Method of photoelectric spectroscopic determination of dissolved and not dissolved components of element in steel

FIELD: physics.

SUBSTANCE: photoelectric method is added by method of graduation of spectrometer on dissolution degree. Linear calibration dependence is calculated observationally on several gauge samples where the relation of phases is determined. Calibration dependence is not subject to influence of hardware drift and does not demand the operative control of stability.

EFFECT: increase of determination accuracy in comparison with indirect chemical method.

1 dwg

 

The invention relates to analytical chemistry for the quantitative elemental and phase analysis of the composition of substances by optical emission photoelectric spectral analysis of steels. Can be used to determine the components Al and other elements under the control of technological processes of smelting and casting, with certification of finished products at the enterprises of ferrous metallurgy.

Spectral photovoltaic way PIM (peak integral method), when the presence of the "peak" of the curve of uzyskiwania sample is judged on the presence in the metal undissolved phases of the element and the value of this "peak" is the quantity [Slickers K. Automatic Atomik-Emission-spectroscopy. Second Edition. Germani. 1993. 498 R.]. The disadvantage of this method is the lack of calibration of the spectrometer is one of the components, because the intensity measured on the site "peak", also depends on the overall content of the element.

The closest technical solution to the given way is, when one cycle of uzyskiwania measured in equal intervals of time two intensity: the first at the beginning of the cycle, the second after the onset of equilibrium at steady development of the discharge (in the drawing it t1and t2respectively). By comparing the respective intensities I1and I2determine the factor fRA is h that is equal to the ratio (degree) dissolution (f=Cp/Stotal) [Slicers K., Gruber Th. Spectrometric determination of metallic and non-metallic components of steel/ Ferrous metals. 1984. No. 6-7, pp.33-35].

According to the results of the spectral determination of total content of the element (Ctotaland fcalcare dissolved and undissolved components:

Withp=Ctotalfcalc

Withn=Ctotal(1-fcalc)

Known model to obtain fcalc:

where- relative (to the respective intensities of the lines compare Fe) intensity, measured in periods t1and t2respectively;

k, a1and2- constant.

The disadvantages of the method:

the dependence (1) can not be used as a calibration, because it contains two arguments and three coefficients that must be determined experimentally, it is impossible to build graphically on samples with known content components;

- not defined measurement range, its boundaries and how stability control and correction of calibration characteristics (GC) near them to account for instrumental drift, as is customary for photoelectric spectral analysis;

-dependence contradicts the essence of photovoltaic way (according to him I 2proportional Withtotaland the way PIM (according to him I1proportional Withn);

- use relative intensities does not give the usual effect of increasing the stability of the results, since the intensity of the line comparison of Fe measured in the first period, usually experienced fluctuations in antiphase with respect to the corresponding intensity of the element;

- the selection and1and a2in the formula (1) is experimentally verified for individual samples, there is no evidence that this is true for samples with any content item, and another correlation of phases;

- the correctness of the results is assessed by a typical production sample, where the chemical method is set to acid-soluble component of an element that does not necessarily correspond dissolved in the metal component (for example, nitrides of aluminum cyclotorsion, but not dissolved in the metal). The dependence (1) does not allow to adjust the contribution of the phases, if these data were obtained for individual samples of metal, for example, installed x-ray diffraction method, the ratio of oxides and nitrides in the case of aluminum.

The purpose of the proposed solutions address these shortcomings by calibration of the spectrometer by multiple calibration samples installed with the output ratio of the components.

The essence of the proposed method is illustrated as follows.

When the photoelectric spectral analysis of the measured quantity is the integral intensity. On the drawing, which schematically shows the development of the discharge, I1and I2correspond to the squares of the respective areas under the curve.

Level I0divides the I1into two parts: the upper I1Iand the lower I1IIso in line with the essence of PIM only I1Ican be considered an appropriate undissolved component.

Because I1I=I1-I1II, a I1IIis approximately equal to I2at t1=t2it is possible to assume that there is a dependency:

or

As such, the dependency can't be used as an analytical, because the level of absolute intensities depends on the drift of the instrument and changes from time to time by almost half due to contamination of the optics.

If as an internal standard to choose I2measured almost simultaneously with I1you will be taken into account and instrument drift, and changes in signal level due to contamination of the optics.

Then, because I2proportional to the content of Altotalwe can assume that together with the dependence (3) there must be a dependency:

The form of the obtained expression is consistent with the assumption underlying the PIM that when f=1 (100% dissolved aluminum) peak on the curve of uzyskiwania missing, a I1/I2takes a value close to 1.

The dependence of I1/I2from f can be used in the form of (4) to find the calibration dependencies graphically and subsequent calculation of the coefficients of the polynomial, if present it in the form:

Because the estimated calibration dependence is linear, for an experimental determination of sufficient number of samples set to the degree of dissolution.

To cover the entire measuring range selection of calibration samples from a number of production samples and can be performed by measuring the value of I1/I2. The range of variation of this ratio from 1 (maximum dissolution) to 2.0 to 2.5 (about 60%).

For a small number of calibration samples to determine the relationship between the phases can be more accurately by increasing the number of definitions of each phase chemical method.

Involving other methods of quantitative determination of the phase composition in the calibration samples have the opportunity to perform calibration of the spectrometer for metal dissolved component.

The dependence can be used to directly determine the extent of dissolution, regardless of the total content of the element. It is known that the accuracy of direct measurement is always higher than the indirect results.

Use as an internal standard in the same spectral line of the element makes calibration dependence insensitive to the drift of the instrument. Not required to perform procedures operational stability control GC and recalibration, respectively, and a large amount of special samples to perform these operations on each of the spectrometers.

Periodic monitoring provisions of the calibration dependence spend on calibration samples. Minor correction GC may be necessary in the following cases:

- when changing the spark mode, which can lead to changes in the width of the "peak" and the discrepancy between time of measurement;

- when changing the conditions of sample preparation, for example, material or size of the abrasive.

Consumption kalibrovochnyh small samples: one set is sufficient to ensure operation of multiple spectrometers for several years, so the costs of their development pays for itself quickly.

The possibility of calibration of the spectrometer allows to experimentally establish the metrological characteristics of accuracy for measured flat is dissolved and determined by it dissolved constituent element, that, in turn, enables you to use the way for the development of methods KHA.

The method used for determination of dissolved and undissolved constituents of the aluminum in the steel.

Experimentally confirmed the presence of a total straight-line calibration based on the degree of dilution for samples with different content of aluminum (0.005 to 0.40%).

For the two spectrometers "SPECTROLAB-M calibration relationship is established in the form: f%=99-43(I1/I2-1).

Correct development of the discharge control for each uzyskiwania sample relative intensities of Fe measured in these same time intervals. Under normal uzyskiwanie the value of this indicator 0,97-0,99. A significant decrease indicates a hit in the burning zone of large inclusions or other defects of the sample.

The stability of the GC tested for several years: an indicator of long-term reproducibility is not worse than in a series of parallel measurements for all calibration samples.

On the basis of the method developed and validated methodology KHA for process control and finished products. The accuracy of determining the degree of dissolution is 3% abs. Accuracy A1pthrough the degree is not worse than the chemical method.

The invention can be implemented on any EMISSIO the nom spectrometer, where machinery is used PIM: measurement of the intensities in the two time intervals per cycle of uzyskiwania.

The method can be carried out for all elements present in the metal in the form of dissolved and undissolved components when at least two or three calibration samples, the most distinguished according to the criterion proposed in the method, you can set the ratio of the phases in other ways.

How feasible under the conditions applicable to the analytical surface of the samples by PIM.

The method of the photoelectric spectral determination of dissolved and undissolved components in steel, consisting in the fact that during one cycle uzyskiwania register two analytical intensity of the spectral line of the element in two equal length of time: at the beginning of the cycle and during steady-development discharge through these intensity determine the degree of dissolution, then through a degree in General content to identify each of the components of the element, characterized in that the degree of dissolution determined by direct measurement on the calibration dependence found experimentally for several calibration samples in a linear dependence of the degree of dissolution of the difference of the intensities in the first and second time intervals referred to the second intensity, which acts as an internal standard and stabilizes the position dependence in time, so it does not require operational control and correction.



 

Same patents:

FIELD: physics.

SUBSTANCE: process involves plasma generation by multipolar atomic arc excitation source due to uniting of several unipolar arc discharges. Arc discharges are powered by parallel electric chains of unipolar arc discharges with separate capacity load and separate double-wave three-phase rectifier, linked directly (without transformer) to a three-phase alternate current source. One of the discharge electrodes is a cathode for all arcs. The substance under research is introduced into the plasma of multipolar arc discharge with the help of gas jet sucked downwards, and the sucked jet with the powder under investigation is directed downwards at the anode ends. To create favourable conditions for atom emission analysis spectral gas jet velocity in the analytical zone of the source is brought below 4 m/s, unipolar arc power at multipolar arc excitement source being adjusted below 20 A.

EFFECT: higher cost efficiency of the process due to exclusion of insulation transformer.

3 cl, 1 dwg

Generator's arc // 2313079

FIELD: the invention refers to the field of research of chemical and physical properties of a substance and may be used at reduction of emission spectral analysis of the substance.

SUBSTANCE: the essence of the invention is in applying in the generator's arc the feeding of three-phase alternate current. In the mode of constant current the feeding of the generator is applied from a source of three-phase alternate current with a three-phase rectifier of current. At that before the rectifier capacitive loads are located in each phase, in quality of electric loads a set of condensers is applied. Timers are applied for automatic switching of condensers to the basic load of the arc with the aid of contactors in the given moments of burning of the arc with the aim to change the current of the arc during its burning. The generator's block of burning of the arc is made remote with using a thyristor electronic scheme of generation of a spark. For possibility of creation of multi-pole arcs in the body of the generator's arc an additional generator is located similar to the basic generator in which a dividing transformer allowing execute electrically not connected arc charges is installed.

EFFECT: expands functional possibilities, automation of control of the process of the generator's arc, standardization of conditions of output of spectrums and creation of more comfortable conditions of work.

2 cl, 1 dwg

FIELD: testing engineering.

SUBSTANCE: method comprises introducing the pure lubricant to be tested into the layer of capillary-porous material partially coated with a plate electrode and photographing. The material to be investigated is mixed with the pure material in a ratio of 1:10-1:2. The laws of the drop of intensity of high-voltage glow discharge with the distance form the edge of the plate electrode are compared for two samples.

EFFECT: enhanced reliability.

3 cl, 5 dwg

FIELD: analysis of elemental composition of surfaces of solid bodies, it can be used in particular for testing non-conducting materials of dielectrics.

SUBSTANCE: radiation of tested atoms is excited by plasma of gas spark discharge localized along tested surface due to restriction in discharge area above tested surface. The surface provides significant reduction of destroying influence, absence of charging and multiple excitation and irradiation of surface atoms of tested dielectric material.

EFFECT: lowered (improved) limit of detection during testing of elemental composition of surface coatings onto dielectrics; improved locality of analysis.

2 dwg

FIELD: testing of engines.

SUBSTANCE: method comprises measuring the absolute parameters of wear particles in the sample from the oil filter, calculating reduced diagnostic parameters, such as ratings of simple and complex wear particles, total extent of wearing that is the ration of the number of complex particles to the number of simple particles, and extent of wearing for particles made of all elements to be determined.

EFFECT: enhanced reliability of testing.

1 dwg, 1 tbl

FIELD: testing of chemical and physical properties of matters.

SUBSTANCE: according to the method, amount of tested liquid is taken subject to drying and dry residual of liquid is received. Content of chemical elements in dry residual is determined by using method of physical analysis and characteristics of liquid to be analyzed are estimated. As physical method of analysis, the integral-scintillation method is used. As characteristics, the averaged relations of contents of elements to be determined are used, which relations do not depend on conditions of analysis. Non-uniformities available in tested liquid are found. Revealed non-uniformities are subsequently eliminated by using iteration process and results are given while taking revealed non-uniformities into account.

EFFECT: improved precision of analysis.

4 cl, 3 dwg, 2 ex, 3 tbl

FIELD: technology for researching chemical and physical properties of substance, possible use for medicinal, forensic, geological, ecological and other research of substance.

SUBSTANCE: method includes preparing a substance, research is performed over portions of representing share by means of analytical method. During that process registration of spectral emission is performed by means of integration of spectral analytical signals for time, less then double time of short-duration appearance of spectral analytic signals from non-homogeneous portions of substance. Elementary and phase composition of substance is determined with utilization of comparison samples. During calculations background is taken into consideration, while periodical short-duration synchronously accumulated signals are sorted relatively to fluctuations of noise for each one of periodically accumulated spectral signals.

EFFECT: improved sensitivity and precision of analysis.

2 cl, 2 dwg, 2 tbl

FIELD: spectral analysis.

SUBSTANCE: method is based upon thermal atomization of the sample and excitation of atoms by means of electrons emitted by cathode-atomizer. Accelerating voltage is chosen to be lower than threshold of ignition of self-maintained discharge. Voltage of heating of cathode-atomizer should be chosen to be higher than its damage threshold. Damage is prevented and temperature of atomization is specified by means of limiting heat current due to negative feedback for cathode-atomizer radiation flux. Device has chamber with electrodes. Warmed-up electrode is optically connected with photoreceiver. Photoreceiver is connected with photocurrent amplifier. Photocurrent amplifier has feedback with current stabilizer connected between electrode heat source and warmed-up electrode.

EFFECT: reduced limit of detection of elements; improved reproducibility of analysis.

2 cl, 1 dwg

FIELD: multi-parameter control.

SUBSTANCE: method includes forming low-temperature plasma for ionization of gas environment in said volume, two-electrode converter is excited in turns by currents of not less than two different fixed resonance frequencies for forming of different strengths of electromagnetic field near electrodes in accordance to number of fixed frequencies. During scanning of plasma area by converter electric conductivities between electrodes of converter on fixed frequencies and on basis of conduciveness gas composition and also other micro-admixtures are detected and evaluated in volume of environment.

EFFECT: broader functional capabilities, higher efficiency.

3 dwg

FIELD: spectral analysis.

SUBSTANCE: method uses one-electrode high-frequency plasma charge in mode of alternating pulses. In accordance to direction of gas along, perpendicularly or oppositely to plasma-generating electrode different constructions of device burners are used. Recording of radiation spectrums is performed in direction dependent on type of used spectrometer: perpendicular to said generated charge for slit spectrometer and in parallel for diaphragm spectrometer.

EFFECT: higher sensitivity, lower costs.

2 cl, 4 dwg

FIELD: measuring processes and equipment.

SUBSTANCE: method comprises steps of evaporating and atomizing investigated material; exciting its atoms in excitement source plasma; registering spectra of plasma irradiation at using integral-scintillation process for registering spectra and periodically accumulated analytical spectral signals; calculating analysis result. Method is realized at creating conditions for pulse irradiation of atoms of investigated material in excitement source and providing time period of signal accumulation more than 0.1 s.

EFFECT: enhanced responsibility and accuracy of analysis.

3 cl

FIELD: spectral analysis.

SUBSTANCE: method uses one-electrode high-frequency plasma charge in mode of alternating pulses. In accordance to direction of gas along, perpendicularly or oppositely to plasma-generating electrode different constructions of device burners are used. Recording of radiation spectrums is performed in direction dependent on type of used spectrometer: perpendicular to said generated charge for slit spectrometer and in parallel for diaphragm spectrometer.

EFFECT: higher sensitivity, lower costs.

2 cl, 4 dwg

FIELD: multi-parameter control.

SUBSTANCE: method includes forming low-temperature plasma for ionization of gas environment in said volume, two-electrode converter is excited in turns by currents of not less than two different fixed resonance frequencies for forming of different strengths of electromagnetic field near electrodes in accordance to number of fixed frequencies. During scanning of plasma area by converter electric conductivities between electrodes of converter on fixed frequencies and on basis of conduciveness gas composition and also other micro-admixtures are detected and evaluated in volume of environment.

EFFECT: broader functional capabilities, higher efficiency.

3 dwg

FIELD: spectral analysis.

SUBSTANCE: method is based upon thermal atomization of the sample and excitation of atoms by means of electrons emitted by cathode-atomizer. Accelerating voltage is chosen to be lower than threshold of ignition of self-maintained discharge. Voltage of heating of cathode-atomizer should be chosen to be higher than its damage threshold. Damage is prevented and temperature of atomization is specified by means of limiting heat current due to negative feedback for cathode-atomizer radiation flux. Device has chamber with electrodes. Warmed-up electrode is optically connected with photoreceiver. Photoreceiver is connected with photocurrent amplifier. Photocurrent amplifier has feedback with current stabilizer connected between electrode heat source and warmed-up electrode.

EFFECT: reduced limit of detection of elements; improved reproducibility of analysis.

2 cl, 1 dwg

FIELD: technology for researching chemical and physical properties of substance, possible use for medicinal, forensic, geological, ecological and other research of substance.

SUBSTANCE: method includes preparing a substance, research is performed over portions of representing share by means of analytical method. During that process registration of spectral emission is performed by means of integration of spectral analytical signals for time, less then double time of short-duration appearance of spectral analytic signals from non-homogeneous portions of substance. Elementary and phase composition of substance is determined with utilization of comparison samples. During calculations background is taken into consideration, while periodical short-duration synchronously accumulated signals are sorted relatively to fluctuations of noise for each one of periodically accumulated spectral signals.

EFFECT: improved sensitivity and precision of analysis.

2 cl, 2 dwg, 2 tbl

FIELD: testing of chemical and physical properties of matters.

SUBSTANCE: according to the method, amount of tested liquid is taken subject to drying and dry residual of liquid is received. Content of chemical elements in dry residual is determined by using method of physical analysis and characteristics of liquid to be analyzed are estimated. As physical method of analysis, the integral-scintillation method is used. As characteristics, the averaged relations of contents of elements to be determined are used, which relations do not depend on conditions of analysis. Non-uniformities available in tested liquid are found. Revealed non-uniformities are subsequently eliminated by using iteration process and results are given while taking revealed non-uniformities into account.

EFFECT: improved precision of analysis.

4 cl, 3 dwg, 2 ex, 3 tbl

FIELD: testing of engines.

SUBSTANCE: method comprises measuring the absolute parameters of wear particles in the sample from the oil filter, calculating reduced diagnostic parameters, such as ratings of simple and complex wear particles, total extent of wearing that is the ration of the number of complex particles to the number of simple particles, and extent of wearing for particles made of all elements to be determined.

EFFECT: enhanced reliability of testing.

1 dwg, 1 tbl

FIELD: analysis of elemental composition of surfaces of solid bodies, it can be used in particular for testing non-conducting materials of dielectrics.

SUBSTANCE: radiation of tested atoms is excited by plasma of gas spark discharge localized along tested surface due to restriction in discharge area above tested surface. The surface provides significant reduction of destroying influence, absence of charging and multiple excitation and irradiation of surface atoms of tested dielectric material.

EFFECT: lowered (improved) limit of detection during testing of elemental composition of surface coatings onto dielectrics; improved locality of analysis.

2 dwg

FIELD: testing engineering.

SUBSTANCE: method comprises introducing the pure lubricant to be tested into the layer of capillary-porous material partially coated with a plate electrode and photographing. The material to be investigated is mixed with the pure material in a ratio of 1:10-1:2. The laws of the drop of intensity of high-voltage glow discharge with the distance form the edge of the plate electrode are compared for two samples.

EFFECT: enhanced reliability.

3 cl, 5 dwg

Generator's arc // 2313079

FIELD: the invention refers to the field of research of chemical and physical properties of a substance and may be used at reduction of emission spectral analysis of the substance.

SUBSTANCE: the essence of the invention is in applying in the generator's arc the feeding of three-phase alternate current. In the mode of constant current the feeding of the generator is applied from a source of three-phase alternate current with a three-phase rectifier of current. At that before the rectifier capacitive loads are located in each phase, in quality of electric loads a set of condensers is applied. Timers are applied for automatic switching of condensers to the basic load of the arc with the aid of contactors in the given moments of burning of the arc with the aim to change the current of the arc during its burning. The generator's block of burning of the arc is made remote with using a thyristor electronic scheme of generation of a spark. For possibility of creation of multi-pole arcs in the body of the generator's arc an additional generator is located similar to the basic generator in which a dividing transformer allowing execute electrically not connected arc charges is installed.

EFFECT: expands functional possibilities, automation of control of the process of the generator's arc, standardization of conditions of output of spectrums and creation of more comfortable conditions of work.

2 cl, 1 dwg

Up!