mm at a final rolling temperature (TET)&gE;770Â° C., wherein TET corresponds to a temperature of the steel input stock exiting the finishing roll stands; and coiling up the hot strip at a coiling temperature (THT) determined as follows with a maximal deviation of Â±10Â° C.: THT[Â° C.]=154âˆ’1.8&agr;t+0.577TET+111d/d0 whereind0: Reference thickness of the hot strip=3 mm d: Actual thickness of the hot strip in mm t: Time in seconds between the end of the hot rolling and coiling &agr;: 0.7 per second to 1.3 per second cooling factor, wherein the hot strip is subsequently pickled without being first annealed, and, after pickling, cold-rolled into a cold strip with a thickness of 0.2-1 mm at an overall maximal deformation level of 85%, and wherein the cold strip is subjected to a final treatment.