公开(公告)号：US11239012B2

公开(公告)日：2022-02-01

申请号：US14638338

申请日：2015-03-04

Applicant: SMS Group GmbH

Inventor： Andreas Boettcher ,  Christian Klinkenberg ,  Ingo Schuster

IPC: C21D1/42 ,  H01F1/147 ,  C21D8/12 ,  C21D3/04 ,  C21D6/00 ,  C21D9/52 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C23C8/02 ,  C23C8/26 ,  H01F41/02

Abstract: A process for producing grain-oriented electrical steel strip by means of thin slab continuous casting and which includes continuously casting the smelt by thin slab continuous casting, subjecting the thin slabs to homogenization annealing at a maximum temperature of 1250° C. and heating to a temperature between 1350° C. and 1380° C., and continuously hot rolling the thin slabs to form a hot-rolled strip, with cooling and reeling the hot-rolled strip to form a coil and cold rolling the hot-rolled strip to a nominal thickness, with subjecting the cold-rolled strip to recrystallization, decarburization and nitridation annealing, which includes a decarburization annealing phase and a subsequent nitridation annealing phase, with an intermediate reduction annealing phase being interposed between the decarburization annealing phase and the nitridation annealing phase, whereby a cold-rolled strip is obtained, which primary recrystallized grains have a circle equivalent mean size (diameter) between 22 μm and 25 μm.

公开(公告)号：US20170283903A1

公开(公告)日：2017-10-05

申请号：US15631577

申请日：2017-06-23

Applicant: SMS Group GmbH

Inventor： Andreas Boettcher ,  Christian Klinkenberg ,  Ingo Schuster

IPC: C21D9/52 ,  C23C8/26 ,  C21D1/42 ,  C21D3/04 ,  C22C38/02 ,  C22C38/50 ,  C22C38/42 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C21D8/12 ,  C23F17/00

CPC classification number: C21D9/52 ,  C21D1/42 ,  C21D3/04 ,  C21D6/005 ,  C21D6/008 ,  C21D8/1205 ,  C21D8/1222 ,  C21D8/1233 ,  C21D8/1255 ,  C21D8/1261 ,  C21D8/1272 ,  C21D8/1283 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/16 ,  C22C38/42 ,  C22C38/50 ,  C23C8/02 ,  C23C8/26 ,  C23C8/80 ,  C23F17/00 ,  H01F1/14766 ,  H01F1/16 ,  Y02P10/253

Abstract: A process for producing grain-oriented electrical steel strip by means of thin slab continuous casting, comprising the following process steps: a) smelting a steel, b) continuously casting the smelt by thin slab continuous casting, c) heating up the thin slabs and subjecting the slabs to homogenization annealing at a maximum temperature of 1250° C., d) heating to a temperature between 1250° C. and 1350° C., e) continuously hot rolling the thin slabs to form a hot-rolled strip, f) cooling and reeling the hot-rolled strip to form a coil, g) annealing the hot-rolled strip after reeling and prior to a subsequent cold rolling step, h) cold rolling the hot-rolled strip to the nominal usable thickness, i) subjecting the cold-rolled strip to recrystallization, decarburization and nitridation annealing, j) applying an annealing separator (non-stick layer) to the strip surface of the cold-rolled strip, k) subjecting the cold-rolled strip to secondary recrystallization annealing, forming a finished steel strip having a pronounced Goss texture, and l) stress-free annealing the finished steel strip, which has been coated with an insulating layer, provides an improved process for producing grain-oriented electrical steel strip by means of thin slab continuous casting. This is achieved in that the recrystallization, decarburization and nitridation annealing of the cold-rolled strip in process step h) comprises a decarburization annealing phase and a subsequent nitridation annealing phase, with an intermediate reduction annealing phase being interposed between the decarburization annealing phase and the nitridation annealing phase, and carried out at a temperature ranging from 820° C.-890° C., for a maximum period of 40 seconds, with a dry, gaseous annealing atmosphere, which contains nitrogen (N2) and hydrogen (H2) and acts on the cold-rolled strip, and which has a water vapor/hydrogen partial pressure ratio pH2O/pH2 of less than 0.10.