Patent US3873381A successfully refreshed from Google Patents.
US3873381A
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High permeability cube-on-edge oriented silicon steel and method of making it
Assignee: Armco Inc
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Filing: 1973-03-01
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Granted: 1975-03-25
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Expires: 1993-03-01
Abstract
Abstract Cube-on-edge oriented silicon steel and method of making it wherein the silicon steel is characterized by high permeability values. To the standard melt chemistry for cube-on-edge oriented silicon steel from about 0.002 to about 0.012 percent boron and from about 0.003 to about 0.010 percent nitrogen are added. The melt material is cast into ingots or slabs, reheated, hot rolled to hot band, annealed, pickled, cold reduced to final gauge, subjected to a decarburizing step and given a final high temperature anneal to produce the desired final orientation. The temperature of the anneal following hot rolling bears an inverse relationship to the final gauge of the silicon steel. Prior to the final anneal the silicon steel is provided with an annealing separator. A grain growth inhibitor may be provided in the environment of the stock during the primary grain growth stage of the final anneal so as to inhibit primary grain growth and to favor the growth of cube-on-edge oriented nuclei during the secondary grain growth stage.
Inventors
- 👤 John M Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:53
CPC Classifications
C; C21; C21D; C21D8/00; C21D8/12; C21D1/00; C21D1/68; C21D1/70; C22; C22C; C22C38/00; C22C38/02; C21D8/1244; C21D8/1261; C21D8/1272; C21D8/1277; C21D8/1283
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
218 words
A METHOD OF MAKING CUBE-ON-EDGE ORIENTED SILICON STEEL COMPRISING THE STEPS OF PREPARING A SILICON STEEL MELT HAVING A COMPOSITION IN WEIGHT PERCENT CONSISTING ESSENTIALLY OF FROM ABOUT 2 TO ABOUT 4 PERCENT SILICON, FROM ABOUT 01 TO ABOUT 0.15 PERCENT MANGANESE, FROM ABOUT 0.02 TO ABOUT 0.05 PERCENT CARBON, FROM ABOUT 0.01 TO ABOUT 0.03 PERCENT SULFUR, FROM ABOUT 0.003 TO ABOUT 0.010 PERCENT BORON, FROM ABOUT 0.003 TO ABOUT 0.010 PERCENT NITROGEN, UP TO 0.008 PERCENT ALUMINUM, THE BALANCE BEING IRON AND IMPURITES INCIDENT TO THE MODE OF MANUFACTURE, CASTING SAID SILICON STEEL MELT, REHEATING SAID SILICON STEEL AT A TEMPERATURE OF FROM ABOUT 2,300*F TO ABOUT 2,550*F, HOT ROLLING SAID SILICON STEEL TO AN INTERMEDIATE THICKNESS OF FROM ABOUT 0.050 TO ABOUT 0.100 IN., ANNEALING SAID HOT ROLLED SILICON STEEL AT A TEMPERATURE OF FROM ABOUT 1,500*F TO ABOUT 2,100*F, PICKLING SAID ANNEALED SILICON STEEL AND COLD REDUCING IT TO FINAL GAUGE, GAUGE, DECARBURIZING S COLD REDUCED SILICON STEEL, PROVIDING AN ANNEALING SEPARATOR FOR SAID DECARBURIZED SILICON STEEL AND SUBJECTING SAID SILICON STEEL TO A FINAL BOX ANNEAL IN DRY HYDROGEN AT ATEMPERATURE OF FROM ABOUT 2000*F TO ABOUT 2,300*F FOR FROM ABOUT 8 TO ABOUT 30 HOURS, WHEREBY TO PROVIDE A CUBE-ON-EDGE ORIENTED SILICON STEEL HAVING A PERMEABILITY AT H=10 OERSTEDS GREATER THAN 1820.
Claim 2
Independent Claim
218 words
A METHOD OF MAKING CUBE-ON-EDGE ORIENTED SILICON STEEL COMPRISING THE STEPS OF PREPARING A SILICON STEEL MELT HAVING A COMPOSITION IN WEIGHT PERCENT CONSISTING ESSENTIALLY OF FROM ABOUT 2 TO ABOUT 4 PERCENT SILICON, FROM ABOUT 01 TO ABOUT 0.15 PERCENT MANGANESE, FROM ABOUT 0.02 TO ABOUT 0.05 PERCENT CARBON, FROM ABOUT 0.01 TO ABOUT 0.03 PERCENT SULFUR, FROM ABOUT 0.003 TO ABOUT 0.010 PERCENT BORON, FROM ABOUT 0.003 TO ABOUT 0.010 PERCENT NITROGEN, UP TO 0.008 PERCENT ALUMINUM, THE BALANCE BEING IRON AND IMPURITES INCIDENT TO THE MODE OF MANUFACTURE, CASTING SAID SILICON STEEL MELT, REHEATING SAID SILICON STEEL AT A TEMPERATURE OF FROM ABOUT 2,300*F TO ABOUT 2,550*F, HOT ROLLING SAID SILICON STEEL TO AN INTERMEDIATE THICKNESS OF FROM ABOUT 0.050 TO ABOUT 0.100 IN., ANNEALING SAID HOT ROLLED SILICON STEEL AT A TEMPERATURE OF FROM ABOUT 1,500*F TO ABOUT 2,100*F, PICKLING SAID ANNEALED SILICON STEEL AND COLD REDUCING IT TO FINAL GAUGE, GAUGE, DECARBURIZING S COLD REDUCED SILICON STEEL, PROVIDING AN ANNEALING SEPARATOR FOR SAID DECARBURIZED SILICON STEEL AND SUBJECTING SAID SILICON STEEL TO A FINAL BOX ANNEAL IN DRY HYDROGEN AT ATEMPERATURE OF FROM ABOUT 2000*F TO ABOUT 2,300*F FOR FROM ABOUT 8 TO ABOUT 30 HOURS, WHEREBY TO PROVIDE A CUBE-ON-EDGE ORIENTED SILICON STEEL HAVING A PERMEABILITY AT H=10 OERSTEDS GREATER THAN 1820.
Claim 3
Dependent Claim
77 words
The process claimed in claim 1 wherein said melt composition in percent by weight consists essentially of from about 2 to about 4 percent silicon, from about 0.03 to about 0.15 percent manganese, from about 0.02 to about 0.05 percent carbon, from about 0.01 to about 0.03 percent sulfur, from about 0.003 to about 0.010 percent boron, from about 0.004 to about 0.008 percent nitrogen, the balance being iron and impurities incident to the mode of manufacture.
Claim 4
Dependent Claim
58 words
The process claimed in claim 1 wherein said final anneal has a primary grain growth stage and a secondary grain growth stage, providing a grain growth inhibitor in the environment of said silicon steel during said primary grain growth stage, said grain growth inhibitor being chosen from the class consisting of sulfur, sulfur compounds, selenium and selenium compounds.
Claim 5
Dependent Claim
24 words
The process claimed in claim 1 wherein said annealing separator comprises magnesia containing from about 1 percent to about 6 percent sulfur by weight.
Claim 6
Dependent Claim
37 words
The process claimed in claim 1 wherein said final box anneal has a heat-up period, said heat-up period being conducted in a nitrogen atmosphere, the remainder of said box annealing being conducted in said dry hydrogen atmosphere.
Claim 7
Dependent Claim
41 words
The process claimed in claim 1 wherein said anneal following said hot rolling is conducted at a temperature of from about 1, 700*F to about 2,000*F, said temperature range bearing an inverse relationship to said final gauge of said silicon steel.
Claim 8
Dependent Claim
18 words
The process claimed in claim 2 wherein said melt contains about 0.007 boron and about 0.007 percent nitrogen.
Claim 9
Dependent Claim
108 words
The process claimed in claim 2 wherein said anneal following said hot rolling is conducted at a temperature of from about 1, 700*F to about 2,000*F, said last mentioned temperature range bearing an inverse relationship to said final gauge of said silicon steel, said annealing separator comprising magnesia containing from about 1 percent to about 6 percent sulfur by weight, said final anneal having a heat-up stage, said heat-up stage being conducted with a nitrogen atmosphere, the remainder of said final box anneal being conducted in said dry hydrogen atmosphere, the temperature of said heat-up stage being raised at the rate of less than about 125*F per hour.
Claim 10
Dependent Claim
36 words
The process claimed in claim 5 wherein said final box anneal has a heat-up stage, said temperature of said final anneal being raised during said heat-up stage at the rate of less than 125* per hour.
Claim 11
Dependent Claim
25 words
A cube-on-edge oriented silicon steel having a permeability at H 10 oersteds greater than 1,820 and made in accordance with the process of claim 1.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |