CN114778521A - Method for measuring high-temperature alloy impurities by hollow cathode emission spectrum - Google Patents

Abstract

The application provides a method for measuring high-temperature alloy impurities by hollow cathode emission spectrum, which comprises the following steps: and S1: detecting the spectral intensity of the element to be detected in the sample at the corresponding analysis wavelength under a first condition; and step S2: using the spectral intensity in step S1, the concentration value C of the element to be measured is determined on the calibration curve_{Total test specimen}(ii) a And S3: detecting the spectral interference value C of matrix elements in a sample_{Sample matrix}(ii) a And step S4: calculating the accurate value of the element to be measured in the sample, C_{Element to be measured}＝C_{Total sample}‑C_{Sample matrix}. According to the method for measuring the impurities of the high-temperature alloy by the hollow cathode emission spectrum, the sample does not need to be consistent with a standard substance matrix.

Description

A kind of method of hollow cathode emission spectrometry to measure impurity of superalloy

technical field

The application belongs to the technical field of alloy detection, and in particular relates to a method for measuring trace impurities in superalloys by hollow cathode emission spectroscopy.

Background technique

At present, superalloys are irreplaceable key structural materials for military and civil aero-engines and hot-end components of gas turbines, and superalloys usually contain 10 to 20 alloying elements, which are strengthened and toughened through solid solution strengthening, precipitation strengthening and grain boundary toughening. , and various process strengthening and toughening methods to ensure that the superalloy has good strength, surface stability and good plasticity from room temperature to high temperature, so the superalloy has a very complex chemical composition. In addition, there are dozens of trace and trace elements in superalloys. Some trace elements are beneficial to the performance of superalloys, while some trace elements have harmful effects on the durability, creep properties and tensile ductility of superalloys. Therefore, the accurate determination of harmful trace impurities in superalloys is very important.

The commonly used methods for the determination of trace impurities in superalloys mainly include hollow cathode spectroscopy (HCD-AES), inductively coupled plasma mass spectrometry (ICP-MS), and atomic absorption spectroscopy (AAS). Among them, ICP-MS and AAS methods are solution analysis, and the sample needs to undergo chemical pretreatment such as acidolysis and dilution, which is easy to introduce pollution. The hollow cathode spectrometry is the analysis of solid samples without chemical pretreatment process, avoiding the introduction of dilution and pollution, high sensitivity, simultaneous determination of multiple elements, high efficiency and low detection cost. However, hollow cathode spectroscopy is susceptible to spectral interference. The common trace impurity elements in superalloys are mainly Pb, As, Sn, Sb, Bi, Se, Te, Ga, In, Tl, Ag, Zn, Cd. In the hot hollow cathode with argon as the carrier gas, the test Such evaporation is mainly thermal evaporation, but also has the effect of cathode sputtering. The experimental results show that the evaporation rules of each impurity element are different. Some elements evaporate quickly and can be evaporated in a short time, some are slower, and some are slower. In order to make all elements fully evaporate and measure at the same time. , it is necessary to lengthen the discharge time under high current. Under these conditions, although most of the matrix elements are refractory elements, they will also be partially evaporated into gaseous atoms under these two evaporation effects. These evaporated matrix elements will have a strong impact on the analysis of impurity elements. Spectral superposition interference and spectral line superposition will seriously affect the accuracy of the analysis results. Therefore, GJB8781.17-2015 stipulates that the hollow cathode spectral analysis requires that the sample matrix and the reference material matrix are basically consistent, mainly to avoid the spectral interference caused by the alloy matrix elements. Influence on the accuracy of test results. However, some impurity elements are seriously interfered by the matrix spectrum, which requires the sample matrix to be completely consistent with the reference material matrix to obtain correct detection results. However, there are many kinds of superalloys, and trace reference materials are extremely limited, which has great limitations on the determination of trace impurities in superalloys.

Therefore, how to provide a method for detecting trace elements in superalloys that does not require a sample and a standard substance with a consistent matrix has become an urgent problem for those skilled in the art to solve.

SUMMARY OF THE INVENTION

Therefore, the technical problem to be solved by the present application is to provide a method for measuring impurities in superalloys by hollow cathode emission spectroscopy, which does not require that the matrix of the sample and the standard substance be consistent.

In order to solve the above problems, the present application provides a method for measuring impurities in superalloys by hollow cathode emission spectroscopy, comprising the following steps:

Step S1: detecting the spectral intensity of the element to be measured in the sample at the corresponding analysis wavelength under the first condition;

Step S2: use the spectral intensity in step S1 to obtain the concentration value C of the element to be tested on the standard curve; the _{total sample} ;

Step S3: detecting the spectral interference value C of the matrix elements in the _{sample matrix} ;

Step S4: Calculate the exact value of the element to be measured in the sample, C _{to be measured element} = C _{total sample} - C _{sample matrix} .

According to the method for determining impurities of superalloy by hollow cathode emission spectrometry of the present application, it is not necessary that the sample and the reference material matrix are consistent.

Further, detecting the spectral interference value C of the _matrix element in the sample in step S3 includes the following steps: burning the sample in the hollow cathode to remove the element to be tested in the sample to form a pure matrix.

Further, in step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} also includes the following steps:

Detecting the spectral intensity generated by the pure matrix at the wavelength of the element to be measured under the first condition;

Using the spectral intensity generated by the pure matrix at the wavelength of the element to be tested, the concentration value C _{sample matrix} produced by the spectral interference of the matrix element in the sample is obtained on the standard curve;

And/or, in step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} includes the following steps: after burning the sample in the hollow cathode, comparing the spectral intensity values after two consecutive burnings , to judge whether the analyte in the sample is completely removed.

Further, burning the sample includes the following steps: burning 2-4 times continuously.

Further, the first condition includes that the instrument used is the LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; and the operating conditions are: the current is 300mA-200s to 500mA-400s; linear control; initial voltage is 0.090V, step 0.00026V;

And/or, the integration time of the element to be measured is 200s-400s;

And/or, the sample passes through a metal sieve with a diameter of 0.28mm-0.45mm;

And/or, the sample surface is smooth.

Further, the preparation method of the standard curve comprises the following steps:

H1 step: detect the spectral intensity I _mark of the element to be measured in the standard substance under the second condition;

H2 step: detect the spectral interference intensity 1 _{standard matrix of} matrix elements in the reference material;

H3 step: calculate the net strength I _{net standard} of the element to be measured in the standard substance, wherein I _{net standard} =1 _standard -1 _{standard matrix} ;

Step H4: take the concentration of the element to be tested in the selected standard substance as the abscissa, and the _net intensity I of the element to be tested as the ordinate to draw a standard curve.

Further, in the H2 step, the spectral interference intensity I of the matrix element in the standard substance is detected. The _{standard substrate} also includes the following steps: burning the standard substance in the hollow cathode to remove the element to be tested in the standard substance to form the standard substrate.

Further, the H2 step detects the spectral interference intensity I of the matrix element in the standard substance. The _{standard matrix} also includes the steps: detecting the standard matrix under the second condition, and the spectral intensity that the standard matrix produces at the wavelength of the element to be measured is the spectral interference intensity. I _{standard matrix} ;

And/or, in the H2 step, the spectral interference intensity I of the matrix element in the standard substance is detected, and the _{standard matrix} further comprises the following steps: after the standard substance is calcined in the hollow cathode, the spectral intensity values after two consecutive calcinations are compared. , to judge whether the analyte in the standard substance is completely removed.

Further, burning the standard substance includes the following steps: burning 2-4 times continuously.

Further, the second condition includes that the instrument used is the LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; and the operating conditions are: the current is 300mA-200s to 500mA-400s; linear control; initial voltage is 0.090V, step 0.00026V; carrier gas pressure 0.12Pa;

And/or, the integration time of the element to be measured is 200s-400s;

And/or, the sample is passed through a metal sieve with a diameter of 0.28mm-0.45mm;

and/or, the surface of the specimen is smooth.

The method for measuring superalloy impurities by hollow cathode emission spectrometry of the present application makes the test more accurate by deducting the spectral interference value of the matrix element, and does not require the matrix of the sample and the standard material to be consistent, so the application scope of the present application is wider.

Detailed ways

The embodiment of the present application discloses a method for measuring impurities in a superalloy by hollow cathode emission spectroscopy, which includes the following steps:

Step S1: detecting the spectral intensity of the element to be measured in the sample at the corresponding analysis wavelength under the first condition;

Step S2: use the spectral intensity in step S1 to obtain the concentration value C of the element to be tested on the standard curve; the _{total sample} ;

Step S3: detecting the spectral interference value C of the matrix elements in the _{sample matrix} ;

Step S4: Calculate the exact value of the element to be measured in the sample, C _{to be measured element} = C _{total sample} - C _{sample matrix} .

The method for measuring impurities in superalloys by hollow cathode emission spectroscopy of the present application can measure trace impurities in superalloys, that is, the method in the present application can be a method for measuring trace impurities in superalloys by hollow cathode emission spectroscopy. The present application can correct the spectral interference produced by the matrix when the hollow cathode emission spectrometry measures the trace impurities of the superalloy. In the examples of the present application, by deducting the spectral interference value C of the matrix element, the _{sample matrix} makes the test more accurate, and the matrix of the sample and the standard substance does not need to be consistent, and the application range is wider. The method of this application is simple and fast, does not require the same matrix as the sample and the reference material, and can give full play to the "trace element direct analysis" of hollow cathode spectroscopy (referring to the sample is directly excited without chemical treatment, and the trace element content is calculated). Advantages, greatly improve the utilization of hollow cathode emission spectrum.

The present application also discloses some embodiments. In step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} includes the following steps: burning the sample in the hollow cathode to remove the element to be tested in the sample. , forming a pure matrix. Through creative research and a large number of experiments, the inventors of the present application have proved that when the content of the analytical elements is less than or equal to 0.5 μg/g, the volatile elements can be removed by continuous burning twice according to the sample analysis procedure. Therefore, the number of times of burning in the present application may be two or more times of continuous burning.

The application also discloses some embodiments. In step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} includes the following steps:

Detecting the spectral intensity generated by the pure matrix at the wavelength of the element to be measured under the first condition;

Using the spectral intensity generated by the pure matrix at the wavelength of the element to be tested, the concentration value C _{sample matrix} generated by the spectral interference of the matrix element in the sample is obtained on the standard curve; that is, the spectrum of the element to be tested in the test sample The pure matrix is detected under the same conditions as the intensity, and the spectral interference intensity is obtained. The spectral interference intensity obtained in this way can correspond to the interference spectrum of the matrix element when the spectral intensity of the element to be measured in the test sample is detected, so that in the step S5, _{the element to be measured} is C=C _{The total sample} -C _{sample matrix is} the exact concentration of the analyte.

The present application also discloses some embodiments. In step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} includes the following steps: after calcining the sample in the hollow cathode, calcining the sample after two consecutive calcinations. The spectral intensity values are compared to determine whether the analyte in the sample is completely removed. Because the element to be tested in the sample will be removed every time of burning, only if there is no element to be tested in the sample, the intensity of the two times of burning before and after will be the same. Judging by the intensity value after burning, if the intensity value is basically the same, it means that the analytical elements are basically removed. Cathode sputtering causes some evaporation losses of the substrate, but this loss is negligible for the entire substrate. Experiments have shown that the amount of matrix elements will be significantly reduced after about 25 times of burning, while the number of burning times to remove the element to be tested in the present application is significantly less than 25 times, so the amount of matrix elements will not be affected.

The present application also discloses some embodiments. The burning of the sample includes the following steps: continuous burning for 2-4 times, which can not only remove the element to be tested in the sample, but also does not affect the total amount of matrix elements. Through creative research and a large number of experiments, the inventors of the present application have proved that when the content of the analytical elements is less than or equal to 0.5 μg/g, the volatile elements can be removed by continuous burning twice according to the sample analysis procedure.

The application also discloses some embodiments, the first condition includes that the instrument used is LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; and the operating conditions are: the current is 300mA-200s to 500mA-400s; linear control; initial voltage is 0.090V, the step is 0.00026V; the carrier gas pressure is 0.12Pa.

The application also discloses some embodiments, the integration time of the element to be measured is 200s-400s;

The application also discloses some embodiments, the sample passes through a metal sieve with a diameter of 0.28mm-0.45mm;

The application also discloses some examples where the surface of the sample is smooth.

Specifically, the integration time of As, Se, Sn, and Bi was 200 seconds, and the integration time of Pb, Ag, Cd, Ga, In, Tl, Sb, Te, and Zn was 400 seconds; the sieve hole diameters of the samples were 0.28 mm and 0.45mm metal sieve, and the surface is smooth and powder-free. The matrix elements that produce spectral interference are mainly Cr, Ni, Mo, Ti and Co, which are all non-volatile substances, and the maximum temperature of the hot hollow cathode discharge cathode is only about 2000 °C, so the volatilization of these matrix substances is mainly due to cathode sputtering. produced by radiation. The sputtering rate, that is, the number of atoms sputtered from the surface of the cathode after being collided by positive ions, has a great relationship with the surface state, geometric shape, carrier gas pressure, and discharge voltage of the cathode. In order to ensure that the sputtering rate of the sample and the calcined pure substrate is consistent to the greatest extent, that is, the deduction of the substrate interference value is more accurate, the inventor of the present application has studied the main influence by using a standard substance with a certain value and a large number of conditions. The influence of factors on sputtering rate, the optimal sample condition and the optimal analysis parameters were determined. The study found that the surface of the sample is rough or the sample has obvious edges and corners, or the powder produced by the sample during the crushing process adheres to the surface of the sample, and the sputtering will increase. . In the best sample state, the experiment proves that the carrier gas pressure is 0.12Pa, the initial voltage is 0.090V, and the element content in the standard material is measured, that is, the content of the matrix interference value after deducting the calcination. _{Element to be measured} = C _{Total Specimen} - C _{Specimen Matrix is} closest to the standard value. The four elements of Se, As, Sn, and Bi are too strongly interfered by the matrix. For trace analysis, a slight fluctuation in the interference value detected by the pure matrix after burning will have a greater impact on the final detection result. . In the experiment, it is found that the sputtering of the matrix elements is mainly concentrated in the last 200 seconds of the cathode discharge. Therefore, in order to more accurately deduct the matrix interference, the integration time of these four elements is up to the first 200 seconds of the cathode discharge, although some sensitivity is sacrificed. , but can greatly improve the accuracy of the analysis.

The application also discloses some embodiments, and the preparation method of the standard curve includes the following steps:

H1 step: detect the spectral intensity I _mark of the element to be measured in the standard substance under the second condition;

H2 step: detect the spectral interference intensity 1 _{standard matrix of} matrix elements in the reference material;

H3 step: calculate the net strength I _{net standard} of the element to be measured in the standard material, wherein I _{net standard} =I _standard -I _{standard matrix} .

Step H4: take the concentration of the element to be tested in the selected standard substance as the abscissa, and the _net intensity value I of the element to be tested as the ordinate to draw a standard curve.

The application also discloses some embodiments. In the H2 step, the spectral interference value I of the matrix element in the standard substance is detected. The _{standard matrix} further includes the following steps: burning the standard substance in the hollow cathode to remove the element to be tested in the standard substance. , forming a standard matrix. Similarly, burning the standard material can also make the element to be tested volatilized and removed.

The application also discloses some embodiments. In the H2 step, the spectral interference intensity of the matrix element in the standard substance is detected. The _{standard matrix} further includes the following steps: detecting the standard matrix under the second condition, and the standard matrix is generated at the wavelength of the element to be tested. The spectral intensity is the spectral interference intensity I standard matrix.

The present application also discloses some embodiments. The burning of the standard material includes the following steps: burning continuously for 2-4 times. Under this number of times, the total amount of the matrix is basically not affected, and the elements to be detected can be completely removed.

The application also discloses some embodiments. In the H2 step, the spectral interference intensity I of the matrix element in the standard substance is detected. The _{standard matrix} further includes the following steps: after the standard substance is calcined in the hollow cathode, calcinations are performed for two consecutive calcinations. The spectral intensity values are compared to determine whether the analyte in the standard material is completely removed. In the analysis process of the present application, it can be judged according to the intensity values after two consecutive burnings. If the intensity values are basically the same, it means that the analysis elements are basically removed. Cathode sputtering causes some evaporation losses of the substrate, but this loss is negligible for the entire substrate. Experiments have shown that the amount of matrix elements will be significantly reduced only when the amount of calcination is about 25 times. Impurities mentioned in this application are trace impurities.

The application also discloses some embodiments, the second condition includes that the instrument used is LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; and the operating conditions are: the current is 300mA-200s to 500mA-400s; linear control; initial voltage is 0.090V, the step is 0.00026V; the carrier gas pressure is 0.12Pa;

The application also discloses some embodiments, the integration time of the element to be measured is 200s-400s;

The application also discloses some embodiments, the sample passes through a metal sieve with a diameter of 0.28mm-0.45mm;

The application also discloses some examples where the surface of the sample is smooth.

The integration time of As, Se, Sn, Bi is 200 seconds, and the integration time of Pb, Ag, Cd, Ga, In, Tl, Sb, Te, Zn is 400 seconds; the sieve diameters of the samples are 0.28 mm and 0.45 mm metal sieve, and the surface is smooth and powder-free.

The method for measuring impurities in superalloys by hollow cathode emission spectrometry of the present application does not require the matrix of the sample and the reference material to be consistent, and can effectively measure the impurity content in the superalloy. The method for trace impurities in superalloys with inconsistent standard material matrix can measure the common volatile impurities Pb, As, Sn, Sb, Bi, Se, Te, Ga, In, Tl, Ag, Zn, Cd in superalloys. It is simple and fast, and the detection results are basically consistent with the detection results of ICP-MS.

The specific method steps are as follows:

1. Instrument Preparation

Instrument model: LPG-2000 vacuum type fixed channel hollow cathode photoelectric spectrometer, the discharge current is controlled in stages from low to high.

2. Sample Preparation

The standard sample and the sample to be tested are sieved, and the sieve diameters are 0.28mm and 0.45mm respectively. If the sample produces metal powder during the crushing process, the powder attached to the metal chips can be cleaned by ultrasonic and dried. Both the standard sample and the sample to be tested are weighed as two parallel samples with a weight of 50 mg.

3. Standard series

Superalloy trace standards.

4. Analysis process

Put each sample into the burned spectrally pure graphite electrode, insert the electrode with the sample into the cathode end of the hollow cathode lamp, and the spectral intensity of the element to be measured is collected and tested by a photomultiplier tube.

1) Establishment of calibration curve

Standard matrix: The standard matrix refers to the pure matrix of the superalloy that does not contain the element to be tested. The standard matrix and the sample to be tested are tested under the same conditions, the spectral intensity generated at the wavelength of the element to be tested is the interference intensity of the matrix element, and the correction can be achieved by deducting the corresponding interference intensity from the intensity of each element to be tested in the sample The purpose of matrix spectral interference.

Fabrication of standard matrix: The evaporation process of elements in the hollow cathode and the excitation process of atoms are carried out in the electrode (cathode hole), and the atomic vapor will be evacuated by vacuum after staying in the cathode hole for about 1 second. Experiments show that when the content of the element to be measured is less than or equal to 0.5μg/g, the volatile elements can be removed by burning twice continuously according to the sample analysis procedure. In the actual analysis process, it can be judged according to the intensity values after two consecutive burnings. If the intensity values are basically the same, it means that the elements to be tested are basically removed. Cathode sputtering causes some evaporation losses of the substrate, but this loss is negligible for the entire substrate. Experiments show that the amount of matrix elements will be significantly reduced when calcined for about 25 times.

The specific production method of the standard matrix: select a standard material sample with the lowest impurity element content in the standard series used, weigh 50 mg, and burn it continuously (usually 2 to 4 times) in the hollow cathode. If the strength of the matrix is the same, the volatile elements to be tested have been removed, and the fired graphite electrode is used as the standard matrix of the standard curve.

Standard curve: measure the emission intensity of the element to be measured in the standard series of samples under the selected analysis conditions, and measure the interference intensity at the wavelength of the element to be measured from the standard matrix prepared by the above method under the same conditions. The intensity value of each element to be tested in the standard series must deduct the interference intensity of the corresponding standard matrix above to obtain the net emission intensity of each element to be tested, and then draw the calibration with the net intensity as the ordinate and the concentration as the abscissa curve. The calibration curve thus obtained is the net intensity versus concentration of the analyte without matrix spectral interference.

2) Sample measurement

Pure Matrix of Specimen: The pure matrix of the specimen is fired in the same way as the standard matrix. The samples of different grades should prepare their own pure matrix.

Specific measurement methods:

① Weigh the parallel samples and put them into the burned spectrally pure graphite electrodes respectively, insert the electrode containing the sample into the cathode end of the hollow cathode lamp, and the spectral intensity of the element to be measured is collected and tested by a photomultiplier tube. Calculate the concentration of the element to be tested on the above standard curve, the concentration value at this time is the concentration value C _{total sample} with the spectral interference of the analytical sample matrix.

② The pure matrix of the samples of different brands is used as the sample to detect, and the superimposed interference value C _{sample matrix} produced by the spectra of the different brands of matrix is obtained on the standard curve;

③ The content of the element to be tested in the sample can be obtained by subtracting the interference value of each element produced by the pure matrix measured in the second step from the concentration value of each element to be tested measured in the first step.

That is, C _{analyte element} =C _{total sample} -C _{sample matrix} .

Example

In this example, the method of the present application is used to determine the impurity element content of 4 superalloy samples, including one K438 superalloy sample, 2 K417G superalloy samples and one K4800 superalloy sample. Use K3 series standard material as standard curve. That is, in this embodiment, K3 is a standard substance, and K438, K417G and K4800 are three different substances to be tested, respectively. K3 standard material and K438, K417G and K4800 are superalloys of different grades. The types and contents of matrix elements of each superalloy are different. The main chemical compositions are shown in Table 1.

Table 1 Main chemical components of K3, K438, K417G (wt%)

K3 K438 K417G K4800 Cr 10.0-12.0 15.5-16.5 8.5-9.5 13.7-14.3 Al 5.0-6.0 3.2-3.7 4.8-5.7 2.8-3.2 Mo 3.8-4.5 1.5-2.0 2.5-3.5 3.7-4.3 Co 4.5-6.0 8.0-9.0 9.0-11.0 9.0-10.0 Ti 2.0-3.0 3.0-3.5 4.1-4.7 4.8-5.2 V 0.6-0.9 Nb 0.6-1.1 W 4.8-4.5 2.4-2.8 3.7-4.3 Ni Remain Remain Remain Remain

The instruments and operating conditions used in this embodiment are as follows:

Instrument model: LPG-2000 vacuum type fixed channel hollow cathode photoelectric spectrometer

Operating conditions: current 300mA-200s, 500mA-400s, linear control step 0.00026V

Initial voltage: 0.090V

The specific analysis steps are as follows:

1. Sample preparation: sample preparation according to GB/T 222 standard. After the sample is crushed, it is screened into particles with a diameter of 0.28mm to 0.45mm using a metal standard sieve. The sieved standard sample and each alloy sample are weighed as two parallel samples, and each sample weighs 50 mg; the parallel sample refers to the same sample weighed in two copies, that is, each alloy and standard sample are weighed in two. It has its own sample 1 and sample 2, which are tested twice under the same testing conditions, and the results are averaged, which can effectively reduce random errors.

2. Spectral pure graphite electrode: outer diameter 6mm, inner diameter 3mm, hole depth 30mm, total length 41mm.

3. Pretreatment of the graphite electrode: Before loading the sample, insert the empty electrode into the cathode tungsten wire of the hollow cathode lamp, discharge it in an argon atmosphere, and carry out high-temperature burning and degassing, moisture and impurity elements. Gradually increase the current to the set three-stage current (400mA, 600mA, 750mA), burn the electrode until the discharge is stable, stop the discharge when the current rises to 750mA and can maintain a stable discharge for 1min, and take out the electrode for use.

4. Superalloy reference material: K3 series reference material is used, there are eight reference materials from K3-1 to K3-8, and the content is shown in Appendix B.

5. Analysis process: Put each sample into the burned spectroscopic pure graphite electrode, insert the electrode containing the sample into the cathode end of the hollow cathode lamp, and select the recommended spectral line of the instrument for the spectral line of the element to be measured. The spectral intensity of the measured element was collected and tested by a photomultiplier tube.

1) Standard matrix: The standard series of pure matrix is fired with the standard material with the lowest impurity content. Except As and Sn, the impurity content of K3-1 is the lowest, and it is the most suitable for preparing standard matrix. For the volatilized element to be measured, this fired graphite electrode was used as the standard matrix for the standard curve. The emission spectrum intensity values of each analytical element of the four firings are listed in Table 2. It can be seen from Table 2 that the emission intensities of each analytical element after the third and fourth firings have basically reached the same level, indicating that the element to be tested is eliminated by volatilization. , so K3-1 can be fired three times.

Table 2K3-1 Emission spectrum intensity of each analytical element in four firings

Analysis element first firing second firing third firing fourth firing Pb 1878983 512362 462876 459988 Sn 139442 122310 103365 102729 Sb 3019878 1929097 1887528 1894412 Bi 6510444 3067006 2818880 2806439 As 124155 75855 70068 69826 Te 268092 119089 104213 103876 Ga 2634321 1208839 1168220 1165483 In 1731137 624050 615404 612339 Cd 799407 355255 348711 346936 Tl 4004677 2071205 2052430 2052669 Se 268682 191379 174242 173898 Zn 1632393 512781 492471 492078

2) Establishment of the standard curve: According to the reference content of the impurity element to be measured, three or more standard substances are selected from the 8 standard substances of the K3 series to draw the standard curve. The intensity value of each element to be tested in the standard sample must deduct the above-mentioned standard matrix interference intensity value to obtain the I _{net standard} , and then draw the standard curve with the net intensity as the ordinate and the concentration as the abscissa.

3) Making the pure matrix of the alloy sample to be tested: The pure matrix of K438, K417G and K4800 is fired in the same method as the standard matrix.

4) Sample measurement:

①The weighed parallel alloy samples were put into the burnt spectroscopic pure graphite electrode respectively, the electrode containing the sample was inserted into the cathode end of the hollow cathode lamp, and the spectral intensity of the element to be measured was collected by a photomultiplier tube test. Calculate the concentration of the element to be tested on the above standard curve, the concentration value at this time is the concentration value C _{total sample} with the spectral interference of the analytical sample matrix.

② The pure matrix of alloy samples of different grades is used as a sample for detection, and the superimposed interference value C generated by the spectrum of the different grades of matrix is obtained on the standard curve. _{Sample matrix} ;

③ The concentration value of each element to be tested measured in the first step is subtracted from the interference concentration of each element produced by the sample matrix measured in the second step to obtain the content of the element to be tested in the sample, that is, C _{to be Detector} = C _{total sample} - C _{sample matrix} .

Hollow cathode spectral detection data of one K438 sample, two K417G samples and one K4800 sample (one set of parallel data for each sample) and the use of inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption Spectroscopy (AAS) and glow discharge mass spectrometry (GDMS) detection data are listed in Table 3, Table 4, Table 5, and Table 6 below:

Table 3 K438 sample detection data (%)

Table 4 1#K417G sample detection data (%)

Table 5 2#K417G sample detection data (%)

Table 6 K4800 sample test data (%)

In the above Table 3-6, the total amount and the pure matrix were detected by two samples, one sample was fired into the pure matrix, and the interference value was measured; the other sample was directly detected, and the total amount of interference was measured; parallel The sample mean is the average of Sample 1 and Sample 2.

Through the above examples, it can be seen that the application of the hollow cathode emission spectrum to measure the content of trace impurity elements in the superalloy effectively and accurately corrects the interference of the matrix superposition spectrum, and can measure the common volatile trace impurity elements in the superalloy, The data are basically consistent with other analysis methods. The analysis method is simple, fast, accurate, and has low detection cost, and can be popularized and used in daily detection work.

Appendix A

(informative appendix)

Relative intensities of hollow cathode and atomic spectra (simultaneous effects of sputtering and thermal evaporation)

The above Appendix A shows the interference of alloying elements of superalloys to the measured elements.

It can be easily understood by those skilled in the art that, on the premise of no conflict, the above advantageous manners can be freely combined and superimposed.

The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. Inside. The above are only the preferred embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the technical principles of the present application, several improvements and modifications can also be made, and these improvements and modifications should also be It is regarded as the protection scope of this application.

Claims (10)

1. a method for measuring superalloy impurities by hollow cathode emission spectrometry, is characterized in that, comprises the steps: Step S1: detecting the spectral intensity of the element to be measured in the sample at the corresponding analysis wavelength under the first condition; Step S2: use the spectral intensity in the step S1 to obtain the concentration value C of the element to be measured on the standard curve; the _{total sample} ; Step S3: detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} ; Step S4: Calculate the exact value of the element to be tested in the sample, C _{to be tested} , where C _{to be tested} = C _{total sample} - C _{sample matrix} . 2. according to the method for measuring superalloy impurities by hollow cathode emission spectrometry described in claim 1, it is characterized in that, in described S3 step, detect the spectral interference value C _{sample matrix of} matrix element in described sample comprises the following steps: The sample is fired in a hollow cathode to remove the analyte from the sample to form a pure matrix. 3. according to the method for measuring superalloy impurities by hollow cathode emission spectrometry described in claim 2, it is characterized in that, in described S3 step, detect the spectral interference value C _{sample matrix of} matrix element in described sample also comprises the following steps : Detecting the spectral intensity generated by the pure matrix at the wavelength of the element to be detected under the first condition; Using the spectral intensity generated by the pure matrix at the wavelength of the element to be tested, the concentration value C _{sample matrix} generated by the spectral interference of the matrix element in the sample is obtained on the standard curve; And/or, in the step S3, detecting the spectral interference value C of the matrix element in the sample, the _{sample matrix} includes the following steps: after calcining the sample in the hollow cathode, calcining the sample for two consecutive times. The spectral intensity values are compared to determine whether the analyte in the sample is completely removed. 4 . The method for measuring impurities in superalloys by hollow cathode emission spectroscopy according to claim 2 , wherein the burning of the sample comprises the following steps: burning 2-4 times continuously. 5 . 5. according to the method for measuring superalloy impurities by hollow cathode emission spectrometry described in claim 1, it is characterized in that, the instrument that described first condition comprises adopts is LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; The conditions are: the current is 300mA-200s to 500mA-400s; linear control; the initial voltage is 0.090V, the step is 0.00026V; the carrier gas pressure is 0.12Pa; And/or, the integration time of the element to be measured is 200s-400s; And/or, the sample passes through a metal sieve with a diameter of 0.28mm-0.45mm; And/or, the sample surface is smooth. 6. the method for measuring superalloy impurities according to the hollow cathode emission spectrometry described in claim 1, is characterized in that, the preparation method of described standard curve comprises the steps: H1 step: detect the spectral intensity I _mark of the element to be measured in the standard substance under the second condition; H2 step: detect the spectral interference intensity 1 _{standard matrix of} matrix elements in the standard substance; H3 step: calculate the net strength I _{net standard} of the element to be measured in the standard material, wherein I _{net standard} =1 _standard -1 _{standard matrix} ; Step H4: take the concentration of the element to be tested in the standard substance as the abscissa, and the _net intensity I of the element to be tested as the ordinate to draw a standard curve. 7. according to the method for measuring superalloy impurity according to hollow cathode emission spectrometry described in claim 6, it is characterized in that, in described H In step, detect the spectral interference intensity I _{standard matrix of} matrix element in described standard substance also comprises the steps: The standard substance is fired in the hollow cathode to remove the element to be tested in the standard substance to form a standard matrix. 8. according to the method for measuring superalloy impurities by hollow cathode emission spectrometry described in claim 7, it is characterized in that, in described H In the step, detect the spectral interference intensity I _{standard matrix of} matrix element in described standard substance also comprises the steps: Detecting the standard matrix under the second condition, the spectral intensity generated by the standard matrix at the wavelength of the element to be measured is the spectral interference intensity I _{standard matrix} ; And/or, detecting the spectral interference intensity I of the matrix element in the standard substance in the step H The _{standard matrix} further comprises the following steps: after the standard substance is calcined in the hollow cathode, after two consecutive calcinations The spectral intensity values are compared to determine whether the analyte in the standard substance is completely removed. 9 . The method for measuring impurities in superalloys by hollow cathode emission spectrometry according to claim 7 , wherein the burning of the standard material comprises the following steps: burning continuously for 2-4 times. 10 . 10. The method for measuring superalloy impurities by hollow cathode emission spectrometry according to claim 6, wherein the second condition comprises that the instrument employed is a LPG-2000 model vacuum type fixed channel hollow cathode photoelectric spectrometer; and operating The conditions are: the current is 300mA-200s to 500mA-400s; linear control; the initial voltage is 0.090V, the step is 0.00026V; the carrier gas pressure is 0.12Pa; And/or, the integration time of the element to be measured is 200s-400s; And/or, the sample passes through a metal sieve with a diameter of 0.28mm-0.45mm; And/or, the sample surface is smooth.