Method for the manufacturing of liquid metal embrittlement resistant zinc coated steel sheet

Patent metadata

Field	Value
Publication number	US-11566310-B2
Application number	US-201816759253-A
Country	US
Kind code	B2
Filing date	Nov 15, 2018
Priority date	Nov 17, 2017
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

The present invention relates to a method for the manufacture of a coated steel sheet comprising the following successive steps: A. the coating of the steel sheet with a first coating consisting of nickel and having a thickness between 600 nm and 1400 nm, the steel sheet having the following composition in weight: 0.10<C<0.40%, 1.5<Mn<3.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0%, and on a purely optional basis, one or more elements such as Nb≤0.5%, B≤0.010%, Cr≤1.0%, Mo≤0.50%, Ni≤1.0%, Ti≤0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration, B. the recrystallization annealing at a temperature between 820 to 1200° C., C. the coating with a second coating based on zinc not comprising nickel.

First claim

What is claimed is:

1. A method for the manufacture of a coated steel sheet, the method comprising the following successive steps:
coating of a steel sheet with a first coating consisting of nickel and having a thickness between 600 nm and 950 nm, the steel sheet having the following composition in weight:
0.10<C<0.40%,
1.5<Mn<3.0%,
0.7<Si<3.0%,
0.05≤Al<1.0%,

0.75<(Si+Al)<3.0%,
and on a purely optional basis, one or more elements including:
Nb≤0.5%,

B≤0.010%,

Cr≤1.0%,

Mo≤0.50%,

Ni≤1.0%,

Ti≤0.5%,

a remainder of the composition making up of iron and inevitable impurities resulting from processing;
recrystallization annealing of the coated steel sheet at a temperature between 820 to 1200° C., performed in an atmosphere comprising from 1 to 10% of H 2 at a dew point between −30 and +30° C.; and
coating the steel sheet obtained in recrystallization annealing with a second coating based on zinc not comprising nickel.

2. The method as recited in claim 1 wherein the first coating has a thickness between 600 and 750 nm.

3. The method as recited in claim 1 wherein the recrystallization annealing is a continuous annealing.

4. The method as recited in claim 1 wherein in the recrystallization annealing is performed in an atmosphere comprising from 1 to 10% of H 2 at a dew point between −10 and +10° C.

5. The method as recited in claim 1 wherein the second coating includes above 50% of zinc.

6. The method as recited in claim 5 wherein the second coating includes above 75% of zinc.

7. The method as recited in claim 6 wherein the second coating includes above 90% of zinc.

8. The method as recited in claim 7 wherein the second coating consists of zinc.

9. The method as recited in claim 1 wherein the first coating has a thickness between 750 and 950 nm.

10. The method as recited in claim 1 wherein the first coating has a thickness between 650 and 900 nm.

Assignees

• Arcelormittal

Inventors

• Chakraborty Anirban
• Ghassemi-Armaki Hassan
• Bertho Pascal
• Allely Christian

Classifications

• C22C38/06

  containing aluminium · CPC title

• C21D9/46

  for sheet metals · CPC title

• B23K35/0255

  for use in welding (B23K35/0205 takes precedence) · CPC title

• C22C38/44

  with molybdenum or tungsten · CPC title

• C21D1/76 Primary

  Adjusting the composition of the atmosphere · CPC title