Al-plated steel sheet, method for hot-pressing Al-plated steel sheet, and automotive part

Patent metadata

Field	Value
Publication number	US-9821858-B2
Application number	US-201314382085-A
Country	US
Kind code	B2
Filing date	Apr 15, 2013
Priority date	Apr 18, 2012
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An Al-plated steel sheet includes: a steel sheet; an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and a surface coating layer which is laminated on the surface of the Al plating layer and contains ZnO and one or more lubricity improving compounds.

First claim

The invention claimed is:

1. An Al-plated steel sheet comprising:
a steel sheet;
an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and
a surface coating layer which is coated on the surface of the Al plating layer,
wherein:
the surface coating layer, formed on one surface of the steel sheet, contains 0.3 g/m 2 to 7 g/m 2 of ZnO in terms of Zn, and contains a lubricity improving compound including one or more transition metal elements selected from the group consisting of Ti, Mn, Ni, Cu and Zr,
said lubricity improving compound is a sulfated compound, a fluoride compound, or a nitric acid compound, and
an amount of said lubricity improving compound is 0.5% to 50% with respect to a total amount of ZnO by mass ratio.

2. The Al-plated steel sheet according to claim 1 ,
wherein the amount of said lubricity improving compound including the transition metal element in the surface coating layer is 1% to 40% with respect to the total amount of ZnO by mass ratio.

3. A method for hot-pressing an Al-plated steel sheet comprising:
blanking and then heating the Al-plated steel sheet according to claim 1 ; and
press-forming the steel sheet.

4. The method for hot-pressing an Al-plated steel sheet according to claim 3 ,
wherein an average temperature rising rate until the temperature of the Al-plated steel sheet reaches from 50° C. to a temperature 10° C. lower than a maximum reaching temperature is 10° C./sec to 300° C./sec in the heating before the press-forming of the steel sheet.

5. The method for hot-pressing an Al-plated steel sheet according to claim 4 ,
wherein the heating before the press-forming of the steel sheet is performed by electrical heating or induction heating.

6. An automotive part produced by the method for hot-pressing an Al-plated steel sheet according to claim 3 .

7. An Al-plated steel sheet comprising:
a steel sheet;
an Al plating layer which is formed on one surface or both surfaces of the steel sheet and contains at least 85% or more of Al by mass %; and
a surface coating layer which is coated on the surface of the Al plating layer,
wherein:
the surface coating layer, formed on one surface of the steel sheet, contains 0.3 g/m 2 to 7 g/m 2 of ZnO in terms of Zn, and contains a lubricity improving compound including one or more typical elements selected from the group consisting of Mg, Sr, Sn and Ge,
the lubricity improving compound is an oxide, and
an amount of said oxide is 3% to 35% with respect to a total amount of ZnO by mass ratio.

8. The Al-plated steel sheet according to claim 7 ,
wherein the amount of the oxide is 5% to 30% with respect to the total amount of ZnO by mass ratio.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Maki Jun
• Kurosaki Masao
• Kusumi Kazuhisa
• Yamanaka Shintaro

Classifications

• Y10T428/12611

  Oxide-containing component · CPC title

• Y10T428/12556

  Organic component · CPC title

• C23C28/345 Primary

  with at least one oxide layer · CPC title

• C23C28/321

  with at least one metal alloy layer · CPC title

• C23C24/085

  Coating with metallic material, i.e. metals or metal alloys, optionally comprising hard particles, e.g. oxides, carbides or nitrides · CPC title