Method for calculating film thickness of grain boundary oxide layer, method for determining plating properties, method for manufacturing plated steel sheet, and film thickness calculation device

Patent metadata

Field	Value
Publication number	US-2025164422-A1
Application number	US-202218707821-A
Country	US
Kind code	A1
Filing date	Oct 26, 2022
Priority date	Nov 18, 2021
Publication date	May 22, 2025
Grant date	—

Abstract

A method for calculating a film thickness of a grain boundary oxide layer remaining on a steel sheet after a pickling treatment, may include: an intensity-measuring in which a fluorescent X-ray intensity of an element being contained in the steel sheet and constituting an oxide in the grain boundary oxide layer is measured; and a film thickness-calculating in which a film thickness of the grain boundary oxide layer is calculated based on: a correlation between a pre-extracted fluorescent X-ray intensity and the film thickness of the grain boundary oxide layer; and the fluorescent X-ray intensity measured in the intensity-measuring.

First claim

1 . A method for calculating a film thickness of a grain boundary oxide layer remaining on a steel sheet after a pickling treatment, the method comprising:
intensity-measuring a fluorescent X-ray intensity of an element comprised in the steel sheet and constituting an oxide in the grain boundary oxide layer; and film thickness-calculating, using the fluorescent X-ray intensity measured in the intensity-measuring, a film thickness of the grain boundary oxide layer based on a correlation between a pre-extracted fluorescent X-ray intensity and the film thickness of the grain boundary oxide layer.

2 . The method of claim 1 , wherein a plurality of correlations are pre-extracted in accordance with manufacturing conditions of the steel sheet, and
wherein in the film thickness-calculating, one correlation is selected from the plurality of correlations in accordance with the manufacturing conditions of the steel sheet.

3 . The method of claim 1 , further comprising:
distance-measuring a measurement distance, the measurement distance being a distance between the steel sheet and a measurement position of the fluorescent X-ray intensity measured in the intensity-measuring; and intensity-correcting the fluorescent X-ray intensity measured in the intensity-measuring is based on the measurement distance, wherein, in the film thickness-calculating, the fluorescent X-ray intensity corrected in the intensity-correcting is used instead of the fluorescent X-ray intensity measured in the intensity-measuring.

4 . The method of claim 1 , wherein an acid used in the pickling treatment is hydrochloric acid, and
wherein the element in the intensity-measuring is Mn.

5 . A method for determining plating properties of a steel sheet from a grain boundary oxide layer remaining on the steel sheet after a pickling treatment, the method comprising:
calculating a film thickness of the grain boundary oxide layer by the method of claim 1 ; and determining plating properties of the steel sheet by using, as a determination indicator, the film thickness of the grain boundary oxide layer calculated in the calculating.

6 . A method for determining plating properties of a steel sheet from a grain boundary oxide layer remaining on the steel sheet after a pickling treatment, the method comprising:
intensity-measuring a fluorescent X-ray intensity of an element being comprised in the steel sheet and constituting an oxide in the grain boundary oxide layer; and determining plating properties of the steel sheet directly based on the fluorescent X-ray intensity measured in the intensity-measuring.

7 . A method for manufacturing a plated steel sheet, the method comprising:
hot-rolling a steel sheet serving as a base material; pickling an oxide scale on a surface of the steel sheet after the hot-rolling is removed, by an acid; and plating property-determining plating properties of the steel sheet from a grain boundary oxide layer remaining on the steel sheet after the pickling, comprising using the method of claim 5 .

8 . A film thickness calculation device configured for measuring a film thickness of a grain boundary oxide layer remaining on a steel sheet after a pickling treatment, the film thickness calculation device comprising:
an intensity measurer configured for measuring a fluorescent X-ray intensity of an element being comprised in the steel sheet and constituting an oxide in the grain boundary oxide layer; a distance measurer configured for measuring a measurement distance being a distance between the steel sheet and a measurement position of the fluorescent X-ray intensity of the intensity measurement portion; an intensity corrector configured for correcting, based on the measurement distance, the fluorescent X-ray intensity measured by the intensity measurement portion; and a film thickness calculator configured for calculating a film thickness of the grain boundary oxide layer based on: a correlation between a pre-extracted fluorescent X-ray intensity and the film thickness of the grain boundary oxide layer; and the fluorescent X-ray intensity corrected by the intensity correction portion.

9 . The device of claim 8 , further comprising:
a storage configured for storing a plurality of correlations extracted in accordance with manufacturing conditions of the steel sheet, wherein the film thickness calculation portion comprises a function of selecting one correlation from the plurality of correlations in accordance with the manufacturing conditions of the steel sheet.

10 . A method for manufacturing a plated steel sheet, the method comprising:
hot-rolling a steel sheet serving as a base material; pickling an oxide scale on a surface of the steel sheet, after the hot-rolling is removed, by an acid; and plating property-determining plating properties of the steel sheet from a grain boundary oxide layer remaining on the steel sheet after the pickling, comprising using the method of claim 6 .

Assignees

• Kobe Steel Ltd

Inventors

• Sasaki Koji
• Kobayashi Masanori
• Fukushima Koki
• Hayashi Kazushi
• Inui Masahiro

Classifications

• G01N2223/624

  steel, castings · CPC title

• G01N2223/61

  thin films, coatings · CPC title

• G01N23/2202

  Preparing specimens therefor · CPC title

• G01B15/02 Primary

  for measuring thickness · CPC title

• C23G1/08

  Iron or steel · CPC title