Al-PLATED STEEL SHEET USED FOR HOT PRESSING AND METHOD FOR MANUFACTURING Al-PLATED STEEL SHEET USED FOR HOT PRESSING

Patent metadata

Field	Value
Publication number	US-2016362794-A1
Application number	US-201415103152-A
Country	US
Kind code	A1
Filing date	Dec 10, 2014
Priority date	Dec 12, 2013
Publication date	Dec 15, 2016
Grant date	—

Abstract

[Object] To provide an Al-plated steel sheet used for hot pressing that has excellent lubricity in hot state, corrosion resistance after paint coating, and spot weldability.
[Solution] An Al-plated steel sheet used for hot pressing according to the present invention includes: a steel sheet; an Al plating layer formed on one surface or both surfaces of the steel sheet; and a surface coating layer formed on the Al plating layer. The surface coating layer contains a zinc compound, and the zinc compound is deposited on the Al-plated steel sheet in an amount of equal to or greater than 0.3 g/m 2 and equal to or less than 1.5 g/m 2 as an amount of metallic zinc per one surface, and a zinc deposition amount in any continuous 1 mm 2 region is 1.5 g/m 2 or less.

First claim

1 .- 10 . (canceled)

11 . An Al-plated steel sheet used for hot pressing, comprising:
a steel sheet; an Al plating layer formed on one surface or both surfaces of the steel sheet; and a surface coating layer formed on the Al plating layer, wherein the surface coating layer contains a zinc compound, and the zinc compound is deposited on the Al-plated steel sheet in an amount of equal to or greater than 0.3 g/m 2 and equal to or less than 1.5 g/m 2 as an amount of metallic zinc per one surface, and a zinc deposition amount in any continuous 1 mm 2 region is 1.5 g/m 2 or less.

12 . The Al-plated steel sheet used for hot pressing according to claim 11 ,
wherein the zinc compound in the surface coating layer is zinc oxide.

13 . The Al-plated steel sheet used for hot pressing according to claim 11 ,
wherein an average length RSm of a profile element in a roughness curve of a surface of the Al-plated steel sheet used for hot pressing after the formation of the surface coating layer is 500 μm or less.

14 . The Al-plated steel sheet used for hot pressing according to claim 12 ,
wherein an average length RSm of a profile element in a roughness curve of a surface of the Al-plated steel sheet used for hot pressing after the formation of the surface coating layer is 500 μm or less.

15 . A method for manufacturing an Al-plated steel sheet used for hot pressing, comprising the steps of:
applying an application liquid containing a zinc compound and having a contact angle of equal to or greater than 20° and equal to or less than 50° with respect to the Al-plated steel sheet onto the Al-plated steel sheet including a steel sheet and the Al plating layer formed on one surface or both surfaces of the steel sheet; and drying the Al-plated steel sheet onto which the application liquid has been applied, at a peak metal temperature of equal to or higher than 60° C. and equal to or lower than 200° C., to form a surface coating layer containing the zinc compound on the Al plating layer.

16 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein a surface tension of the application liquid at 25° C. is equal to or greater than 20 mN/m and equal to or less than 60 mN/m.

17 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein a viscosity of the application liquid at 25° C. is equal to or greater than 2 mPa·s and equal to or less than 20 mPa·s.

18 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 16 ,
wherein a viscosity of the application liquid at 25° C. is equal to or greater than 2 mPa·s and equal to or less than 20 mPa·s.

19 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein the application liquid is applied onto the Al plating layer with a roll coater.

20 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein the zinc compound is zinc oxide.

21 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein in the manufactured surface coating layer, the zinc compound is deposited on the Al-plated steel sheet in an amount of equal to or greater than 0.3 g/m 2 and equal to or less than 1.5 g/m 2 as an amount of metallic zinc per one surface, and a zinc deposition amount in any continuous 1 mm 2 region is 1.5 g/m 2 or less.

22 . The method for manufacturing an Al-plated steel sheet used for hot pressing according to claim 15 ,
wherein an average length RSm of a profile element in a roughness curve of a surface of the manufactured Al-plated steel sheet used for hot pressing after the formation of the surface coating layer is 500 μm or less.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Fujita Soshi
• Yamanaka Shintaro
• Maki Jun
• Fujimoto Hiroki
• Oikawa Hatsuhiko
• Irikawa Hideaki

Classifications

• C23C2/40

  Plates; Strips · CPC title

• C22C38/38

  with more than 1.5% by weight of manganese · CPC title

• C22C38/06

  containing aluminium · CPC title

• C22C21/00

  Alloys based on aluminium · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title