Magnesium-aluminum coated steel sheet

Patent metadata

Field	Value
Publication number	US-10106866-B2
Application number	US-201415108260-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Dec 24, 2013
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

An exemplary embodiment of the present invention provides a coated steel sheet on which a magnesium-aluminum alloy coating layer is formed, including: a steel sheet; and a coating layer configured to include a first magnesium-aluminum alloy layer formed on a top surface of the steel sheet and a second magnesium-aluminum alloy layer formed on a top surface of the first magnesium-aluminum alloy layer, wherein a magnesium content of the first magnesium-aluminum alloy layer is higher than that of the second magnesium-aluminum alloy layer.

First claim

The invention claimed is:

1. A coated steel sheet on which a magnesium-aluminum alloy coating layer is formed, the coated steel sheet comprising:
a steel sheet; and
a coating layer configured to include a first magnesium-aluminum alloy layer formed on a top surface of the steel sheet and a second magnesium-aluminum alloy layer formed on a top surface of the first magnesium-aluminum alloy layer,
wherein a magnesium content of the first magnesium-aluminum alloy layer as a wt % of the first magnesium-aluminum alloy layer is higher than that of the second magnesium-aluminum alloy layer as a wt % of the second magnesium-aluminum alloy layer,
wherein the second magnesium-aluminum alloy layer contains columnar crystals,
wherein the magnesium content of the first magnesium-aluminum alloy layer is in a range of 20 to 95 wt %, and the magnesium content of the second magnesium-aluminum alloy layer is in a range of 5 to 40 wt %,
wherein a total magnesium content of the coating layer formed by the first magnesium-aluminum alloy layer and the second magnesium-aluminum alloy layer is equal to or greater than 12.5 wt %, and
wherein each of the first magnesium-aluminum alloy layer and the second magnesium-aluminum alloy layer has a thickness in a range of 0.5 to 30 μm.

2. The coated steel sheet of claim 1 , wherein a total thickness of the coating layer formed on the steel sheet by the first magnesium-aluminum alloy layer and the second magnesium-aluminum alloy layer is in a range of 1 to 50 μm.

3. The coated steel sheet of claim 1 , wherein a total thickness of the coating layer formed on the steel sheet by the first magnesium-aluminum alloy layer and the second magnesium-aluminum alloy layer is equal to or smaller than 5 μm.

4. A coated steel sheet on which a magnesium-aluminum alloy coating layer is formed, the coated steel sheet comprising:
a steel sheet; and
a coating layer configured to include a first magnesium-aluminum alloy layer formed on a top surface of the steel sheet and a second magnesium-aluminum alloy layer formed on a top surface of the first magnesium-aluminum alloy layer,
wherein a magnesium content of the first magnesium-aluminum alloy layer as a wt % of the first magnesium-aluminum alloy layer is higher than that of the second magnesium-aluminum alloy layer as a wt % of the second magnesium-aluminum alloy layer, and
wherein the coating layer contains a mixture of α-phase Al and β-phase Al 3 Mg 2 .

5. The coated steel sheet of claim 4 , wherein a part or all of the coating layer is formed to have a crystal grain shape.

6. The coated steel sheet of claim 5 , wherein each of the α-phase Al and the β-phase Al 3 Mg 2 forms crystal grains, and an average size of the crystal grains is in a range of 0.1 to 2 μm.

7. The coated steel sheet of claim 6 , wherein an area ratio of β-phase/α-phase of the coating layer crystal grain is in a range of 10 to 70%.

8. The coated steel sheet of claim 7 , wherein a ratio of α- and β-phases is in a range of 0.01 to 1.5 as an XRD intensity ratio, which is Iβ(880)/Iα(111).

Assignees

• Posco
• Res Inst Ind Science & Tech

Inventors

• Jeong Jae In
• Yang Ji Hoon
• Kim Tae Yeob
• Jung Yong Hwa

Classifications

• C23C14/025

  Metallic sublayers · CPC title

• Y10T428/12979

  Containing more than 10% nonferrous elements [e.g., high alloy, stainless] · CPC title

• Y10T428/24942

  including components having same physical characteristic in differing degree · CPC title

• C23C30/005

  on hard metal substrates · CPC title

• C23C14/5806

  Thermal treatment · CPC title