Method for the fabrication of a steel product comprising a step of characterization of a layer of oxides on a running steel substrate

Patent metadata

Field	Value
Publication number	US-10859370-B2
Application number	US-201615763889-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Sep 30, 2015
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A method for the fabrication of a steel product is provided. The method includes the steps of characterizing a layer of oxides present on a running steel substrate which includes providing a portion of the steel substrate comprising a layer of oxides and the portion defines an oxide surface, collecting light (Lr) from the oxide surface using a hyperspectral camera ( 20 ) in order to obtain intensity values (I λ,M ) respectively representative of an intensity of a part (Lr λ,M ) of the collected light, each part being respectively collected from one of a plurality of points (M) located on the oxide surface and respectively has a wavelength (λ) from a plurality of wavelengths, comparing the obtained intensity values with reference intensity values obtained for reference oxides, and calculating amounts of reference oxides in the layer. A device for characterizing a layer of oxides present on a steel substrate is also provided.

First claim

What is claimed is:

1. A method for the fabrication of a steel product comprising a step of characterization of a layer of oxides present on a running steel substrate, this step of characterization comprising the steps of:
providing a portion of a steel substrate comprising a layer of oxides, the portion defining an oxide surface;
collecting light (Lr) from the oxide surface using a hyperspectral camera in order to obtain intensity values (I λ,M ) respectively representative of an intensity of a part (Lr λ,M ) of the collected light (Lr), wherein each part (Lr λ,M ) is respectively collected from one of a plurality of points (M) located on the oxide surface and respectively has a wavelength (λ) from a plurality of wavelengths (λ 1 , λ 2 , . . . );
comparing the obtained intensity values (I λ,M ) with reference intensity values (R λ,M ) obtained for reference oxides; and
calculating amounts of reference oxides in the layer of oxides,
wherein the calculating of the amounts of reference oxides includes:
calculating reference absorbance values (OA λ,M ) using the reference intensity values (R λ,M ), and
calculating absorbance values (A λ,M ) using the intensity values (I λ,M ),
wherein the calculating of the reference absorbance values (OA λ,M ) and the absorbance values (A λ,M ) includes expressing the reference absorbance values (OA λ,M ) and the absorbance values (A λ,M ) respectively as

-

log
10

⁡

(

R

λ
,
M

-

D

λ
,
M

W

λ
,
M

-

D

λ
,
M

)

⁢

⁢
and

⁢

-

log
10

⁡

(

I

λ
,
M

-

D

λ
,
M

W

λ
,
M

-

D

λ
,
M

)

,

wherein D λ,M represents a noise of the hyperspectral camera, R λ,M represents the reference intensity values (R λ, M ), I λ,M represents the intensity values, and W λ,M represents a white value.

2. The method according to claim 1 , comprising a calibration step to determine the noise D λ,M of the hyperspectral camera and the white value W λ,M .

3. The method according to claim 1 , wherein the step of calculating amounts of reference oxides includes a baseline correction step.

4. A method for the fabrication of a steel product comprising a step of characterization of a layer of oxides present on a running steel substrate, this step of characterization comprising the steps of:
providing a portion of a steel substrate comprising a layer of oxides, the portion defining an oxide surface;
collecting light (Lr) from the oxide surface using a hyperspectral camera in order to obtain intensity values (I λ,M ) respectively representative of an intensity of a part (Lr λ,M ) of the collected light (Lr), wherein each part (Lr λ,M ) is respectively collected from one of a plurality of points (M) located on the oxide surface and respectively has a wavelength (λ) from a plurality of wavelengths (λ 1 , λ 2 , . . . );
comparing the obtained intensity values (I λ,M ) with reference intensity values (R λ,M ) obtained for reference oxides; and
calculating amounts of reference oxides in the layer of oxides,
the method further comprising:
calculating a parameter representative of a surface of an area located under a curve, the curve being obtained by plotting the absorbance values (A λ,M ) versus the plurality of wavelengths (λ 1 , λ 2 , . . . ); and
calculating a thickness of the layer of oxides, the thickness being obtained as a function of at least the parameter.

5. The method according to claim 4 , wherein the function is linear.

6. The method according to claim 4 , further comprising a step of:
determining the function for at least one of the reference oxides by using a plurality of reference oxide samples, wherein the plurality of reference oxide samples respectively comprises a substrate made of the steel and a layer of the at least one reference oxide deposited on the substrate, wherein the layers respectively have a plurality of thicknesses.

7. The method according to claim 1 , wherein the incident light defines an angle (α) with a direction that is perpendicular to the oxide surface, the angle (α) being from 40° to 80°.

8. The method according to claim 1 , wherein the collected light (Lr) and the reference collected light (Lrr) are obtained by spontaneous emission of light respectively by the oxide surface and by the surface made of the steel.

9. The method according to claim 1 , wherein the plurality of wavelengths (λ 1 , λ 2 , . . . ) comprises wavelengths ranging from 8 μm to 12 μm.

10. The method according to claim 1 , wherein all the wavelengths of the plurality of wavelengths (λ 1 ,

Assignees

• Arcelormittal

Inventors

• Fricout Gabriel
• Glijer David

Classifications

• G01B11/0625 Primary

  with measurement of absorption or reflection · CPC title

• C23C2/0038

  characterised by the pre-treatment chambers located immediately upstream of the bath or occurring locally before the dipping process · CPC title

• G01N2021/8411

  Application to online plant, process monitoring · CPC title

• G01N21/8422

  Investigating thin films, e.g. matrix isolation method · CPC title

• G01N2021/8427

  Coatings · CPC title