# US 8,147,983 B2 · Tin-plated steel sheet

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- Number: US 8,147,983 B2
- Document ID: US8147983B2
- Status: Granted
- Kind: B2
- Application number: 12/083,590
- Filed: 2006-10-20
- Published: 2009-06-18
- Granted: 2012-04-03
- Earliest claimed: 2005-10-20
- Assignees: Jfe Steel Corporation
- Inventors: Takeshi Suzuki; Noriko Makiishi; Hiroki Iwasa; Takumi Tanaka; Tomofumi Shigekuni
- Web page: https://patentgrep.com/patent/US8147983B2

## CPC

- C23C 22/08: Orthophosphates
- C23C 22/74: for obtaining burned-in conversion coatings
- C23C 28/321: {with at least one metal alloy layer}
- C23C 28/322: {only coatings of metal elements only}
- C23C 28/345: {with at least one oxide layer}
- C25D 3/30: of tin
- C25D 5/10: Electroplating with more than one layer of the same or of different metals (for bearings C25D7/10)
- C25D 5/48: After-treatment of electroplated surfaces
- C25D 9/08: by cathodic processes
- Y10T 428/12618: Plural oxides
- Y10T 428/12722: Next to Group VIII metal-base component
- Y10T 428/12972: Containing 0.01-1.7% carbon [i.e., steel]
- Y10T 428/12979: Containing more than 10% nonferrous elements [e.g., high alloy, stainless]
- Y10T 428/27: Web or sheet containing structurally defined element or component, the element or component having a specified weight per unit area [e.g., gms/sq cm, lbs/sq ft, etc.]
- C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04)
- C25D: PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A tin-plated steel sheet includes a plating layer containing tin on at least one surface of a steel sheet, and a chemical conversion coating containing P and tin on the plating layer is provided. In the steel sheet, a coated amount of the chemical conversion coating per surface is 1.0 to 50 mg/m2 in terms of P, an atomic ratio Sn/P obtained from the intensity of a P2p peak and that of a Sn3d peak is 1.0 to 1.5, the intensities being measured at the surface using an x-ray photoelectron spectroscopic method, and an atomic ratio O/P obtained from the intensity of the P2p peak and that of an O1s peak is 4.0 to 9.0. The phosphoric acid-based chemical conversion coating of the tin-plated steel sheet can suppress degradation in performance, which is caused by the growth of a tin oxide layer on the surface, instead of a conventional chromate coating.

## Claims

### Claim 1

A tin-plated steel sheet comprising:
a plating layer containing tin on at least one surface of a steel sheet; and
a chemical conversion coating consisting of P, O, H and tin on the plating layer,
wherein 1) a coated amount of the chemical conversion coating per surface is 1.0 to 50 mg/m2 in terms of P, an atomic ratio Sn/P obtained from the intensity of a P2p peak and that of a Sn3d peak of the chemical conversion coating is in the range of 1.0 to 1.3, the intensities being measured at the surface thereof using an x-ray photoelectron spectroscopic method, 2) an atomic ratio 0/P obtained from the intensity of the P2p peak and that of an O1s peak is in the range of 4.0 to 9.0, and optionally, 3) a ratio IOH/IPO between reflection-absorbance intensity of a PO bond (IPO) and reflection-absorbance intensity of an OH bond (IOH) of an infrared absorption spectrum of the chemical conversion coating is in the range of 0.18 to 0.30.

### Claim 2

A tin-plated steel sheet comprising:
a steel sheet;
a plating layer containing tin on at least one surface of the steel sheet; and
a chemical conversion coating consisting of P, O, H and tin on the plating layer in a coated amount of 1.0 to 50 mg/m2 in terms of P and having an atomic ratio Sn/P obtained from intensity of a P2p peak and that of a Sn3d peak of the chemical conversion coating in the range of 1.0 to 1.3,
wherein 1) the intensities are measured at a surface of the chemical conversion coating with an x-ray photoelectron spectroscopic method, 2) an atomic ratio 0/P obtained from the intensity of the P2p peak and that of an O1s peak is in the range of 4.0 to 9.0, and optionally 3) a ratio IOHH/IPO between reflection-absorbance intensity of a PO bond (IPO) and reflection-absorbance intensity of an OH bond (IOH) of an infrared absorption spectrum of the chemical conversion coating is in the range of 0.18 to 0.30.

### Claim 3

A tin-plated steel sheet comprising:
a plating layer containing tin on at least one surface of a steel sheet; and
a chemical conversion coating consisting of P, O, H and tin on the plating layer, wherein a coated amount of the chemical conversion coating per surface is 1.0 to 50 mg/m2 in terms of P, an atomic ratio Sn/P obtained from the intensity of a P2p peak and that of a Sn3d peak of the chemical conversion coating is in the range of 1.0 to 1.3, the intensities being measured at the surface thereof using an x-ray photoelectron spectroscopic method, and
an atomic ratio 0/P obtained from the intensity of the P2p peak and that of an O1s peak is in the range of 4.0 to 9.0.