US 6,480,274 B1 · Method of analyzing oxygen and oxide in metallic material

Abstract

This invention provides a quantitative determination method capable of quickly determining a mean composition of oxide type inclusions and oxygen concentration of a metallic material such as a steel by using an optical emission spectrometer alone. This method comprises the steps of (1) conducting a plurality of times a discharge operation between the metallic material and an opposing electrode in an inert gas atmosphere to obtain an emission spectrochemical spectrum, (2) selecting a discharge in which at least either the oxygen A spectrum or the oxide-forming element spectrum exceed a predetermined intensity for each discharge operation, and (3) subtracting a background from the intensity of the oxygen spectrum and/or the intensity of the oxide-forming elements in the selected discharge, accumulating the balances to obtain a cumulative spectral intensity, and executing quantitative determination by a calibration curve method.

Claims10

Dependent claims

A method of quantitatively determining mean oxide-forming element concentrations originating from oxides in a metallic material, the method comprising the steps of:

(1) conducting a discharge operation a plurality of times between said metallic material and an opposing electrode in an inert gas atmosphere to obtain emission spectra;
(2) selecting from said spectra the discharge by which an oxide-forming element spectrum and an oxygen spectrum exceed predetermined respective intensities;
(3) subtracting said predetermined intensity of said oxide-forming elements as a background from the intensity of said oxide-forming element spectrum in said selected discharge, and accumulating spectra balances to obtain a cumulative spectral intensity;
and
(4) executing quantitative determination using a calibration curve, of the oxide-forming element concentration originating from oxides and said cumulative spectra intensity, prepared separately.

2 more elements

A method of quantitatively determining a mean oxygen concentration in a metallic material comprising the steps of:

(1) conducting a discharge operation a plurality of times between said metallic material and an opposing electrode in an inert gas atmosphere to obtain emission spectra;
(2) selecting the discharge in which an oxide-forming element spectrum exceeds a predetermined intensity;
(3) selecting oxygen spectra obtained by said discharge;
(4) determining a background of the oxygen spectra from a frequency distribution of the intensity of the oxygen spectra and the number of discharges in the oxygen spectra other than the oxygen spectra selected by the step (3);
(5) selecting again the oxygen spectra having intensity higher than said background from among the oxygen spectra selected by the step (3);
(6) subtracting said background from the intensity of the oxygen spectra selected again, and obtaining a cumulative spectral intensity of oxygen by accumulating spectra balances;
and
(7) executing quantitative determination using a separately prepared working curve of oxygen concentration and cumulative spectral intensity.

5 more elements

Dependencies are inferred from the claim text.

Method of analyzing oxygen and oxide in metallic material

Life of this patent

Method of analyzing oxygen and oxide in metallic material

Life of this patent

Abstract

Claims10