Title:
PROCESS FOR THE PRODUCTION OF GRAIN ORIENTED ELECTRICAL STEEL STRIPS
Document Type and Number:
WIPO Patent Application WO2002050314
Kind Code:
A3
Abstract:
Process for the production of oriented grain electrical steel strips, in which a silicon steel, comprising at least 30 ppm of S, is directly cast as strip 1,5-4,5 mm thick and cold rolled to a final thickness of between 1,0 and 0,15 mm; characterised by the following staged: Cooling and deformation of the solidified strip to obtain a second phases distribution in which 600cm<-1> < Iz <1500 cm<-1> and Iy = 1.9 Fv/r (cm<-1>), Fv being the volume fraction of second phases stable at temperatures of less than 800 DEG C, and r being the precipitates mean radius, in cm.; Hot rolling between solidification and coiling of the strip at a temperature of not less than 750 DEG C, with a reduction ratio of between 15 and 60%; Cold rolling with reduction ratio of 60-92%; Cold rolled strip annealing at 750-1100 DEG C, with increase of the nitrogen content of at least 30 ppm with respect to the initial composition at the strip core, in nitriding atmosphere.
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Inventors:
FORTUNATI STEFANO (IT)
CICALE STEFANO (IT)
ROCCHI CLAUDIA (IT)
ABBRUZZESE GIUSEPPE (IT)
CICALE STEFANO (IT)
ROCCHI CLAUDIA (IT)
ABBRUZZESE GIUSEPPE (IT)
Application Number:
PCT/EP2001/014879
Publication Date:
August 22, 2002
Filing Date:
December 17, 2001
Export Citation:
Assignee:
THYSSENKRUPP ACCIAI SPECIALI (IT)
FORTUNATI STEFANO (IT)
CICALE STEFANO (IT)
ROCCHI CLAUDIA (IT)
ABBRUZZESE GIUSEPPE (IT)
FORTUNATI STEFANO (IT)
CICALE STEFANO (IT)
ROCCHI CLAUDIA (IT)
ABBRUZZESE GIUSEPPE (IT)
International Classes:
C21D8/12; C22C38/00; C22C38/02; C22C38/60; H01F1/16; C21D8/04; (IPC1-7): C21D8/12; C22C38/02
Domestic Patent References:
| WO1998041659A1 | 1998-09-24 | |||
| WO1998041660A1 | 1998-09-24 |
Foreign References:
| EP0390160A1 | 1990-10-03 | |||
| EP0947597A2 | 1999-10-06 | |||
| EP0326912A2 | 1989-08-09 |
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