Process for coating discrete articles with a zinc-based alloyed layer and articles obtained therefrom

Patent metadata

Field	Value
Publication number	US-9623632-B2
Application number	US-201514711118-A
Country	US
Kind code	B2
Filing date	May 13, 2015
Priority date	Feb 4, 2009
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A vacuum deposition process suitable for coating discrete articles with a zinc-rich, fully alloyed layer is described. In a process step of contacting the article with metallic Zn vapor, the temperature of the article is equal to or higher than the dew point of the Zn vapor. The process results in a coating having a uniform thickness, even on less accessible surfaces. Additionally, the roughness of the steel substrate is essentially preserved. By properly engineering the surface of the substrate, coated articles can be obtained having a roughness providing for optimal paint adhesion.

First claim

The invention claimed is:

1. A galvannealed article comprising a steel substrate and a coating layer consisting of Zn—Fe intermetallics, the surface roughness of the substrate being defined by the parameters Ra and Rz, and the surface roughness of the coating layer being defined by the parameters Ra′ and Rz′, whereby 0.5≦Ra≦20 μm, 5≦Rz≦140 μm, 0.8≦Ra′/Ra≦1.3, 0.8≦Rz′/Rz≦1.3.

2. The galvannealed article according to claim 1 , additionally comprising a layer of paint.

3. The galvannealed article according to claim 1 , wherein the coating layer has a mean thickness of more than 10 μm.

4. The galvannealed article according to claim 2 , wherein the coating layer has a mean thickness of more than 10 μm.

Assignees

• Gay Bruno
• Petit Etienne
• Umicore Nv

Inventors

• Gay Bruno
• Petit Etienne

Classifications

• B32B15/013 Primary

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

• C23F17/00

  Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25 (coating for obtaining at least two superposed coatings either by methods not provided for in a single one of main groups C23C2/00 - C23C26/00, or by combinations of methods providedfor in subclasses C23C and C25D, C23C28/00) · CPC title

• C23C14/021

  Cleaning or etching treatments · CPC title

• C25D5/00

  Electroplating characterised by the process; Pretreatment or after-treatment of workpieces · CPC title

• C23C2/06

  Zinc or cadmium or alloys based thereon · CPC title