Heat-resistant and anticorrosive lamellar metal-plated steel material with uniform processability and anticorrosiveness

• US 6,071,631 A
• Filed: 11/26/1997
• Issued: 06/06/2000
• Est. Priority Date: 11/14/1994
• Status: Expired due to Term

• Current Assignee: Usui Kokusai Sangyo Kaisha Limited
• Original Assignee: Usui Kokusai Sangyo Kaisha Limited
• Inventors: Takahata, Seiya
• Primary Examiner(s): Zimmerman, John J.
• Application Number:
  US08/979,483
• Time in Patent Office: 923 Days
• Field of Search: 428/658, 428/659, 428/615, 428/632, 428/678, 428/679, 428/935, 205/176, 205/177, 205/246
• US Class Current: 428/658
• CPC Class Codes: C25D 5/14 two or more layers being of nickel or chromium, e.g. duplex or triplex layers
• CPC Class Codes: Y10S 428/935 Electroplating
• CPC Class Codes: Y10T 428/12611 Oxide-containing component
• CPC Class Codes: Y10T 428/12792 Zn-base component
• CPC Class Codes: Y10T 428/12799 Next to Fe-base component [e.g., galvanized]
• CPC Class Codes: Y10T 428/12937 Co- or Ni-base component next to Fe-base component

Abstract

The present invention has for its object to obtain a heat-resistant and anticorrosive multilayer metal-plated steel object which excels in the uniformity of high-efficiency processability and anticorrosiveness. The steel object provided by the present invention to achieve such object comprises a steel substrate, a Ni-layer plated over the surface of the steel substrate to a thickness of 0.2-10 μm, a first Zn/Ni alloy layer plated over the Ni-layer to a thickness of 1-15 μm from an acid bath, such as a chloride bath or sulfuric acid bath, with the Ni-content of the first layer being in the range of 2-20% by weight and a second Zn/Ni alloy layer plated over the first Zn/Ni alloy layer to a thickness of 1-10 μm from an alkaline bath, with the Ni-content thereof being in the range of 2-20% by weight.

Claims

1. A steel material having, on the outer surface thereof,

a Ni-layer having a thickness of 0.2 to 10 μ

m;

a first Zn/Ni alloy layer having a thickness of 1 to 15 μ

m disposed over the Ni-layer, wherein the first Zn/Ni alloy layer has been plated using an acid bath; and

a second Zn/Ni alloy layer having a thickness of 1 to 10 μ

m disposed over the first Zn/Ni alloy layer, wherein the second Zn/Ni alloy layer has been plated using an alkaline bath.

2. The steel material according to claim 1, wherein the Ni-layer is formed by electro-plating using a Watt bath.

3. The steel material according to claim 1, wherein the first Zn/Ni alloy layer is formed by electro-plating using a chloride bath or a sulfuric acid bath.

4. The steel material according to claim 1, wherein the second Zn/Ni alloy layer is formed by electro-plating.

5. A steel material having, on the outer surface thereof,

a Ni-layer having a thickness of 0.2 to 10 μ

m;

a first Zn/Ni alloy layer having a thickness of 1 to 15 μ

m disposed over the Ni-layer, wherein the first Zn/Ni alloy layer has been plated using an acid bath;

a second Zn/Ni alloy layer having a thickness of 1 to 10 μ

m disposed over the first Zn/Ni alloy layer, wherein the second Zn/Ni alloy layer has been plated using an alkaline bath; and

a chromate film plated over the second alloy layer.

6. The steel material according to claim 5, wherein the Ni-layer is formed by electro-plating using a Watt bath.

7. The steel material according to claim 5, wherein the first Zn/Ni alloy layer is formed by electro-plating using a chloride bath or a sulfuric acid bath.

8. The steel material according to claim 5, wherein the second Zn/Ni alloy layer is formed by electro-plating.

9. The steel material according to claim 5, wherein the chromate film is deposited from a processing liquid consisting essentially of chromic acid or dichromic acid and sulfuric acid or hydrochloric acid.