Metal-coated steel strip

Patent metadata

Field	Value
Publication number	US-10233518-B2
Application number	US-43960507-A
Country	US
Kind code	B2
Filing date	Aug 30, 2007
Priority date	Aug 30, 2006
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

A steel strip having a coating of an aluminium-zinc-silicon alloy on at least one surface of the strip is disclosed. The strip is characterised in that the aluminium-zinc-silicon alloy contains less than 1.2 wt. % silicon and also contains magnesium. A method of forming a coating of an aluminium-zinc-silicon alloy on a steel strip is also disclosed. The method includes moving steel strip upwardly through a coating pot containing a bath of an aluminium-zinc-silicon alloy and having an opening in a bottom wall of the pot and forming a coating of the alloy on the strip. The method is characterized by minimizing residence time of steel strip in contact with the aluminium-zinc-silicon alloy bath in the pot.

First claim

What is claimed is:

1. A steel strip having a coating of an aluminum-zinc-silicon alloy on at least one surface of the strip which is characterized in that the aluminum-zinc-silicon alloy contains at least 0.2 wt. % and less than 1.0 wt. % silicon, between 1.5 and 2.5 wt. % magnesium, 37-46 wt. % Zn and 45-60 wt. % aluminium, wherein the aluminium-zinc-silicon alloy contains strontium and/or calcium, and the coating has small spangles that are less than 0.5 mm, and wherein the aluminum-zinc-silicon alloy is a titanium diboride-modified alloy; wherein the aluminium-zinc-silicon alloy does not contain vanadium and/or chromium as deliberate alloy elements—as opposed to being present in trace amounts.

2. The steel strip defined in claim 1 wherein the aluminum-zinc-silicon alloy contains 0.2-0.5 wt. % silicon.

3. The steel strip defined in claim 1 , wherein the titanium diboride-modified aluminum-zinc-silicon alloy contains up to 0.5 wt. % boron as titanium diboride.

4. A steel strip having a coating of an aluminum-zinc-silicon alloy on at least one surface of the strip which is characterized in that the aluminum-zinc-silicon alloy contains at least 0.2 wt. % and less than 1.0 wt. % silicon, between 1.5 and 2.5 wt. % magnesium, 37-46 wt. % Zn and 45-60 wt. % aluminium, wherein the aluminium-zinc-silicon alloy contains strontium and/or calcium, and the coating has small spangles that are less than 0.5 mm, wherein the aluminum-zinc-silicon alloy does not contain vanadium and/or chromium as deliberate alloy elements—as opposed to being present in trace amounts.

5. The steel strip defined in claim 4 wherein the aluminum-zinc-silicon alloy contains 0.2-0.5 wt. % silicon.

Assignees

• Liu Qiyang
• Williams Joe
• Smith Ross Mcdowall
• Bluescope Steel Ltd

Inventors

• Liu Qiyang
• Williams Joe
• Smith Ross Mcdowall

Classifications

• B32B15/012

  one layer being formed of an iron alloy or steel, another layer being formed of aluminium or an aluminium alloy · CPC title

• C23C2/02

  Pretreatment of the material to be coated, e.g. for coating on selected surface areas (C23C2/30 takes precedence) · CPC title

• Y10T428/12757

  Fe · CPC title

• C23C2/06

  Zinc or cadmium or alloys based thereon · CPC title

• C22C21/10 Primary

  with zinc as the next major constituent · CPC title