EP 0416420 A3 19921119 - MAGNESIUM OXIDE COATING FOR ELECTRICAL STEELS AND THE METHOD OF COATING
Title (en)
MAGNESIUM OXIDE COATING FOR ELECTRICAL STEELS AND THE METHOD OF COATING
Publication
Application
Priority
US 40471489 A 19890908
Abstract (en)
[origin: EP0416420A2] Decarburized grain oriented silicon steel is provided with an annealing separator which forms a glass film after the final high temperature anneal. The magnesia used as the annealing separator has a total chlorine level of 0.01 to 0.20% by weight based on the weight of magnesia with at least 0.01% metal chloride selected from the group of Mg, Ca, Na and K. The chloride addition acts to seal the coating surface during the final anneal to control diffusion and stabilize the secondary grain growth. The glass film which forms during the anneal may be laser scribed for domain refinement without coating damage. The magnesia may also contain additions of phosphates, TiO2, SiO2, Cr and B. The temperature of the magnesia is maintained below 25 DEG C to control hydration and eliminate the need for other additives in the magnesia slurry to control hydration.
IPC 1-7
IPC 8 full level
C23C 22/00 (2006.01); C21D 8/12 (2006.01); C21D 9/46 (2006.01); H01F 1/16 (2006.01); C21D 3/04 (2006.01)
CPC (source: EP KR)
C21D 1/70 (2013.01 - KR); C21D 8/12 (2013.01 - KR); C21D 8/1283 (2013.01 - EP); C21D 3/04 (2013.01 - EP)
Citation (search report)
- [X] EP 0305966 A1 19890308 - NIPPON STEEL CORP [JP]
- [A] FR 2399485 A1 19790302 - ARMCO INC [US]
- [A] US 4032366 A 19770628 - CHOBY JR EDWARD G
- [A] US 4190469 A 19800226 - ICHIDA TOSHIO [JP], et al
- [AD] US 3841925 A 19741015 - STEGER J
- [AD] US 3956029 A 19760511 - YAMAMOTO TAKAAKI, et al
- [A] PATENT ABSTRACTS OF JAPAN vol. 3, no. 68 (C-48)13 June 1979 & JP-A-54 041 220 ( SHIN NIPPON SEITETSU ) 2 April 1979
- [A] PATENT ABSTRACTS OF JAPAN vol. 3, no. 152 (C-67)14 December 1979 & JP-A-54 128 928 ( SHIN NIPPON SEITETSU ) 5 October 1979
- [A] PATENT ABSTRACTS OF JAPAN vol. 9, no. 237 (C-305)(1960) 24 September 1985 & JP-A-60 096 770 ( SHIN NIPPON SEITETSU ) 30 May 1985
Designated contracting state (EPC)
AT BE CH DE DK ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
EP 0416420 A2 19910313; EP 0416420 A3 19921119; EP 0416420 B1 19941214; BR 9004444 A 19910910; CA 2024226 A1 19910309; CA 2024226 C 20000215; DE 69015060 D1 19950126; DE 69015060 T2 19950427; JP 2686455 B2 19971208; JP H03120376 A 19910522; KR 0173781 B1 19990218; KR 910006518 A 19910429
DOCDB simple family (application)
EP 90116384 A 19900827; BR 9004444 A 19900906; CA 2024226 A 19900829; DE 69015060 T 19900827; JP 23599290 A 19900907; KR 900014201 A 19900908