Steel sheet coated with aluminum-magnesium, and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2016194737-A1
Application number	US-201314758192-A
Country	US
Kind code	A1
Filing date	Dec 24, 2013
Priority date	Dec 26, 2012
Publication date	Jul 7, 2016
Grant date	—

Abstract

The present invention relates to an aluminum-magnesium coated steel plate using vacuum coating, wherein an aluminum-magnesium coating layer is constituted by 1 to 45 wt % of magnesium, a balance of aluminum, and other inevitable impurities, and an Al 3 Mg 2 alloy phase is formed in the aluminum-magnesium coating layer by performing heat treatment of the steel plate.

First claim

1 . A steel plate having an aluminum-magnesium alloy layer, comprising:
a steel plate; an aluminum-iron alloy layer formed on an upper portion of the steel plate; and the aluminum-magnesium alloy layer formed on an upper portion of the aluminum-iron alloy layer, wherein the aluminum-magnesium alloy layer includes 1 to 45 wt % of magnesium based on an entire alloy layer.

2 . (canceled)

3 . The steel plate of claim 1 , wherein in the aluminum-magnesium alloy layer, an α phase and a β phase (Al3Mg2) are mixed.

4 . The steel plate of claim 3 , wherein the aluminum-iron alloy layer is formed in a thickness that is 1 to 50% of a thickness of the entire alloy layer in a direction of the alloy layer in the steel plate.

5 . The steel plate of claim 4 , wherein in the aluminum-iron alloy layer, an iron component of the steel plate is diffused into a coating layer to form an AlxFey layer, and the AlxFey layer satisfies the following conditions:
in the AlxFey layer, x is 1 to 3 and y is 0.5 to 1.5.

6 . The steel plate of claim 5 , wherein a thickness of the aluminum-iron alloy layer is 0.2 to 1 μm.

7 . The steel plate of claim 1 , wherein the aluminum-magnesium alloy layer is formed in a crystal grain form.

8 . The steel plate of claim 7 , wherein a thickness of the aluminum-magnesium alloy layer is 0.5 to 30 μm.

9 . The steel plate of claim 8 , wherein crystal grains of the aluminum-magnesium alloy layer are formed by an α phase and a β phase (Al3Mg2), and an average grain diameter of the crystal grains is 0.1 to 2 μm.

10 . The steel plate of claim 9 , wherein in the aluminum-magnesium alloy layer, an area ratio of the β phase/α phase of the crystal grain is 10 to 70%.

11 . The steel plate of claim 10 , wherein an XRD intensity ratio Iβ (880)/Iα (111) of the α phase and the β phase of the aluminum-magnesium alloy layer is 0.01 to 1.5.

12 . A method of forming an aluminum-magnesium alloy layer on a steel plate, comprising:
preparing the steel plate; vacuum depositing an aluminum coating layer on an upper portion of the steel plate; vacuum depositing a magnesium coating layer on an upper portion of the aluminum coating layer at least one time or more; and vacuum depositing a secondary aluminum coating layer on an upper portion of the magnesium coating layer at least one time or more; wherein the steel plate where the aluminum-magnesium coating layer is formed is subjected to heat treatment in a heat treatment furnace to perform phase transformation of the aluminum-magnesium coating layer into the aluminum-magnesium alloy layer.

13 . (canceled)

14 . The method of claim 12 , wherein the magnesium coating layer instead of the aluminum coating layer is first vacuum deposited on the upper portion of the steel plate, and continuously, the aluminum coating layer and the magnesium coating layer are sequentially vacuum deposited repeatedly at least one time or more.

15 . The method of claim 12 , wherein the magnesium coating layer that is vacuum deposited on the steel plate is reacted with iron on the steel plate by diffusion of aluminum that is vacuum deposited on the upper portion of magnesium to be vacuum deposited in a thickness in which an iron-aluminum alloy layer is formed on the coating layer.

16 - 18 . (canceled)

19 . The method of claim 12 , wherein the aluminum-magnesium coating layer is vacuum deposited by magnetron sputtering.

20 . The method of claim 19 , wherein the aluminum-magnesium coating layer is vacuum deposited by repeatedly reciprocating the steel plate disposed on upper portions of an aluminum source and a magnesium source.

21 . The method of claim 20 , wherein a composition of the aluminum-magnesium coating layer is changed by changing a current or a voltage applied to the aluminum source and the magnesium source.

22 . (canceled)

23 . The method of claim 12 , wherein the heat treatment is performed under a condition of an inert atmosphere, a temperature in a range of 350 to 450° C., and a heat treatment time of 2 to 10 minutes.

24 . The method of claim 23 , wherein one or more of the iron-aluminum alloy layer or the aluminum-magnesium alloy layer is formed from the coating layer by the heat treatment.

25 . The method of claim 24 , wherein an iron component of the steel plate is diffused into the coating layer to form an AlxFey layer, and the AlxFey layer satisfies the following conditions:
in the AlxFey layer, x is 1 to 3 and y is 0.5 to 1.5.

26 . The method of claim 25 , wherein a thickness of the aluminum-iron alloy layer is 0.2 to 1 μm.

27 . (canceled)

Assignees

• Posco
• Res Inst Ind Science & Tech
• Res Inst Of Idustrial Science & Technology

Inventors

• Yang Ji Hoon
• Jeong Jae In
• Kim Tae-Yeob
• Jung Yonghwa

Classifications

• Y10T428/26

  Web or sheet containing structurally defined element or component, the element or component having a specified physical dimension · CPC title

• C23C14/025

  Metallic sublayers · CPC title

• Y10T428/2495

  Thickness [relative or absolute] · CPC title

• Y10T428/12729

  Group IIA metal-base component · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title