Hot-dip coated steel substrate

Patent metadata

Field	Value
Publication number	US-12227822-B2
Application number	US-202318142197-A
Country	US
Kind code	B2
Filing date	May 2, 2023
Priority date	Dec 19, 2017
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

A hot-dip coated steel substrate coated with a layer of Sn directly topped by a zinc or an aluminum based coating is provided, the steel substrate having the following chemical composition in weight percent:
0.10≤C≤0.4%, 1.2≤Mn≤6.0%, 0.3≤Si≤2.5%, Al<2.0%, and on a purely optional basis, one or more elements such as P<0.1%, Nb ≤0.5%, B≤ 0.005%, 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, the steel substrate further having between 0.0001 and 0.01% by weight of Sn in the region extending from the steel substrate surface up to 10 μm.

First claim

What is claimed is:

1. A hot-dip coated metallic steel substrate comprising:
a steel substrate surface coated with a layer of Sn directly topped by a zinc or aluminum based coating, the steel substrate having the following chemical composition in weight percent:
0.10≤C≤0.4%,
1.2≤Mn≤6.0%,
0.3≤Si≤2.5%,
Al≤2.0%,
and on a purely optional basis, at least one of the following elements:
P<0.1%,
nb≤0.5%,
B≤0.005%,
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, the steel substrate further comprising between 0.0001 and 0.005% by weight of Sn in a region extending from the steel substrate surface up to 10 μm.

2. The coated metallic substrate as recited in claim 1 wherein when the amount of Al in the steel substrate is 1.0% ≤Al≤2.0%, weight, and the amount of Mn in the steel substrate is 3.0 ≤Mn≤6.0%, by weight.

3. The coated metallic substrate as recited in claim 1 wherein the thin layer of Sn has a coating weight between 0.3 and 200 mg.m −2.

4. The coated metallic substrate as recited in claim 3 wherein the thin layer of Sn has a coating weight between 0.3 and 150 mg.m−2.

5. The coated metallic substrate as recited in claim 1 wherein the zinc or aluminum based coating is a zinc-based coating including from 0.01 to 8.0% by weight of Al, optionally from 0.2 to 8.0% by weight of Mg, a remainder being Zn.

6. The coated metallic substrate as recited in claim 5 wherein the zinc-based coating includes between 0.15 and 0.40% by weight of Al, the balance being Zn.

7. The coated metallic substrate as recited in claim 1 wherein the zinc or aluminum based coating is an aluminum-based coating.

8. The coated metallic substrate as recited in claim 1 wherein the steel substrate includes between 1.1 and 2.5% by weight of Si.

9. The coated metallic substrate as recited in claim 1 wherein the steel substrate includes between 0.5 and 1.1% by weight of Si.

10. The coated metallic substrate as recited in claim 1 wherein the steel substrate comprises 0.5% ≤Al≤2.0%, by weight.

11. The coated metallic substrate as recited in claim 10 wherein the steel substrate comprises 0.6% ≤Al≤2.0%, by weight of Al.

12. The coated metallic substrate as recited in claim 1 wherein a microstructure of the steel substrate includes ferrite, residual austenite and optionally martensite or bainite.

13. An automotive vehicle part comprising the coated metallic substrate as recited in claim 1 .

Assignees

• Arcelormittal

Inventors

• Bordignon Michel
• Staudte Jonas

Classifications

• C23C2/0224

  Two or more thermal pretreatments · CPC title

• C23C2/026

  Deposition of sublayers, e.g. adhesion layers or pre-applied alloying elements or corrosion protection · CPC title

• C25D3/30

  of tin · CPC title

• C23C2/06 Primary

  Zinc or cadmium or alloys based thereon · CPC title

• C23C2/02 Primary

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