Method of producing surface-treated steel sheet

Patent metadata

Field	Value
Publication number	US-2016002810-A1
Application number	US-201414768687-A
Country	US
Kind code	A1
Filing date	Jan 30, 2014
Priority date	Feb 27, 2013
Publication date	Jan 7, 2016
Grant date	—

Abstract

A method of producing a surface-treated steel sheet is provided. The surface-treated steel sheet includes a layer that contains a metal oxide. The method is characterized by including: dipping a steel sheet for 0.1 to 10 seconds in a treatment liquid that contains at least fluoride ions and has a pH of 2 to 5; and electrically treating by flowing a direct current between the steel sheet and an electrode in a treatment liquid to form a layer that contains a metal oxide on a surface of the steel sheet. According to the present invention, there can be provided a method of producing a surface-treated steel sheet which can enhance the interfacial adhesion with an organic resin layer when the organic resin layer is formed on the metal oxide layer.

First claim

1 . A method of producing a surface-treated steel sheet comprising:
dipping a steel sheet for 0.1 to 10 seconds into a treatment liquid that contains at least fluoride ions and has a pH of 2 to 5; and electrically treating by flowing a direct current between the steel sheet and an electrode in a treatment liquid to form a layer that contains a metal oxide on a surface of the steel sheet.

2 . The method of producing a surface-treated steel sheet according to claim 1 , wherein
dipping includes continuously feeding the steel sheet into a dip treatment bath that is filled with a dip treatment liquid thereby to dip the steel sheet into the dip treatment liquid, and electrically treating includes, after dipping the steel sheet into the dip treatment liquid, continuously feeding the steel sheet into an electrolytic treatment bath that is filled with a metal ion-containing electrolytic treatment liquid and at least one electrode and electrically treating by flowing the direct current between the steel sheet and the electrode in the electrolytic treatment liquid.

3 . The method of producing a surface-treated steel sheet according to claim 2 , wherein the dip treatment liquid contains a part of constituents of those contained in the electrolytic treatment liquid.

4 . The method of producing a surface-treated steel sheet according to claim 2 , wherein aqueous solutions that contain the same constituents are used as the dip treatment liquid and the electrolytic treatment liquid.

5 . The method of producing a surface-treated steel sheet according to claim 2 , wherein aqueous solutions that contain the same constituents at the same content ratio are used as the dip treatment liquid and the electrolytic treatment liquid.

6 . The method of producing a surface-treated steel sheet according claim 2 , wherein the electrolytic treatment liquid contains ions of at least one kind of metal selected from Zr, Al and Ti.

7 . The method of producing a surface-treated steel sheet according to claim 1 , wherein the steel sheet is a cold-rolled steel sheet from which iron is exposed at least one surface thereof.

8 . The method of producing a surface-treated steel sheet according to claim 1 , wherein a molar concentration of metal in the layer formed on the surface of the steel sheet is 0.3 mmol/m 2 or more.

9 . The method of producing a surface-treated steel sheet according to claim 1 , wherein the layer that contains the metal oxide is formed on the surface of the steel sheet without pickling the steel sheet with acid.

Assignees

• Toyo Kohan Co Ltd

Inventors

• Yoshimura Kunihiro
• Taguchi Naomi
• Fukutomi Satoko

Classifications

• C25D3/54

  of metals not provided for in groups C25D3/04 - C25D3/50 · CPC title

• C25D3/44

  Aluminium · CPC title

• C25D7/00

  Electroplating characterised by the article coated · CPC title

• C25D9/10 Primary

  on iron or steel · CPC title

• C23G1/086

  solutions containing HF · CPC title