STEEL SHEET FOR INNER MAGNETIC SHIELD, ITS MANUFACTURING METHOD, AND INNER MAGNETIC SHIELD

摘要

PROBLEM TO BE SOLVED: To provide a steel sheet for inner magnetic shield by which geomagnetic drift quantity can be reduced and which has excellent geomagnetic shielding property and also to provide its manufacturing method and an inner shield.

SOLUTION: In the steel sheet for inner shield: the ratio between non- hysteresis permeability in a rolling direction and that in a direction perpendicular to the rolling direction is made to ≤0.7 or ≥1.4, preferably ≤0.5 or ≥2.0; and a higher value between these non-hysteresis permeability values is ≥18,000. The inner shield is composed of the above steel sheet and has a form which is like a nearly truncated quadrangular pyramid and in which respective planes of members are mutually joined at respective edges. Further, the direction of higher non-hysteresis permeability of the steel sheet is properly arranged in the horizontal-plane direction of the screen short-side members; or in addition, the direction of higher non-hysteresis permeability of the steel sheet is properly arranged in the horizontal-plane direction of the screen long-side members.

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