Method for Producing a Sheet having a ZnAlMg Coating with Optimized Wiping and corresponding Sheet

Patent metadata

Field	Value
Publication number	US-2016340767-A1
Application number	US-201615229910-A
Country	US
Kind code	A1
Filing date	Aug 5, 2016
Priority date	Dec 20, 2013
Publication date	Nov 24, 2016
Grant date	—

Abstract

The present invention provides a method for producing a sheet. The method includes providing a substrate, depositing a metal coating over at least one surface by dipping the substrate in a bath in order to obtain the sheet, wiping the metal coating by means of at least one nozzle projecting through at least one outlet a wiping gas onto the metal coating, the sheet being run in front of the nozzle, the wiping gas being ejected from the nozzle along a primary direction of ejection (E), a confinement box delimiting a confined zone at least downstream of the zone of impact (I) of the wiping gas on the sheet and solidifying the metal coating. The method satisfying:

Z
d

≤

12



and




f

O
2

≤

10

-
4

W
2



(

0.63
+

0.4
+

94900
*



W
2

)




with



W

=

PdZ

V

.

First claim

What is claimed is:

1 . A method for producing a sheet comprising the steps of:
providing a substrate made of steel, the steel substrate including at least one surface coated with a metal coating comprising a content by weight of Al from 0.5% to 8% and a content by weight of Mg from 0.3% to 3.3%, a remainder of the metal coating comprising Zn and inevitable impurities; depositing the metal coating over at least one surface by dipping the substrate in a bath in order to obtain the sheet; wiping the metal coating with a wiping gas via at least one nozzle projecting through at least one outlet, the sheet being run in front of the nozzle, the wiping gas being ejected from the nozzle along a primary direction of ejection (E), a confinement box delimiting a confined zone at least downstream of a zone of impact (I) of the wiping gas on the sheet; and solidifying the metal coating, wherein

Z
d

≤

12



and




f

O
2

≤

10

-
4

W
2



(

0.63
+

0.4
+

94900
*



W
2

)





(
A
)

with



W

=

PdZ

V

,

Z being a distance between the sheet and the nozzle along a primary direction of ejection (E), Z being expressed in m,
f O 2 being a volume fraction of oxygen in the confined zone,
d being an average height of the outlet of the nozzle along a direction (S) of movement of the sheet running in front of the nozzle, d being expressed in m,
V being a speed of movement of the sheet running in front of the nozzle, V being expressed in ms −1 , and
P being an excess pressure of the wiping gas in the nozzle as compared to an atmospheric pressure, P being expressed in Nm −2 .

2 . The method according to claim 1 , further comprising the step of:
cold rolling the sheet prior to the step of depositing a coating.

3 . The method according to claim 1 , further comprising the step of:
skin-pass rolling the sheet after the step of solidifying the coating.

4 . The method according to claim 1 , wherein the content by weight of Al in the metal coating is from 0.5% to 3.9%.

5 . The method according to claim 4 , wherein the content by weight of Al in the metal coating is from 1.5% to 3.9%.

6 . The method according to claim 1 , wherein the content by weight of Al in the metal coating is from 4.4% to 5.6%.

7 . The method according to claim 1 , wherein the content by weight of Mg in the metal coating is from 1.0% to 3.3%.

8 . The method according to claim 7 , wherein the content by weight of Mg in the metal coating is from 2.5% to 3.3%.

9 . The method according to claim 1 , wherein the content by weight of Mg in the metal coating is from 0.3% to 1.5%.

10 . A sheet obtainable according to the method recited in claim 1 , the sheet comprising:
a substrate made of steel having at least one surface; and a metal coating on the at least one surface, the metal coating including:
a content by weight of Al from 0.5% to 8%;
a content by weight of Mg from 0.3% to 3.3%; and
a remainder of the metal coating comprising Zn and inevitable impurities.

11 . The sheet according to claim 10 , wherein the content by weight of Al in the metal coating is from 0.5% to 3.9%.

12 . The sheet according to claim 11 , wherein the content by weight of Al in the metal coating is from 1.5% to 3.9%.

13 . The sheet according to claim 10 , wherein the content by weight of Al in the metal coating is from 4.4% to 5.6%.

14 . The sheet according to claim 10 , wherein the content by weight of Mg in the metal coating is from 1.0% to 3.3%.

15 . The sheet according to claim 14 , wherein the content by weight of Mg in the metal coating is from 2.5% to 3.3%.

16 . The sheet according to claim 10 , wherein the content by weight of Mg in the metal coating is from 0.3% to 1.5%.

17 . The method according to claim 1 , wherein the remainder of the metal coating consists of Zn, inevitable impurities and at least one additional element selected from among Si, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Zr or Bi, the content by weight of each additional element in the metal coating being less than 0.3%.

18 . The method according to claim 1 , wherein the remainder of the metal coating consists of Zn and inevitable impurities.

19 . The sheet according to claim 10 , wherein the remainder of the metal coating consists of Zn, inevitable impurities and at least one additional element selected from among Si, Sb, Pb, Ti, Ca, Mn, Sn, La, Ce, Cr, Zr or Bi, the content by weight of each additional element in the metal coating being less than 0.3%.

20 . The sheet according to claim 10 , wherein the remainder of the metal coating consists of Zn and inevitable impurities.

Assignees

• Arcelormittal

Inventors

• Mataigne Jean-Michel

Classifications

• C23C2/06

  Zinc or cadmium or alloys based thereon · CPC title

• C22C18/04

  with aluminium as the next major constituent · CPC title

• 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

• C23C2/16 Primary

  using fluids under pressure, e.g. air knives · CPC title

• C23C2/26

  After-treatment (C23C2/14 takes precedence) · CPC title