Steel sheet coated with a metallic coating based on aluminum and comprising titanium

Patent metadata

Field	Value
Publication number	US-10947608-B2
Application number	US-201615765831-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Oct 5, 2015
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A steel sheet coated with a metallic coating is provided. The coating includes from 1.0 to 22.0% by weight of zinc, from 0.1 to 1.0% by weight of titanium, from 1.6 to 15.0% by weight of silicon, below 0.5% by weight of magnesium, below 0.05% by weight of La or Ce or both, below 0.2% by weight of Sn and optionally, less than 0.3% by weight of additional elements chosen from Sb, Pb, Ca, Mn, Cr, Ni, Zr, In, Hf or Bi. A balance of the coating includes aluminum and optionally unavoidable impurities and residual elements. A microstructure of the coating does not include Al—Zn binary phases. A coated part is also provided.

First claim

The invention claimed is:

1. A steel sheet coated with a metallic coating, the metallic coating comprising:
5.0 to 22.0% by weight of zinc;
0.1 to 1.0% by weight of titanium;
1.6 to 15.0% by weight of silicon;
less than 0.5% by weight of magnesium;
less than 0.05% by weight of La;
less than 0.05% by weight of Ce;
less than 0.2% by weight of Sn; and
a balance of the composition being aluminum and unavoidable impurities and residual elements; and
a microstructure of the coating does not comprise Al—Zn binary phases.

2. The steel sheet according to claim 1 , wherein the coating optionally includes additional elements chosen from Sb, Pb, Ca, Mn, Cr, Ni, Zr, In, Hf or Bi, a content by weight of each additional element being less than 0.3% by weight.

3. The steel sheet according to claim 1 , wherein the coating comprises from 5.0 to 20.0% by weight of zinc.

4. The steel sheet according to claim 3 , wherein the coating comprises from 10.0 to 20.0% by weight of zinc.

5. The steel sheet according to claim 1 , wherein the coating comprises from 0.15 to 1.0% of weight of titanium.

6. The steel sheet according to claim 5 , wherein the coating comprises from 0.15 to 0.50% of weight of titanium.

7. The steel sheet according to claim 6 , wherein the coating comprises from 0.15 to 0.30% of weight of titanium.

8. The steel sheet according to claim 7 , wherein the coating comprises from 0.20 to 0.30% of weight of titanium.

9. The steel sheet according to claim 8 , wherein the coating comprises from 0.21 to 0.30% of weight of titanium.

10. The steel sheet according to claim 1 , wherein the coating comprises from 2.05 to 11.0% by weight of silicon.

11. The steel sheet according to claim 10 , wherein the coating comprises from 5.0 to 11.0% by weight of silicon.

12. The steel sheet according to claim 11 , wherein the coating comprises from 7.0 to 11.0% by weight of silicon.

13. The steel sheet according to claim 12 , wherein the coating comprises below 0.2% by weight of magnesium.

14. The steel sheet according to claim 1 , wherein the microstructure of the coating comprises Zn solid solution in Al phase and Si phases.

15. The steel sheet according to claim 1 , wherein a thickness of the coating is between 5 and 50 μm.

16. A part comprising:
a steel sheet coated with a metallic coating, the metallic coating comprising:
5.0 to 22.0% by weight of zinc;
0.1 to 1.0% by weight of titanium;
1.6 to 15.0% by weight of silicon;
less than 0.5% by weight of magnesium;
less than 0.05% by weight of La;
less than 0.05% by weight of Ce;
less than 0.2% by weight of Sn; and
a balance of the composition being aluminum and unavoidable impurities and residual elements; and
a microstructure of the coating does not comprise Al—Zn binary phases;
the steel sheet subject to hot-forming or cold-forming or both to form the part.

17. An automotive vehicle comprising:
the part according to claim 16 .

18. The steel sheet according to claim 4 , wherein the coating comprises from 10.0 to 15.0% by weight of zinc.

19. The steel sheet according to claim 1 , wherein the metallic coating comprises:
10.0 to 20.0% by weight of zinc;
0.10 to 0.50% by weight of titanium;
7.0 to 11.0% by weight of silicon; and
at least 70.5% by weight of aluminum.

20. The steel sheet according to claim 1 , wherein the steel sheet has a coupling potential of less than −0.78V/SCE or less.

21. The steel sheet according to claim 1 , wherein the steel sheet has a coupling potential of from −0.78V/SCE to −1.4V/SCE.

22. The steel sheet according to claim 1 , wherein the metallic coating does not include Mg or Ca.

23. The steel sheet according to claim 1 , wherein the metallic coating consists of:
5.0 to 22.0% by weight of zinc;
0.1 to 1.0% by weight of titanium;
1.6 to 15.0% by weight of silicon;
less than 0.05% by weight of La;
less than 0.05% by weight of Ce;
less than 0.2% by weight of Sn; and
less than 0.3% by weight of each of Sb, Pb, Mn, Cr, Ni, Zr, In, Hf or Bi;
the balance of the composition being aluminum and unavoidable impurities and residual elements.

24. The steel sheet according to claim 23 , wherein the metallic coating consists of:
5.0 to 22.0% by weight of zinc;
0.1 to 1.0% by weight of titanium;
1.6 to 15.0% by weight of silicon; and
the balance of the composition being aluminum and unavoidable impurities and residual elements.

25. The steel sheet according to claim 1 , wherein the microstructure is martensitic, martensito-bainitic or includes at least 75% equiaxed ferrite, from 5 to 20% martensite and 10% or less bainite.

Assignees

• Arcelormittal

Inventors

• Allely Christian
• Machado Amorim Tiago
• Corlu Beril
• De Strycker Joost

Classifications

• C23C2/12 Primary

  Aluminium or alloys based thereon · CPC title

• C21D2211/008

  Martensite · CPC title

• C23C2/40

  Plates; Strips · CPC title

• C21D2211/002

  Bainite · CPC title

• Y10T428/12757

  Fe · CPC title