Steel sheet for tension mask, manufacturing method of steel sheet for tension mask, tension mask and cathode ray tube
AssigneeJfe Steel Corporation
InventorsHideki Matsuoka, Yasushi Tanaka, Reiko Sugihara, Tatsuhiko Hiratani, Kenichiro Takayanagi, Masamichi Okada, Hiroaki Kato
Life of this patent
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Abstract
A steel sheet for a tension mask excellent in the shielding properties from geomagnetism consists essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N and the balance of Fe, and has an anhysteretic magnetic permeability of 5,000 or higher.
Claims12
A steel sheet for a tension mask exhibiting excellent geomagnetic shielding properties, said steel sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C. for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
A steel sheet for a tension mask exhibiting excellent geomagnetic shielding properties and sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, higher than 0.6% and not higher than 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, not lower than 0.006% and lower than 0.01% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C. for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
A steel sheet for a tension mask exhibiting excellent geomagnetic shielding properties, said steel sheet being manufactured by the method comprising the steps of:
- obtaining a steel piece consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N, and the balance of Fe;
- hot rolling said steel piece;
- cold rolling once or a plurality of times the hot-rolled steel sheet with or without an intermediate annealing treatment interposed between the adjacent cold rolling processes so as to prepare a steel sheet having a predetermined thickness;
- and
- annealing the resultant steel sheet under a temperature region not higher than the recrystallization temperature so as to increase the anhysteretic magnetic permeability, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C. for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
A steel sheet for a tension mask exhibiting excellent geomagnetic shielding properties and excellent creep resistance under high temperatures, said steel sheet being manufactured by the method comprising the steps of:
- obtaining a steel piece consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, higher than 0.64 and not higher than 2% by weight of Mn, not higher than 0.1% by weight of P. not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, not lower than 0.006% and lower than 0.01% by weight of N, and the balance of Fe;
- hot rolling said steel piece;
- cold rolling once or a plurality of times the hot-rolled steel sheet with or without an intermediate annealing treatment interposed between the adjacent cold rolling processes so as to prepare a steel sheet having a predetermined thickness;
- and
- annealing the resultant steel sheet under a temperature region not higher than the recrystallization temperature so as to increase the anhysteretic magnetic permeability, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C. for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
In a tension mask formed of a steel sheet, the improvement comprising the steel sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher. said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
In a tension mask formed of a steel sheet, the improvement comprising the steel sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, higher than 0.6% and not higher than 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, not lower than 0.006% and lower than 0.01% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C. for 20 minutes with a tension of 300 N mm2 being applied to said steel sheet.
A cathode ray tube comprising a tension mask formed of a steel sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, 0.4 to 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, 0.003 to 0.02% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
A cathode ray tube comprising a tension mask formed of a steel sheet consisting essentially of lower than 0.1% by weight of C, lower than 0.2% by weight of Si, higher than 0.6% and not higher than 2% by weight of Mn, not higher than 0.1% by weight of P, not higher than 0.03% by weight of S, not higher than 0.01% by weight of sol. Al, not lower than 0.006% and lower than 0.01% by weight of N, and the balance of Fe, and having an anhysteretic magnetic permeability of 5,000 or higher, said steel sheet having a creep elongation of 0.50% or smaller, measured when said steel is maintained at a temperature of 450° C for 20 minutes with a tension of 300 N/mm2 being applied to said steel sheet.
Dependencies are inferred from the claim text.