HOT-DIP Al-Zn ALLOY COATED STEEL SHEET AND METHOD FOR PRODUCING SAME

• US 20150361538A1
• Filed: 02/17/2014
• Published: 12/17/2015
• Est. Priority Date: 03/28/2013
• Status: Active Grant

• Current Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: JFE Steel Corporation (JFE Holdings Incorporated)
• Inventors: YOSHIDA, Masahiro, MATSUZAKI, Akira, ANDO, Satoru
• Granted Patent: US 9,758,853 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B32B 15/012 one layer being formed of an iron alloy or steel, another layer being formed of aluminium or an aluminium alloy
• CPC Class Codes: B32B 15/013 one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium
• CPC Class Codes: C22C 18/04 with aluminium as the next major constituent
• CPC Class Codes: C22C 21/00 Alloys based on aluminium
• CPC Class Codes: C22C 21/10 with zinc as the next major constituent
• CPC Class Codes: C23C 2/00 Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
• CPC Class Codes: C23C 2/04 characterised by the coating material
• CPC Class Codes: C23C 2/06 Zinc or cadmium or alloys based thereon
• CPC Class Codes: C23C 2/12 Aluminium or alloys based thereon
• CPC Class Codes: C23C 2/26 After-treatment C23C2/14 takes precedence
• CPC Class Codes: C23C 2/28 Thermal after-treatment, e.g. treatment in oil bath
• CPC Class Codes: C23C 2/40 Plates; Strips
• CPC Class Codes: C23C 2/405 Plates of specific length
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: C23C 30/005 on hard metal substrates
• CPC Class Codes: Y10T 428/12757 Fe
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12972 Containing 0.01-1.7% carbon [i.e., steel]
• CPC Class Codes: Y10T 428/12979 Containing more than 10% nonferrous elements [e.g., high alloy, stainless]
• CPC Class Codes: Y10T 428/12993 Surface feature [e.g., rough, mirror]

Abstract

Disclosed is a hot-dip Al—Zn alloy coated steel sheet having excellent anti-corrosion property after coating, and a method for producing the same. In the disclosure, the hot-dip Al—Zn alloy coated steel sheet has a hot-dip coating layer containing by mass %, Al: 25% to 90%, and at least one of Sn: 0.01% to 2.0%, In: 0.01% to 10%, and Bi: 0.01% to 2.0%.

Claims

1. A hot-dip Al—

Zn alloy coated steel sheet having a hot-dip coating layer, wherein the hot-dip coating layer contains by mass %, Al;

25% to 90%, and at least one element selected from a group consisting of Sn;

0.01% to 2.0%, In;

0.01% to 10%, and Bi;

0.01% to 2.0%.

2. The hot-dip Al—

Zn alloy coated steel sheet according to claim 1, wherein the hot-dip coating layer further contains by mass %, Zn;

10% or more.

3. The hot-dip Al—

Zn alloy coated steel sheet according to claim 1, wherein the hot-dip coating layer further contains by mass %, Si;

0.1% to 10%.

4. The hot-dip Al—

Zn alloy coated steel sheet according to claim 1, wherein the Al content of the hot-dip coating layer is 45 mass % to 70 mass %.

5. The hot-dip Al—

Zn alloy coated steel sheet according to claim 1, wherein the hot-dip coating layer contains at least one element selected from a group consisting of Sn;

0.01 mass % to 1.0 mass %, In;

0.01 mass % to 1.0 mass %, and Bi;

0.01 mass % to 1.0 mass %.

6. The hot-dip Al—

Zn alloy coated steel sheet according to claim 1, wherein the mean Vickers hardness of the hot-dip coating layer is 50 Hv to 100 Hv.

7. A method for producing a hot-dip Al—

Zn alloy coated steel sheet in a continuous galvanizing line, the method comprising;

immersing a base steel sheet in a molten bath to apply hot-dip coating thereon, the molten bath containing by mass %, Al;

25% to 90%;

at least one element selected from a group consisting of Sn;

0.01% to 2.0%, In;

0.01% to 10%, and Bi;

0.01% to 2.0%; and

the balance including Zn and incidental impurities.

8. The method for producing a hot-dip Al—

Zn alloy coated steel sheet according to claim 7, wherein the molten bath contains by mass %, Zn;

10% or more.

9. The method for producing a hot-dip Al—

Zn alloy coated steel sheet according to claim 7, wherein the molten bath contains by mass %, Si;

0.1% to 10%.

10. The method for producing a hot-dip Al—

Zn alloy coated steel sheet according to claim 7, wherein the molten bath contains by mass %, at least one element selected from a group consisting of Sn;

0.01% to 1.0%, In;

0.01% to 1.0%, and Bi;

0.01% to 1.0%.

11. The method for producing a hot-dip Al—

Zn alloy coated steel sheet according to claim 7, further comprising holding the hot-dip coated steel sheet at a temperature of 250°

C. to 375°

C. for 5 seconds to 60 seconds.

12. The method for producing a hot-dip Al—

Zn alloy coated steel sheet according to claim 11, wherein the hot-dip coated steel sheet is held at a temperature of 300°

C. to 375°

C. for 5 seconds to 60 seconds.