Hot-dip Zn-based plated steel sheet

Patent metadata

Field	Value
Publication number	US-12247293-B2
Application number	US-202118041919-A
Country	US
Kind code	B2
Filing date	Aug 19, 2021
Priority date	Oct 16, 2020
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

This hot-dip Zn-based plated steel sheet includes a steel sheet and a plating layer formed on at least part of a surface of the steel sheet, in which the plating layer has a chemical composition that includes, by mass %, Al: 6.00% to 35.00%, Mg: 2.00% to 12.00%, Ca: 0.005% to 2.00%, Si: 0% to 2.00%, Fe: 0% to 2.00%, Sb: 0% to 0.50%, Sr: 0% to 0.50%, Pb: 0% to 0.50%, Sn; 0% to 1.00%, Cu: 0% to 1.00%, Ti: 0% to 1.00%, Ni: 0% to 1.00%, Mn: 0% to 1.00%, Cr: 0% to 1.00%, and a remainder: Zn and impurities; the plating layer has an area ratio of a MgZn 2 phase in a range of 15% to 60% in a cross section in a thickness direction, and the MgZn 2 phase includes a Ca-based intermetallic compound having a circle equivalent diameter of 0.10 μm or smaller.

First claim

What is claimed is:

1. A hot-dip Zn-based plated steel sheet comprising:
a steel sheet; and
a plating layer formed on at least part of a surface of the steel sheet,
wherein the plating layer has a chemical composition that includes, by mass %,
Al: 6.00% to 35.00%,
Mg: 2.00% to 12.00%,
Ca: 0.005% to 2.00%,
Si: 0% to 2.00%,
Fe: 0% to 2.00%,
Sb: 0% to 0.50%,
Sr: 0% to 0.50%,
Pb: 0% to 0.50%,
Sn: 0% to 1.00%,
Cu: 0% to 1.00%,
Ti: 0% to 1.00%,
Ni: 0% to 1.00%,
Mn: 0% to 1.00%,
Cr: 0% to 1.00%, and
a remainder: Zn and impurities,
the plating layer has an area ratio of a MgZn 2 phase in a range of 15% to 60% in a cross section in a thickness direction, and
the MgZn 2 phase includes a Ca-based intermetallic compound having a circle equivalent diameter of 0.10 μm or smaller.

2. The hot-dip Zn-based plated steel sheet according to claim 1 , wherein the chemical composition of the plating layer contains one or more selected from the group consisting of, by mass %,
Al: 11.00% to 30.00%,
Mg: 5.00% to 10.00%, and
Ca: 0.10% to 1.00%.

3. The hot-dip Zn-based plated steel sheet according to claim 1 , wherein a number density of the Ca-based intermetallic compound that is included in the MgZn 2 phase is 10 pieces/μm 2 or more.

4. The hot-dip Zn-based plated steel sheet according to claim 2 , wherein a number density of the Ca-based intermetallic compound that is included in the MgZn 2 phase is 10 pieces/μm 2 or more.

5. The hot-dip Zn-based plated steel sheet according to claim 1 , wherein an alloy layer that includes an Al—Fe-based intermetallic compound and has an average thickness in a range of 0.05 to 3.0 μm is provided between the plating layer and the steel sheet.

6. The hot-dip Zn-based plated steel sheet according to claim 2 , wherein an alloy layer that includes an Al—Fe-based intermetallic compound and has an average thickness in a range of 0.05 to 3.0 μm is provided between the plating layer and the steel sheet.

7. The hot-dip Zn-based plated steel sheet according to claim 3 , wherein an alloy layer that includes an Al—Fe-based intermetallic compound and has an average thickness in a range of 0.05 to 3.0 μm is provided between the plating layer and the steel sheet.

8. The hot-dip Zn-based plated steel sheet according to claim 4 , wherein an alloy layer that includes an Al—Fe-based intermetallic compound and has an average thickness in a range of 0.05 to 3.0 μm is provided between the plating layer and the steel sheet.

9. The hot-dip Zn-based plated steel sheet according to claim 1 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the plating layer.

10. The hot-dip Zn-based plated steel sheet according to claim 2 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the plating layer.

11. The hot-dip Zn-based plated steel sheet according to claim 3 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the plating layer.

12. The hot-dip Zn-based plated steel sheet according to claim 4 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the plating layer.

13. The hot-dip Zn-based plated steel sheet according to claim 5 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the alloy layer.

14. The hot-dip Zn-based plated steel sheet according to claim 6 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the alloy layer.

15. The hot-dip Zn-based plated steel sheet according to claim 7 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the alloy layer.

16. The hot-dip Zn-based plated steel sheet according to claim 8 , wherein the steel sheet has an internal oxidation layer in a surface layer area on a side of the alloy layer.

Assignees

• Nippon Steel Corp

Inventors

• Mitsunobu Takuya
• AKAHOSHI Makoto
• Takebayashi Hiroshi
• Takahashi Takehiro

Classifications

• C22F1/165

  of zinc or cadmium or alloys based thereon · CPC title

• C22F1/02

  in inert or controlled atmosphere or vacuum (adjusting the composition of the atmosphere C21D1/76) · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C38/02

  containing silicon · CPC title

• C22C18/04 Primary

  with aluminium as the next major constituent · CPC title