Chemical treatment steel sheet, and method for producing chemical treatment steel sheet

Patent metadata

Field	Value
Publication number	US-2017253984-A1
Application number	US-201515320404-A
Country	US
Kind code	A1
Filing date	Oct 8, 2015
Priority date	Oct 9, 2014
Publication date	Sep 7, 2017
Grant date	—

Abstract

Provided is a chemical treatment steel sheet including a steel sheet; a composite coated layer which is formed on at least one surface of the steel sheet, and contains 2 to 200 mg/m 2 of Ni in terms of an amount of metal Ni and 0.1 to 10 g/m 2 of Sn in terms of an amount of metal Sn, and in which an island-shaped Sn coated layer is formed on an Fe—Ni—Sn alloy layer; and a chemical treatment layer that is formed on the composite coated layer, and contains a 0.01 to 0.1 mg/m 2 of Zr compounds in terms of an amount of metal Zr and 0.01 to 5 mg/m 2 of phosphate compounds in terms of an amount of P.

First claim

1 . A chemical treatment steel sheet comprising:
a steel sheet; a composite coated layer which is formed on at least one surface of the steel sheet, and contains 2 to 200 mg/m 2 of Ni in terms of an amount of metal Ni and 0.1 to 10 g/m 2 of Sn in terms of an amount of metal Sn, and in which an island-shaped Sn coated layer is formed on a Fe—Ni—Sn alloy layer; and a chemical treatment layer that is formed on the composite coated layer, and contains 0.01 to 0.1 mg/m 2 of Zr compounds in terms of an amount of metal Zr and 0.01 to 5 mg/m 2 of phosphate compounds in terms of an amount of P.

2 . The chemical treatment steel sheet according to claim 1 ,
wherein the chemical treatment layer contains 0.08 mg/m 2 or less of the Zr compounds in terms of the amount of metal Zr.

3 . The chemical treatment steel sheet according to claim 2 ,
wherein the chemical treatment layer contains 0.06 mg/m 2 or less of the Zr compounds in terms of the amount of metal Zr.

4 . The chemical treatment steel sheet according to claim 1 ,
wherein the chemical treatment layer contains 0.02 mg/m 2 or greater of the Zr compounds in terms of the amount of metal Zr.

5 . The chemical treatment steel sheet according to claim 1 ,
wherein the chemical treatment layer contains 4 mg/m 2 or less of the phosphate compounds in terms of the amount of P.

6 . The chemical treatment steel sheet according to claim 1 ,
wherein the chemical treatment layer contains less than 1 mg/m 2 of the phosphate compounds in terms of the amount of P.

7 . The chemical treatment steel sheet according to claim 1 ,
wherein the chemical treatment layer contains 0.03 mg/m 2 or greater of the phosphate compounds in terms of the amount of P.

8 . The chemical treatment steel sheet according to claim 1 ,
wherein when a variation amount in a yellowness index before and after storage for 4 weeks in an environment of a temperature of 40° C. and a humidity of 80% at one measurement point on an outermost surface of the chemical treatment layer is defined as ΔYI, an average value of the ΔYI obtained at the measurement points included in a unit area of the outermost surface is less than 1.7.

9 . The chemical treatment steel sheet according to claim 1 ,
wherein the composite coated layer contains 2 to 180 mg/m 2 of Ni in terms of the amount of metal Ni, and 0.2 to 8 mg/m 2 of Sn in terms of the amount of metal Sn.

10 . The chemical treatment steel sheet according to claim 1 ,
wherein a surface of the chemical treatment layer is not coated with a film or a coating.

11 . A method for producing a chemical treatment steel sheet, comprising:
a plating process that forms an Ni coated layer that contains 2 to 200 mg/m 2 of Ni in terms of an amount of metal Ni and an Sn coated layer that contains 0.1 to 10 g/m 2 of Sn in terms of an amount of metal Sn on a surface of a steel sheet; a reflow process that forms an Fe—Ni—Sn alloy layer on the steel sheet and an island-shaped Sn coated layer on the Fe—Ni—Sn alloy layer by performing a reflow treatment with respect to the steel sheet in which the Ni coated layer and the Sn coated layer are formed; and a chemical treatment process that forms a chemical treatment layer on the island-shaped Sn coated layer by performing an electrolytic treatment in a chemical treatment liquid, which contains equal to or greater than 10 ppm and less than 500 ppm of Zr ions, 10 to 20000 ppm of F ions, 10 to 3000 ppm of phosphate ions, and 100 to 30000 ppm in a total amount of nitrate ions and sulfate ions and of which a temperature is set to equal to or higher than 5° C. and lower than 90° C., under conditions of a current density of 0.5 to 20 A/dm 2 and an electrolytic treatment time of 0.05 to 10 seconds, or by performing an immersion treatment in the chemical treatment liquid for an immersion time of 0.2 to 100 seconds.

12 . The method for producing a chemical treatment steel sheet according to claim 11 ,
wherein the chemical treatment liquid contains 100 ppm to less than 500 ppm of Zr ions, 100 to 17000 ppm of F ions, 20 to 2000 ppm of phosphate ions, and 1000 to 20000 ppm in a total amount of nitrate ions and sulfate ions.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Tani Yoshiaki
• Hirano Shigeru
• Tachiki Akira
• Yanagihara Morio
• Kawabata Makoto
• Yokoya Hirokazu

Classifications

• C25D5/48

  After-treatment of electroplated surfaces · CPC title

• C25D5/50

  by heat-treatment · CPC title

• C23C22/361

  containing titanium, zirconium or hafnium compounds · CPC title

• Y10T428/12611

  Oxide-containing component · CPC title

• Y10T428/12708

  Sn-base component · CPC title