Hot-dip al-plated steel sheet production method, and hot-dip al-plated steel sheet

Patent metadata

Field	Value
Publication number	US-2021002752-A1
Application number	US-201816982786-A
Country	US
Kind code	A1
Filing date	Mar 26, 2018
Priority date	Mar 26, 2018
Publication date	Jan 7, 2021
Grant date	—

Abstract

Provided is a method for producing a hot-dip Al-based metal-plated steel sheet including a plated layer having a surface on which fine spangle are stably formed. A method for producing a hot-dip Al-based metal-plated steel sheet, includes a composition adjusting step of adding a B-containing master alloy so as to adjust a composition of an Al-based hot-dip plating bath (3) containing aluminum as a main component, the composition being adjusted so that the Al-based hot-dip plating bath has a B concentration of not less than 0.005 mass % and a K concentration of more than 0 mass % and less than 0.0005 mass %, the K concentration being reduced in the Al-based hot-dip plating bath by supplying gas into the Al-based hot-dip plating bath so as to remove a suspended matter on a surface of the Al-based hot-dip plating bath.

First claim

1 . A method for producing a hot-dip Al-based metal-plated steel sheet, comprising:
a composition adjusting step of adding a B-containing master alloy so as to adjust a composition of an Al-based hot-dip plating bath containing aluminum as a main component, the composition being adjusted so that the Al-based hot-dip plating bath has a B concentration of not less than 0.005 mass % and a K concentration of more than 0 mass % and less than 0.0005 mass %; and a plating step of dipping a substrate steel sheet in the Al-based hot-dip plating bath, which has the composition thus adjusted, so as to cause the substrate steel sheet to pass through the Al-based hot-dip plating bath, in the composition adjusting step, the K concentration being reduced in the Al-based hot-dip plating bath by supplying gas into the Al-based hot-dip plating bath so as to remove a suspended matter on a surface of the Al-based hot-dip plating bath.

2 . The method as set forth in claim 1 , wherein in the composition adjusting step, the gas is supplied into the Al-based hot-dip plating bath by blowing the gas into the Al-based hot-dip plating bath.

3 . The method as set forth in claim 1 , wherein in the composition adjusting step, the gas is supplied into the Al-based hot-dip plating bath by using a stirring mechanism to stir the Al-based hot-dip plating bath on or near the surface of the Al-based hot-dip plating bath.

4 . The method as set forth in claim 3 , wherein the stirring mechanism is a stirring machine including a stirring blade.

5 . The method as set forth in claim 3 , wherein
the stirring mechanism is a drive roll including a rotation part that is rotatable on an axis by external power, and the gas is supplied into the Al-based hot-dip plating bath by dipping a part of the rotation part in the Al-based hot-dip plating bath so as to rotate the rotation part.

6 . A hot-dip Al-based metal-plated steel sheet produced by a method recited in claim 1 , comprising:
a substrate steel sheet; and a hot-dip Al-based metal-plated layer provided on a surface of the substrate steel sheet and having an average B concentration of not less than 0.005 mass % and an average K concentration of more than 0 mass % and less than 0.0005 mass %.

7 . The hot-dip Al-based metal-plated steel sheet as set forth in claim 6 , wherein the hot-dip Al-based metal-plated layer has a surface on which not less than 100 spangle crystal nuclei are present per square centimeter surface area of the hot-dip Al-based metal-plated layer.

Assignees

• Nippon Steel Corp

Inventors

• Furukawa Shinya
• Ishii Koutarou
• Hattori Yasunori

Classifications

• C23C2/12 Primary

  Aluminium or alloys based thereon · CPC title

• C23C2/40 Primary

  Plates; Strips · CPC title

• C22C1/03

  using master alloys · CPC title

• C22C21/02

  with silicon as the next major constituent · CPC title

• C22C21/04

  Modified aluminium-silicon alloys · CPC title