The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 17, 2005
Filed:
Dec. 17, 2001
Stefano Fortunati, Rome, IT;
Stefano Cicale', Rome, IT;
Claudia Rocchi, Rome, IT;
Giuseppe Abbruzzese, Rome, IT;
Stefano Fortunati, Rome, IT;
Stefano Cicale', Rome, IT;
Claudia Rocchi, Rome, IT;
Giuseppe Abbruzzese, Rome, IT;
Thyssenkrupp Acciai Speciali Terni S.p.A., Terni, IT;
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 600 cm<Iz<1500 cmand Iy=1.9 Fv/r (cm), Fv being the volume fraction of second phases stable at temperatures of less than 800° 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° 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° 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.