US4306922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electro magnetic steels
Assignee: ORB Electrical Steels Ltd
•
Filing: 1980-08-21
•
Granted: 1981-12-22
•
Expires: 2000-08-21
Abstract
Abstract A method for producing non-oriented steel for electromagnetic applications comprises hot rolling a steel containing a nitride/carbide former and coiling the hot band at a temperature of not less than 680° C. before cold reduction and annealing in a non-decarburizing atmosphere.
Inventors
- 👤 Alan Coombs
- 👤 James H. R. Page
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:51
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/12; C22; C22C; C22C38/00; C22C38/02; C22C38/14; C21D8/1216; C21D8/1222; C21D8/1244
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
124 words
A method for producing non-oriented steel sheet for electromagnetic applications which comprises hot rolling steel having less than 0.025% carbon, between 0.05% and 3.5% silicon, between 0.2% and 0.8% manganese, between 0.10% and 0.35% aluminium, between 0.003% and 0.008% nitrogen, together with a nitride/carbide former selected from the group consisting of titanium, niobium, tantalum, vanadium, and zirconium, the remainder being iron except for incidental impurities, coiling the hot band at a temperature of not less than 680° C. subsequently cold reducing the band and then subjecting the cold reduced material of substantially final gauge to a non-decarburising anneal at a temperature lying within the range 900° C. to 1000° C. whereby a structure having a large primary grain size essentially randomly oriented is developed.
Claim 2
Independent Claim
124 words
A method for producing non-oriented steel sheet for electromagnetic applications which comprises hot rolling steel having less than 0.025% carbon, between 0.05% and 3.5% silicon, between 0.2% and 0.8% manganese, between 0.10% and 0.35% aluminium, between 0.003% and 0.008% nitrogen, together with a nitride/carbide former selected from the group consisting of titanium, niobium, tantalum, vanadium, and zirconium, the remainder being iron except for incidental impurities, coiling the hot band at a temperature of not less than 680° C. subsequently cold reducing the band and then subjecting the cold reduced material of substantially final gauge to a non-decarburising anneal at a temperature lying within the range 900° C. to 1000° C. whereby a structure having a large primary grain size essentially randomly oriented is developed.
Claim 3
Dependent Claim
25 words
A method as claimed in claim 1 in which the non-decarburising final anneal is at a temperature within the range 940° C. to 1000° C.
Claim 4
Dependent Claim
24 words
A method as claimed in claim 2 wherein the non-decarburising final anneal is at a temperature within the range 950° C. to 1000° C.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 3 in which the steel is produced by any conventional steel making process.
Claim 6
Dependent Claim
34 words
A method as claimed in claim 4 wherein the steel is produced by basic oxygen or open hearth refining and is subject to vacuum degassing to reduce the carbon concentration to the selected level.
Claim 7
Independent Claim
28 words
A method as claimed in claims 1, 2, 3, 4 or 5 in which the hot band is hot rolled at a finishing temperature greater than 900° C.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 1 in which the hot band is coiled at a temperature greater than 700° C.
Claim 9
Dependent Claim
24 words
A method as claimed in claim 7 wherein the hot band is cold reduced to substantially final gauge in a single cold rolling operation.
Claim 10
Dependent Claim
28 words
A method as claimed in claim 7 wherein the hot band is cold reduced to substantially final gauge in two stages of cold rolling with an intermediate anneal.
Claim 11
Dependent Claim
23 words
A method as claimed in claim 9 wherein the intermediate anneal is at a temperature within the range 850° C. to 1000° C.
Claim 12
Dependent Claim
23 words
A method as claimed in claim 10 wherein the intermediate anneal is at a temperature within the range 900° C. to 1000° C.
Claim 13
Dependent Claim
17 words
A method as claimed in claim 9 in which the intermediate anneal is in a non-decarburising atmosphere.
Claim 14
Dependent Claim
38 words
A method as claimed in claim 1 wherein the concentration of nitride/carbide former is selected to lie within the range 0.05%-0.2% by weight for titanium, 0.06%-0.3% for vanadium, 0.05%-0.3% for niobium, 0.12%-0.3% for zirconium and 0.10%-0.3% for tantalum.
Claim 15
Dependent Claim
24 words
A method as claimed in claim 13 wherein the concentration by weight of phosphorus and sulphur is not greater than 0.04% and 0.025% respectively.
Claim 16
Dependent Claim
19 words
A method as claimed in claim 5 in which the nitride/carbide former is added during or after vacuum degassing.
References Cited (Backward Citations)
US2104169A
Cited
US2867558A
Cited
US2939810A
Cited
US3096222A
Cited
US3351501A
Cited
US3214303A
Cited
US3764407A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-21 | 1985-06-22 | 1985-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-21 | 1989-06-22 | 1989-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-21 | 1993-06-22 | 1993-12-22 | $7700.00 | Window Closed / Lapsed |