Method for determining contents of Al and Nb in high-AlNb titanium alloy based on standard steel and standard adding method

Abstract

The invention relates to the technical field of alloy material analysis, in particular to a method for determining the content of Al and Nb in a high-AlNb titanium alloy based on a standard steel and standard adding method. The method comprises the following steps: selecting standard steel; sampling and dissolving each part of standard steel to prepare a standard steel solution; a working curve is constructed, and analysis spectral lines for analyzing Al and Nb are determined through linear confirmation and calibration confirmation; the Al average value of the high-AlNb titanium alloy is measured on the at least four Al spectral lines, and the Nb average value of the high-AlNb titanium alloy is measured on the at least four Nb spectral lines; and Al and Nb measurement deviation and expansion uncertainty are compared based on a standard steel reverse measurement method. According to the method, the technical problem that the content of Al and Nb in the high-AlNb titanium alloy is difficult to measure due to no mark of the high-AlNb titanium alloy is solved, and the efficiency and accuracy of measuring the content of Al and Nb in the high-AlNb titanium alloy are improved.

Description

Technical Field

[0001] This invention relates to the field of alloy material analysis technology, specifically to a method for determining the Al and Nb content in high-AlNb titanium alloys based on the standard steel spiking method. Background Technology

[0002] In the field of new materials research, high-AlNb titanium alloys (Al 9–12 wt%, Nb 38–45 wt%) are widely used in the manufacture of key components such as compressor disks, integral bladed disks, and casings for aero-engines due to their higher room-temperature plasticity, fracture toughness, and stronger resistance to crack propagation. The Al and Nb contents directly determine the performance of high-AlNb titanium alloys, and their contents must be precisely controlled during the smelting process.

[0003] Currently, due to the lack of standard materials of the same grade for high-AlNb titanium, it is impossible to determine the Al and Nb content in high-AlNb titanium alloys with high precision using XRF and photoelectric direct-reading spectroscopy, which heavily rely on standard materials.

[0004] In the prior art, CN119086533A discloses a standard spiking method for inductively coupled plasma atomic emission spectrometry (ICP-AES), comprising: determining the core constituent elements, target components to be detected, and theoretical ranges of the content of each target component in the test sample; selecting several standard samples, and determining the range of the target component content in each standard sample and the standard sample required for testing, based on any target component to be detected and its corresponding theoretical range; weighing each standard sample, dissolving it separately, adding different volumes of single-standard solution, and making up to volume with deionized water to obtain several test standard solutions; setting up the ICP-AES, and sequentially aspirating the several test standard solutions into the spectrometer to establish analytical curves for each target component; measuring the test sample under the target component analytical curve to directly determine the content of each target component in the test sample. However, this standard spiking method cannot solve the problems of selecting analytical spectral lines for detecting high Al and Nb content, and the interference of other metal ions on Al and Nb under different spectral lines, resulting in low detection accuracy of Al and Nb.

[0005] Therefore, it is of great significance to propose an ICP-OES detection method based on the standard steel spiking method for analyzing Al and Nb in high AlNb titanium alloys. Summary of the Invention

[0006] This invention provides a method for determining the Al and Nb content in high AlNb titanium alloys based on the standard steel spiking method. This method solves the technical problem that it is difficult to determine the Al and Nb content in high AlNb titanium alloys without a grade, and improves the efficiency and accuracy of the determination of Al and Nb content in high AlNb titanium alloys.

[0007] A method for determining the Al and Nb content in high-AlNb titanium alloys based on the standard steel spiking method, wherein the composition and content of the high-AlNb titanium alloy are: Al 9-12 wt%, Nb 38-45 wt%, with the balance being Ti and unavoidable impurities; the method includes the following steps:

[0008] 1) Select titanium alloy standard steel: Select 5 standard steels from certified titanium alloy standard steels, all of which contain Nb and Al components.

[0009] 2) Preparation of standard working curve solution: Add Al standard solution and / or Nb standard solution to each sample of standard steel in step 1) to obtain a standard working curve solution that extends to cover the range of Al and Nb contents in high AlNb titanium alloys.

[0010] 3) Constructing a standard working curve: Load the standard working curve solution from step 2) into ICP-OES sequentially, and add internal standard solution online. Based on the vertical observation method, measure and record the spectral intensities of Al and Nb under the selected spectral lines, and construct the standard working curve by fitting the relationship between spectral intensity and concentration. The internal standard solution includes Sc internal standard solution and Y internal standard solution.

[0011] 4) Linearity verification and calibration: Select the correlation coefficient R from the standard working curve in step 3). 2 For spectral lines with a value ≥0.999, the quality control solution was tested in parallel multiple times using the standard steel reverse measurement method, and the relative standard deviation (RSD%) was calculated. Spectral lines with an RSD% of 0.85–1.0% were selected as the final analytical spectral lines. Among them, the quality control solution was the standard working curve solution with the highest Al or Nb content.

[0012] 5) Preparation of the test sample solution: The high AlNb titanium alloy sample is dissolved in acid to prepare the test sample solution;

[0013] 6) Preparation of internal standard solution: Load the test sample solution from step 5) into ICP-OES, use the final analytical spectral line, and add the internal standard solution online. Based on the vertical observation method, measure and record the spectral intensities of Al and Nb in all test sample solutions in sequence; obtain the Al and Nb contents according to the standard working curve of the same final analytical spectral line.

[0014] In one specific embodiment of the present invention, in step 1), the five standard steel grades are GBW02521, GBW02522, GBW02523, GBW02524 and GBW02525.

[0015] In one specific embodiment of the present invention, in step 2), the concentration of the Al standard solution is 1000 μg / mL; the concentration of the Nb standard solution is 10000 μg / mL.

[0016] In one specific embodiment of the present invention, the Nb standard solution is prepared by dissolving niobium powder NCS1417 with a purity ≥99.99%, and includes:

[0017] Accurately weigh 1.0000g ± 0.0001g of NCS1417 niobium powder; add 5.0mL of H2O and 5.0mL of HNO3, then slowly add 0.5mL of HF dropwise, and heat at 50℃ until completely dissolved. Cool, make up to volume, and shake well.

[0018] In one specific embodiment of the present invention, step 5) establishes a working curve, wherein the selected spectral lines include Al spectral lines and Nb spectral analysis lines; wherein the wavelength of the Al spectral lines is any one of 237.312 nm, 256.798 nm, 266.039 nm, 394.401 nm and 396.152 nm; and the wavelength of the Nb spectral lines is any one of 288.318 nm, 295.088 nm, 309.418 nm, 316.340 nm and 319.498 nm.

[0019] In one specific embodiment of the present invention, in step 3), the fitting includes quadratic fitting and linear fitting; wherein, when the spectral intensity shows an element content ≥20%, the fitting is quadratic fitting; when the spectral intensity shows an element content <20%, the fitting is linear fitting.

[0020] In one specific embodiment of the present invention, in step 3), the concentrations of the Sc single-standard solution and the Y single-standard solution are both 1000 μg / mL; the Sc single-standard solution and the Y single-standard solution are both diluted and brought to volume with 5% HNO3.

[0021] In one specific embodiment of the present invention, in step 4), the relative standard deviation (RSD%) is the ratio of 100 times the standard deviation to the average concentration.

[0022] In one specific embodiment of the present invention, in steps 2) and 5), the acid dissolution is carried out by heating 10 mL of HCl and 0.5 mL of HF at 50 °C until completely dissolved and then brought to a final volume.

[0023] In one specific embodiment of the present invention, the volume adjustment uses deionized water with a conductivity ≤18.255MΩ·cm.

[0024] The beneficial effects of this invention are as follows: This invention establishes a standard working curve for analyzing high-AlNb titanium alloys by adding Al and Nb standard solutions to Nb and Al titanium alloy standard steel. The correlation coefficient of the standard working curve is calculated under at least four spectral lines for linearity confirmation. The quality control sample is backtested under the spectral lines that pass the linearity confirmation for calibration confirmation. After linearity confirmation and calibration confirmation, the final spectral lines for analysis are determined. Using Sc and Y as internal standard solutions can effectively reduce the spectral interference of complex matrix elements in high-AlNb titanium on the elements to be analyzed, thereby improving the efficiency and accuracy of analyzing the Al and Nb content in high-AlNb titanium. Attached Figure Description

[0025] Figure 1 The diagram shows the working curves constructed using the Al spectral line wavelength of 236.705 nm as a specific embodiment of the present invention.

[0026] Figure 2 The diagram shows the working curves constructed using the Al spectral line wavelength of 237.312 nm as a specific embodiment of the present invention.

[0027] Figure 3 The diagram shows the working curve constructed using the Al spectral line wavelength of 394.401 nm as a specific embodiment of the present invention.

[0028] Figure 4 The diagram shows the working curves constructed using the Al spectral line wavelength of 396.152 nm as a specific embodiment of the present invention.

[0029] Figure 5 The diagram shows the working curve constructed using the Nb spectral line wavelength of 288.318 nm as a specific embodiment of the present invention.

[0030] Figure 6 The diagram shows the working curve constructed using the Nb spectral line wavelength of 295.088 nm as a specific embodiment of the present invention.

[0031] Figure 7 The diagram shows the working curves constructed using the Nb spectral line wavelength of 316.340 nm as a specific embodiment of the present invention.

[0032] Figure 8 The diagram shows the working curve constructed using the Nb spectral line wavelength of 319.498 nm as a specific embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0034] A method for determining the Al and Nb content in high-AlNb titanium alloys based on the standard steel spiking method, wherein the composition and content of the high-AlNb titanium alloy are: Al 9-12 wt%, Nb 38-45 wt%, with the balance being Ti and unavoidable impurities; the method includes the following steps:

[0035] 1) Select titanium alloy standard steel: Select 5 standard steel samples from certified titanium alloy standard steels, all of which contain Nb and Al components;

[0036] 2) Preparation of standard working curve solution: Add Al standard solution and / or Nb standard solution to each sample of standard steel in step 1) to obtain a standard working curve solution that extends to cover the range of Al and Nb contents in high AlNb titanium alloys.

[0037] 3) Constructing a standard working curve: Load the standard working curve solution from step 2) into ICP-OES sequentially, and add internal standard solution online. Based on the vertical observation method, measure and record the spectral intensities of Al and Nb under the selected spectral lines, and construct the standard working curve by fitting the relationship between spectral intensity and concentration. The internal standard solution includes Sc internal standard solution and Y internal standard solution.

[0038] 4) Linearity verification and calibration: Select the correlation coefficient R from the standard working curve in step 3). 2 For spectral lines with a value ≥0.999, the quality control solution was tested in parallel multiple times using the standard steel reverse measurement method, and the relative standard deviation (RSD%) was calculated. Spectral lines with an RSD% of 0.85–1.0% were selected as the final analytical spectral lines. Among them, the quality control solution was the standard working curve solution with the highest Al or Nb content.

[0039] 5) Preparation of the test sample solution: The high AlNb titanium alloy sample is dissolved in acid to prepare the test sample solution;

[0040] 6) Preparation of internal standard solution: Load the test sample solution from step 5) into ICP-OES, use the spectral analysis line from step 6), and add the internal standard solution online. Based on the vertical observation method, measure and record the Al and Nb spectral intensities in all test sample solutions in sequence; obtain the Al and Nb contents according to the standard working curve of the same final analytical spectral line.

[0041] In some instances, in step 1), the five standard steel grades are GBW02521, GBW02522, GBW02523, GBW02524 and GBW02525.

[0042] In some instances, in step 2), the concentration of the Al standard solution is 1000 μg / mL; and the concentration of the Nb standard solution is 10000 μg / mL.

[0043] In some instances, the Nb standard solution is prepared by dissolving niobium powder (NCS1417) with a purity ≥99.99%, and includes:

[0044] Accurately weigh 1.0000g ± 0.0001g of NCS1417 niobium powder; add 5.0mL of H2O and 5.0mL of HNO3, then slowly add 0.5mL of HF dropwise, and heat at 50℃ until completely dissolved. Cool, make up to volume, and shake well.

[0045] In some instances, step 5) establishes a working curve, wherein the selected spectral lines include Al spectral lines and Nb spectral analysis lines; wherein the wavelength of the Al spectral lines is any one of 237.312 nm, 256.798 nm, 266.039 nm, 394.401 nm, and 396.152 nm; and the wavelength of the Nb spectral lines is any one of 288.318 nm, 295.088 nm, 309.418 nm, 316.340 nm, and 319.498 nm.

[0046] In some instances, in step 3), the fitting includes quadratic fitting and linear fitting; wherein, when the spectral intensity indicates an element content ≥ 20%, the fitting is quadratic fitting; when the spectral intensity indicates an element content < 20%, the fitting is linear fitting.

[0047] In some instances, in step 3), the concentrations of both the Sc single-standard solution and the Y single-standard solution are 1000 μg / mL; both the Sc single-standard solution and the Y single-standard solution are diluted to volume with 5% HNO3.

[0048] In some instances, in step 4), the relative standard deviation (RSD%) is the ratio of 100 times the standard deviation to the average concentration.

[0049] In some instances, in steps 2) and 5), the acid dissolution is achieved by heating 10 mL of HCl and 0.5 mL of HF at 50°C until completely dissolved and then brought to a final volume.

[0050] In some instances, the volume determination uses deionized water with a conductivity ≤18.255 MΩ·cm.

[0051] In some instances, the quality control solution is selected from five standard working curve solutions, choosing the one with the highest Al or Nb content, including both Al and Nb quality control solutions. When detecting Al content, the Al quality control solution is selected, and the Sc internal standard solution is used as the internal standard for Al analysis. The spectral lines are selected based on the Al spectral lines and their corresponding wavelengths. Similarly, the standard working curves are constructed based on the corresponding spectral lines. When analyzing the Al content in the sample using the Al spectral lines and their wavelengths, the Al content is determined using the standard working curve corresponding to the final Al analysis spectral line. When analyzing the Nb content in the sample using the Nb spectral lines and their wavelengths, the Nb content is determined using the standard working curve corresponding to the final Nb analysis spectral line.

[0052] It should be noted that in this invention, all operations involving hydrofluoric acid are performed in a tetrafluoroethylene container, such as a tetrafluoroethylene beaker.

[0053] Example

[0054] This embodiment provides a method for determining the Al and Nb content in high-AlNb titanium alloys based on the standard steel spiking method, including the following steps:

[0055] 1. Selection of titanium alloy standard steel

[0056] Five certified titanium alloy standard steels containing Nb and Al were selected, namely GBW02521, GBW02522, GBW02523, GBW02524 and GBW02525, and the content of each element is shown in Table 1.

[0057] Table 1. Element content of GBW02521, GBW02522, GBW02523, GBW02524 and GBW02525

[0058]

[0059] 2. Prepare Nb standard solution (10000 μg / mL)

[0060] Accurately weigh 1.0000g ± 0.0001g of NCS1417 (99.99% pure niobium powder) into a 100mL polytetrafluoroethylene beaker, add 5.0mL of H2O and 5.0mL of HNO3, and slowly add 0.5mL of HF dropwise. Heat at 50℃ until completely dissolved (no bubbles are visually observed and no solid remains undissolved). Cool to room temperature (25℃ ± 2℃), transfer to a 100mL plastic volumetric flask, add deionized water (18.25MΩ·cm) to the mark, dilute, make up to volume, and shake well to obtain a 10000μg / mL Nb standard solution.

[0061] 3. Prepare Al standard solution (1000 μg / mL)

[0062] Commercially available GSBG 62006-90 was used as the Al standard solution, with 10% HCl as the medium.

[0063] 4. Establish analytical working curves

[0064] 4.1 Dissolving Titanium Alloy Standard Steel: Accurately weigh 0.1000g ± 0.0005g of GBW02521, GBW02522, GBW02523, GBW02524, and GBW02525 titanium alloy standard steels into a 100mL PTFE beaker. Add 10.0mL of HCl (GR) to each, and add 0.5mL of HF (GR) dropwise. Heat at 50℃ until completely dissolved (visible to show no bubbles and no undissolved solids). Cool to room temperature (25℃ ± 2℃) and transfer to a 100mL plastic volumetric flask (do not dilute to volume).

[0065] 4.2 Preparation of standard working curve solutions: According to the amount of standard steel solution added as shown in Table 2, add different Al standard solutions and / or Nb standard solutions to the 5 standard steel solutions in step 4.1 respectively, add deionized water (18.25 MΩ·cm) to the mark, dilute, make up to volume, and shake well to obtain 5 standard working curve solutions; to obtain 5 standard working solutions that extend to cover the Al and / or Nb content range in high AlNb titanium alloys. The statistical results of Al and Nb content in the standard working solutions are shown in Table 2.

[0066] Table 25 Results of Al and Nb Content in Standard Working Solutions

[0067]

[0068] 4.3 Preparation of quality control solution

[0069] In the series of standard working solutions prepared in step 4.2, the standard working solution with the highest Al and Nb content is selected as the quality control solution, namely GBW02524+6.5Al+30Nb as the quality control solution for Al and GBW02522+5.5Al+45Nb as the quality control solution for Nb.

[0070] 4.4 Preparation of the test sample solution

[0071] Accurately weigh 0.1000g±0.0005g of high AlNb titanium alloy A (production batch number 2025XXX-PX1) into 5 test samples and place them in 100mL polytetrafluoroethylene beakers. Add 10.0mL of HCl (GR) to each sample, and add 0.5mL of HF (GR) dropwise. Heat at 50℃ until completely dissolved (visually no bubbles are generated and no solid remains undissolved). After cooling to room temperature, transfer the solution to a 100mL plastic volumetric flask, add deionized water to the mark, dilute, make up to volume, and shake well to obtain the test sample solution.

[0072] 4.5 Preparation of internal standard solution

[0073] Transfer 1 mL of Sc and Y single standard solutions with a concentration of 1000 μg / mL to 100 mL volumetric flasks, dilute to volume with 5% HNO3, and mix well. At this point, the concentration of the internal standard solution is 1%.

[0074] 5. Construct a standard operating curve:

[0075] The acid blank and 5 standard working curve solutions from step 2) were loaded into ICP-OES in sequence. The internal standard solution was added online using a three-way tube. Based on the vertical observation method, the spectral intensities of Al and Nb under the selected spectral lines were measured and recorded. The standard working curve was fitted using the relationship between spectral intensity and concentration. Elements with a content ≥20% were fitted quadratically, and elements with a content <20% were fitted linearly.

[0076] Four Al working curves were constructed under four Al spectral lines, as shown in the attached figure. Figure 1-4 As shown; Appendix Figure 1 The working curve function under the analysis line at a wavelength of 236.705 nm is f(x) = 1402.0104 × x + 119.8297, and the correlation coefficient R0 is... 2 =0.9984, blank equivalent concentration (BEC) = 0.085%, limit of detection (LoD) = 0.0035%; Appendix Figure 2 The working curve function under the analysis line at a wavelength of 237.312 nm is f(x) = 1610.615 × x + 86.3470, and the correlation coefficient R0 is... 2 =0.9966, blank equivalent concentration (BEC) = 0.054%, limit of detection (LoD) = 0.0002%; Appendix Figure 3 The working curve function at the analysis line of wavelength 394.401 nm is f(x) = 27923.0767 × x + 1248.6268, and the correlation coefficient R0 is... 2 =0.9991, blank equivalent concentration (BEC) = 0.045%, limit of detection (LoD) = 0.0008%; Appendix Figure 4 The working curve function at the analysis line of wavelength 396.152 nm is f(x) = 56635.0831 × x + 4.1761, with a correlation coefficient R0. 2 =0.995, blank equivalent concentration BEC=0.000%, limit of detection LoD=0.0002%;

[0077] Four Nb working curves were constructed under four Nb spectral analysis lines, as shown in the attached figure. Figure 5-8 As shown; Appendix Figure 5 The working curve function at the analysis line of wavelength 288.318 nm is f(x) = -16.4029 × x 2+11923.4016×x+326.3865, correlation coefficient R 2 =0.9994, blank equivalent concentration (BEC) = 0.027%, limit of detection (LoD) = N / A; Appendix Figure 6 The working curve function at the analysis line of wavelength 295.088 nm is f(x) = -20.9294 × x. 2 +99.78.0104×x+191.8843, correlation coefficient R 2 =0.9995, blank equivalent concentration (BEC) = 0.019%, limit of detection (LoD) = N / A; Appendix Figure 7 The working curve function at the analysis line of wavelength 316.340 nm is f(x) = -124.7884 × x 2 +32857.2457×x-17.0065, correlation coefficient R 2 =0.996, blank equivalent concentration (BEC) = -0.001%, limit of detection (LoD) = N / A; Appendix Figure 8 The working curve function at the analysis line of wavelength 319.498 nm is f(x) = -100.1101 × x 2 +33886.7624×x+92.3188, correlation coefficient R 2 =0.9990, blank equivalent concentration BEC=0.003%, limit of detection LoD=N / A;

[0078] The wavelengths (relative intensities) of the four Al spectral lines and their interfering elements (relative intensities) are shown in Table 3; the wavelengths (relative intensities) of the four Nb spectral lines and their interfering elements (relative intensities) are shown in Table 4.

[0079] Table 34 shows the wavelengths (relative intensities) of Al spectral lines and their interfering elements (relative intensities).

[0080]

[0081] Table 44 shows the wavelengths (relative intensities) of the Nb spectral lines and their interfering elements (relative intensities).

[0082]

[0083] 6. Linearity verification and calibration verification

[0084] 6.1 Linearity Confirmation: Based on the standard working curves constructed under the four spectral lines Al and Nb in step 5, calculate the correlation coefficient R of the standard working curves under each spectral line. 2 The correlation coefficient R is selected. 2 Spectral lines with a value ≥0.999 (maximum value) are shown in Table 5;

[0085] Table 5 shows the correlation coefficients R of the standard working curves constructed under the four spectral lines of Al and Nb. 2

[0086]

[0087] 6.2 Calibration Validation

[0088] Using the linearly confirmed spectral lines, the quality control solution prepared in step 2) was tested 10 times based on the standard steel reverse test method, and the relative standard deviation (RSD%) was calculated. The spectral lines with RSD% = 0.85~1.0% were selected as the final analytical spectral lines, as shown in Table 6.

[0089] Table 6. Relative Standard Deviation (RSD%) of Quality Control Solutions

[0090]

[0091] After linearity and calibration confirmation, the wavelength used for analyzing Al was 396.152 nm, and the wavelength used for analyzing Nb was 316.340 nm.

[0092] 7. Analysis of the test sample

[0093] Using the Al and Nb analytical spectral lines of 396.152 nm and 316.340 nm determined in step 6), internal standard solution was added online through a three-way tube. Based on the vertical observation method, the spectral intensities of Al and Nb in all five test sample solutions were measured and recorded sequentially. The average values ​​of the five Al and Nb concentrations below the Al and Nb spectral lines were calculated according to the standard working curve. The statistical results of Al measurement values ​​and their average values ​​are shown in Table 7, and the statistical results of Nb measurement values ​​and their average values ​​are shown in Table 8.

[0094] Table 7. Measured values ​​of Al and their average values.

[0095]

[0096] Table 8. Nb Measurement Values ​​and Average Values

[0097]

[0098] 7. Verification: The Al and Nb contents in GBW02522+5.5Al+45Nb were determined by reverse testing method based on standard steel. The statistical results of Al and Nb contents are shown in Table 9.

[0099] Table 9 Results of Al and Nb reverse detection contents

[0100]

[0101] By backtesting the standard sample (with known Al and Nb contents), at the selected spectral lines of 396.152 nm and 316.340 nm used for Al and Nb analysis, the deviation between the backtested value and the standard value was minimal and less than its expanded uncertainty. The results indicate that the detection results of Al and Nb are accurate and reliable.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for determining the Al and Nb content in high-AlNb titanium alloys based on the standard steel spiking method, characterized in that, The composition and content of the high-AlNb titanium alloy are: Al 9-12wt%, Nb 38-45wt%, with the balance being Ti and unavoidable impurities; the method includes the following steps: 1) Select titanium alloy standard steel: Select 5 standard steel samples from certified titanium alloy standard steel samples, all of which contain Nb and Al components; 2) Preparation of standard working curve solution: Add Al standard solution and / or Nb standard solution to each sample of standard steel in step 1) to obtain a standard working curve solution that extends to cover the range of Al and Nb contents in high AlNb titanium alloys. 3) Constructing a standard working curve: Load the standard working curve solution from step 2) into ICP-OES sequentially, and add internal standard solution online. Based on the vertical observation method, measure and record the spectral intensities of Al and Nb under the selected spectral lines, and construct the standard working curve by fitting the relationship between spectral intensity and concentration. The internal standard solution includes Sc internal standard solution and Y internal standard solution. 4) Linearity verification and calibration: Select the correlation coefficient R from the standard working curve in step 3). 2 For spectral lines with a value ≥0.999, the quality control solution was tested in parallel multiple times using the standard steel reverse measurement method, and the relative standard deviation (RSD%) was calculated. Spectral lines with an RSD% of 0.85–1.0% were selected as the final analytical spectral lines. Among them, the quality control solution was the standard working curve solution with the highest Al or Nb content. 5) Preparation of the test sample solution: The high AlNb titanium alloy sample is dissolved in acid to prepare the test sample solution; 6) Preparation of internal standard solution: Load the test sample solution from step 5) into ICP-OES, use the final analytical spectral line, and add the internal standard solution online. Based on the vertical observation method, measure and record the spectral intensities of Al and Nb in all test sample solutions in sequence; obtain the Al and Nb contents according to the standard working curve of the same final analytical spectral line.

2. The method according to claim 1, characterized in that: In step 1), the five standard steel grades are GBW02521, GBW02522, GBW02523, GBW02524 and GBW02525.

3. The method according to claim 1, characterized in that: In step 2), the concentration of the Al standard solution is 1000 μg / mL; the concentration of the Nb standard solution is 10000 μg / mL.

4. The method according to claim 3, characterized in that: The Nb standard solution is prepared by dissolving niobium powder (NCS1417) with a purity ≥99.99%, and includes: Accurately weigh 1.0000g ± 0.0001g of NCS1417 niobium powder; add 5.0mL of H2O and 5.0mL of HNO3, then slowly add 0.5mL of HF dropwise, and heat at 50℃ until completely dissolved. Cool, make up to volume, and shake well.

5. The method according to claim 1, characterized in that: Step 5) Establish the working curve. The selected spectral lines include Al spectral lines and Nb spectral lines. The wavelength of the Al spectral lines is any one of 237.312 nm, 256.798 nm, 266.039 nm, 394.401 nm, and 396.152 nm. The wavelength of the Nb spectral lines is any one of 288.318 nm, 295.088 nm, 309.418 nm, 316.340 nm, and 319.498 nm.

6. The method according to claim 1, characterized in that: In step 3), the fitting includes quadratic fitting and linear fitting; wherein, when the spectral intensity shows an element content ≥20%, the fitting is quadratic fitting; when the spectral intensity shows an element content <20%, the fitting is linear fitting.

7. The method according to claim 1, characterized in that: In step 3), the concentrations of the Sc single-standard solution and the Y single-standard solution are both 1000 μg / mL; both the Sc single-standard solution and the Y single-standard solution are diluted and brought to volume with 5% HNO3.

8. The method according to claim 1, characterized in that: In step 4), the relative standard deviation (RSD%) is the ratio of 100 times the standard deviation to the average concentration.

9. The method according to claim 1, characterized in that: In steps 2) and 5), the acid dissolution is achieved by heating 10 mL of HCl and 0.5 mL of HF at 50 °C until complete dissolution and then adjusting the volume.

10. The method according to claim 9, characterized in that: The volume determination uses deionized water with a conductivity ≤18.255 MΩ·cm.

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