Aluminum-coated structural member and production method
First Claim
Patent Images
1. An aluminum-coated structural member comprising:
- a steel substrate layer; and
an Al—
Si—
Fe alloy layer formed on a surface of the steel substrate layer, the alloy layer including a softer region having a hardness smaller than or equal to a hardness of the steel substrate layer, extending from the surface of the steel substrate layer toward a surface of the alloy layer, and having a thickness greater than or equal to 50% of a thickness of the alloy layer, the Al—
Si—
Fe alloy layer having an oxide weight smaller than or equal to 500 mg/dm2.
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Abstract
An aluminum-coated structural member includes an Al—Si—Fe alloy layer formed on a steel substrate layer. The alloy layer includes a softer region having a hardness smaller than or equal to a hardness of the steel substrate layer, extends from the surface of the steel substrate layer toward a surface of the alloy layer, over a depth range greater than or equal to 50% of a thickness of the alloy layer. The Al—Si—Fe alloy layer has an oxide weight smaller than or equal to 500 mg/dm2.
26 Citations
10 Claims
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1. An aluminum-coated structural member comprising:
-
a steel substrate layer; and
an Al—
Si—
Fe alloy layer formed on a surface of the steel substrate layer, the alloy layer including a softer region having a hardness smaller than or equal to a hardness of the steel substrate layer, extending from the surface of the steel substrate layer toward a surface of the alloy layer, and having a thickness greater than or equal to 50% of a thickness of the alloy layer, the Al—
Si—
Fe alloy layer having an oxide weight smaller than or equal to 500 mg/dm2. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An aluminum-coated structural member comprising:
-
a steel substrate layer; and
an Al—
Si—
Fe alloy layer formed on a surface of the steel substrate layer, the Al—
Si—
Fe alloy layer having a multi-layer structure including an inner layer contiguous with the steel substrate layer, an outer layer forming a surface of the alloy layer and an intermediate layer formed between the inner and outer layers, the inner layer containing 85˜
95% Fe, the intermediate layer containing 25˜
40% Al, and the outer layer being harder than the steel substrate layer.
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10. A production method of an aluminum-coated structural member comprising:
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heating a hot-dip aluminum-coated steel sheet at a heating rate in a range of 1˜
10°
C./sec;
holding the hot-dip aluminum steel sheet at a raised temperature in a temperature range of 900˜
950°
C. for a duration in a range of 2˜
8 minutes;
cooling the hot-dip aluminum-coated steel sheet to a temperature in a temperature range of 700˜
800°
C. at a cooling rate in a range of 5˜
15°
C./sec;
forming the hot-dip aluminum-coated steel sheet into a predetermined shape in the temperature range of 700˜
800°
C.; and
cooling the hot-dip aluminum-coated steel sheet in the predetermined shape rapidly from the temperature range of 700˜
800°
C. to a lower temperature lower than or equal to 300°
C. at a cooling rate in a range of 20˜
100°
C./sec.
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Specification