Patent US3870574A successfully refreshed from Google Patents.
US3870574A
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Two stage heat treatment process for the production of unalloyed, cold-rolled electrical steel
Assignee: CSEPEL MUEVEK FEMMUEVE
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Filing: 1972-10-05
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Granted: 1975-03-11
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Expires: 1992-10-05
Abstract
Abstract A process for the production of unalloyed electro-technical steel strip of improved magnetic and mechanical properties, in which low carbon steel having not more than 0.10 percent carbon is hot-rolled to produce hot-rolled strip covered with hotrolling scale. The scale is then covered with an inorganic hydroxide or carbonate and the strip is heated to 700* and 950*C. for a time sufficient to reduce the carbon content to not more than 0.01 percent. The decarburized strip is pickled, cold rolled to its final gauge, and then subjected to a special two-stage final heat treatment in the first stage of which the temperature is 350* to 600*C., preferably 460* to 490*C., and in the second stage of which the temperature is 600* to 780*C., preferably 680* to 760*C.
Inventors
- 👤 Mihaly Stefan
- 👤 Zoltan Hegedus
- 👤 Fulop Balazs
- 👤 Gyula Juhasz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:22
CPC Classifications
C; C21; C21D; C21D1/00; C21D1/74; C21D1/68; C21D1/72; C21D8/00; C21D8/12; C21D8/1277; C21D8/1283
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
139 words
A PROCESS FOR THE PRODUCTION OF UNALLOYED ELECTROTECHNICAL STEEL STRIP OF IMPROVED MAGNETIC AND MECHANICAL PROPERTIES, CONSISTING OF HOT ROLLING LOW CARBON STEEL HAVING NOT MORE THAT 0.10 PERCENT CARBON TO PRODUCE HOT-ROLLED STRIP COVERED WITH HOT-ROLLING SCALE, THEN COVERING SAID SCALE WITH A LAYER OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROXIDE, ALKALINE EARTH METAL HYDROXIDE, ALKALINE EARTH METAL CARBONATE, ALUMINUM HYDROXIDE AND A MIXTURE THEREOF, THEN HEATING THE STRIP WITH COVERED SCALE TO 700* TO 950*C. FOR A TIME SUFFICIENT TO REDUCE THE CARBON CONTENT TO NOT MORE THAN 0.01 PERCENT, THEN PICKLING AND COLD ROLLING TO ITS FINAL GUAGE THE DECARBURIZED STRIP, AND THEREAFTER HEATING THE STRIP IN A FIRST STAGE TO 350* TO 600*C. FOR ABOUT 2 HOURS AND IN A SECOND STAGE TO 600* TO 780*C. FOR ABOUT 0.5 HOUR.
Claim 2
Dependent Claim
139 words
A PROCESS FOR THE PRODUCTION OF UNALLOYED ELECTROTECHNICAL STEEL STRIP OF IMPROVED MAGNETIC AND MECHANICAL PROPERTIES, CONSISTING OF HOT ROLLING LOW CARBON STEEL HAVING NOT MORE THAT 0.10 PERCENT CARBON TO PRODUCE HOT-ROLLED STRIP COVERED WITH HOT-ROLLING SCALE, THEN COVERING SAID SCALE WITH A LAYER OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ALKALI METAL HYDROXIDE, ALKALINE EARTH METAL HYDROXIDE, ALKALINE EARTH METAL CARBONATE, ALUMINUM HYDROXIDE AND A MIXTURE THEREOF, THEN HEATING THE STRIP WITH COVERED SCALE TO 700* TO 950*C. FOR A TIME SUFFICIENT TO REDUCE THE CARBON CONTENT TO NOT MORE THAN 0.01 PERCENT, THEN PICKLING AND COLD ROLLING TO ITS FINAL GUAGE THE DECARBURIZED STRIP, AND THEREAFTER HEATING THE STRIP IN A FIRST STAGE TO 350* TO 600*C. FOR ABOUT 2 HOURS AND IN A SECOND STAGE TO 600* TO 780*C. FOR ABOUT 0.5 HOUR.
Claim 3
Dependent Claim
139 words
A process for the production of unalloyed electro-technical steel strip of improved magnetic and mechanical properties, consisting of hot rolling low carbon steel having not more than 0.10 percent carbon to produce hot-rolled strip covered with hot-rolling scale, then covering said scale with a layer of a member selected from thE group consisting of alkali metal hydroxide, alkaline earth metal hydroxide, alkaline earth metal carbonate, aluminum hydroxide and a mixture thereof, then heating the strip with covered scale to 700* to 950*C. for a time sufficient to reduce the carbon content to not more than 0.01 percent, then pickling and cold rolling to its final gauge the decarburized strip, and thereafter heating the strip in a first stage to 350* to 600*C. for about 2 hours and in a second stage to 600* to 780*C. for about 0.5 hour.
Claim 4
Dependent Claim
139 words
A process for the production of unalloyed electro-technical steel strip of improved magnetic and mechanical properties, consisting of hot rolling low carbon steel having not more than 0.10 percent carbon to produce hot-rolled strip covered with hot-rolling scale, then covering said scale with a layer of a member selected from thE group consisting of alkali metal hydroxide, alkaline earth metal hydroxide, alkaline earth metal carbonate, aluminum hydroxide and a mixture thereof, then heating the strip with covered scale to 700* to 950*C. for a time sufficient to reduce the carbon content to not more than 0.01 percent, then pickling and cold rolling to its final gauge the decarburized strip, and thereafter heating the strip in a first stage to 350* to 600*C. for about 2 hours and in a second stage to 600* to 780*C. for about 0.5 hour.
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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) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |