ICP-OES method for determining content of cerium element in aviation gear steel

Abstract

The invention discloses an ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometer) method for determining the content of cerium in aviation gear steel. The method comprises the following steps: setting working parameters of an inductively coupled plasma emission spectrometer; determining the blank solution and the cerium standard solutions under different concentrations by using an inductively coupled plasma emission spectrometer, and drawing a cerium element concentration standard curve; determining a to-be-determined sample solution by using the inductively coupled plasma emission spectrometer, and then determining the content of the cerium element in the to-be-determined solution by combining the cerium element concentration standard curve. According to the method, the content of the cerium element in the aviation gear steel is accurately measured, meanwhile, it is guaranteed that other elements are accurately measured, no element loss is generated, and compared with a steel mill test result, a sulfuric acid-phosphoric acid fuming method, a perchloric acid fuming method and a spectrophotometric method, the difference is small, precision is high, and accuracy and reliability are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of element content detection and relates to an ICP-OES method for determining the cerium content in aviation gear steel. Background Art

[0002] With the continuous development of aviation industry, aviation gears, as the basic components of aviation power transmission system, serve under complex working conditions such as specific dynamic, high temperature, high speed and heavy load, playing an important role in ensuring power transmission. The reliability of aviation gear components is directly related to the service performance and safety of aircraft. As a new generation of special high-quality steel, 16Cr3NiWMoVNbE gear steel is the mainstream material for transmission components such as gears and axles of my country's aviation engines. It has the advantages of low grain growth tendency, high hardenability, high tensile strength and good toughness and plasticity. The service temperature can reach 350℃, which meets the high temperature and high speed requirements of aviation engine transmission gears. Among them, the light rare earth element cerium (Ce) plays an important role. It can not only desulfurize and deoxidize, but also change the morphology and distribution of inclusions in steel, significantly reduce the content of gas and non-metallic inclusions in steel, refine grains, reduce the brittle transition temperature of steel, and improve the toughness of steel, especially the toughness of steel in the transverse and thickness directions after rolling is more significant.

[0003] In the early 1950s, countries around the world began to study rare earth steel, mainly focusing on the addition of lanthanum and cerium, but the amount of addition must be strictly controlled. Excessive lanthanum and cerium will turn the effect from positive to negative, so it is of great significance to accurately determine the content of lanthanum and cerium in rare earth steel. Rare earth elements are difficult to separate due to their similar properties. The total amount of rare earth is mainly determined by classical chemical analysis methods, including gravimetric method, spectrophotometry, etc. These traditional methods have problems such as complex operation, long analysis time, more interference, and the inability to determine elements at the same time.

[0004] Compared with traditional chemical analysis methods, inductively coupled plasma optical emission spectrometry (ICP-OES) has the characteristics of high precision, low detection limit, wide linear range and simultaneous determination of multiple elements. It overcomes the cumbersome sample pretreatment process of chemical methods, greatly improves the analysis speed, and the analysis results are accurate and reliable, which better meets the requirements of modern production and daily laboratory analysis. It has been widely used in the field of metallurgical analysis. The determination of rare earth elements is also often done by inductively coupled plasma mass spectrometry (ICP-MS). At present, the ICP-OES method has been widely used at home and abroad for the joint determination of various elements in steel. Although there are corresponding standards for the determination of cerium in cast iron and low-alloy steel by ICP-OES, its lower limit of cerium determination is 0.005%, which cannot meet the current scientific research and production needs.

[0005] In summary, the prior art has the problem of low accuracy in measuring the cerium content in gear steel. Summary of the invention

[0006] The purpose of the present invention is to provide an ICP-OES method for determining the cerium content in aviation gear steel, thereby solving the problem of low accuracy in determining the cerium content in gear steel in the prior art.

[0007] The technical solution adopted by the present invention is an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Using an inductively coupled plasma emission spectrometer to measure the sample solution, and then combining it with a standard curve of cerium concentration to determine the cerium content in the solution to be measured.

[0008] The present invention is also characterized in that: The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0009] The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

[0010] The commonly used analytical spectral lines of cerium include 380.152nm, 385.418nm, 393.109nm, 401.239nm, 404.076nm, 413.380nm, 413.765nm, 418.660nm, 422.260nm, 428.994nm, 429.667nm, 446.021nm, 456.236nm, 462.816nm, and 535.353nm.

[0011] The matrix element solution includes a Fe element standard solution; The coexisting element solutions include Mn element standard solution, Si element standard solution, Cr element standard solution, Ni element standard solution, W element standard solution, Mo element standard solution, V element standard solution, Nb element standard solution, and P element standard solution; The analytical element solution includes a cerium element standard solution.

[0012] The best analytical line of cerium is 418.660nm.

[0013] The working pressure is 0.55MPa-0.6MPa.

[0014] The sample solution to be tested is obtained by the following steps: B1. Weigh the aviation gear steel sample and put it into a volumetric bottle; B2. Add hydrochloric acid and nitric acid to the volumetric flask in sequence, heat the volumetric flask, stop heating after the aviation gear steel sample in the volumetric flask is completely dissolved, and cool it to obtain the first sample solution; B3, add citric acid to the first sample solution, heat the volumetric flask, stop heating after the citric acid in the volumetric flask is completely dissolved, and cool to obtain a second sample solution; B4. Add water to the second sample solution and stir evenly to obtain the sample solution to be tested.

[0015] The beneficial effects of the present invention are as follows: the present invention accurately determines the cerium content in aviation gear steel, while ensuring that other elements are accurately determined without any element loss, and compared with the test results of the steel plant, the sulfuric acid-phosphoric acid fuming method, the perchloric acid fuming method, and the spectrophotometric method, the difference is small, the precision is high, and the accuracy and reliability are high; the present invention overcomes the cumbersome sample pretreatment process of the chemical method, improves the analysis speed, and also reduces the cost, and can meet the needs of production analysis and detection; the present invention provides ideas for the ICP-OES method for determining similar rare earth elements in steel or the ICP-OES method for determining cerium elements in steel of similar grades. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a flow chart of the ICP-OES method for determining the cerium content in aviation gear steel. DETAILED DESCRIPTION

[0017] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] ICP-OES method for determining the cerium content in aviation gear steel, such as Figure 1 As shown, the following steps are included: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0019] The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

[0020] The commonly used analytical spectral lines of cerium include 380.152nm, 385.418nm, 393.109nm, 401.239nm, 404.076nm, 413.380nm, 413.765nm, 418.660nm, 422.260nm, 428.994nm, 429.667nm, 446.021nm, 456.236nm, 462.816nm, and 535.353nm.

[0021] The matrix element solution includes Fe element standard solution; the coexisting element solutions include Mn element standard solution, Si element standard solution, Cr element standard solution, Ni element standard solution, W element standard solution, Mo element standard solution, V element standard solution, Nb element standard solution, and P element standard solution; the analysis element solution includes Cerium element standard solution.

[0022] The best analytical line of cerium element is 418.660nm. The working pressure is 0.55MPa-0.6MPa.

[0023] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Using an inductively coupled plasma emission spectrometer to measure the sample solution, and then combining it with a standard curve of cerium concentration to determine the cerium content in the solution to be measured.

[0024] The sample solution to be tested is obtained by the following steps: B1. Weigh the aviation gear steel sample and put it into a volumetric bottle; B2. Add hydrochloric acid and nitric acid to the volumetric flask in sequence, heat the volumetric flask, stop heating after the aviation gear steel sample in the volumetric flask is completely dissolved, and cool it to obtain the first sample solution; B3, add citric acid to the first sample solution, heat the volumetric flask, stop heating after the citric acid in the volumetric flask is completely dissolved, and cool to obtain a second sample solution; B4. Add water to the second sample solution and stir evenly to obtain the sample solution to be tested.

[0025] The present invention determines the optimal analysis conditions by comprehensively considering the instrument working conditions, matrix element interference, coexisting element interference and other aspects; the relative standard deviation of the present invention is less than 0.05%; the detection limit of the elements measured by the instrument is less than 0.001%, the instrument working sensitivity is high, and can meet the test requirements; the spiked recovery rate of each element is between 99.3% and 103.9%, indicating that the determination results of this method are accurate and reliable; The optimal working conditions of the inductively coupled plasma emission spectrometer in the embodiment of the present invention are: plasma power: 1150W; integration time: short wave 15s, long wave 5s; pump speed: 45r / min; carrier gas flow rate: 0.50L / min; auxiliary gas flow rate: 0.5L / min; cooling gas flow rate: 12.5L / min; atomizer gas flow rate: 0.90L / min; vertical observation height: 10.0mm; sample lifting rate: 1.5mL / min; repeated test: 3 times; working gas: high purity argon ≥99.995%, working pressure: 0.55MPa~0.6MPa, circulating cooling water temperature: 20℃, minimum flow rate: 2L / min, exhaust speed: 5.5m / s, sample processing time: 60s, exposure time: 30s; working pressure: 0.55MPa-0.6MPa; The influence of matrix elements on the determination results of Ce element was studied by measuring 1 mg / mL Fe standard solution. The degree of influence of each analytical line is shown in Table 1. There are three levels of interference of matrix elements: no interference, slight interference, and severe interference.

[0026] Table 1 Effect of matrix elements on the analyzed elements in aviation gear steel samples

[0027] The influence of coexisting elements on the determination results of Ce element was studied by measuring 1 mg / mL standard solutions of Mn, Si, Cr, Ni, W, Mo, V, Nb, and P. The degree of influence of each analytical line is shown in Table 2. There are also three levels of interference for Mn, Si, Cr, Ni, W, Mo, V, Nb, and P elements, and there are 8 spectral lines with good comprehensive degree of interference from coexisting elements.

[0028] Table 6 Effect of coexisting elements on Ce in 16Cr3NiWMoVNbE

[0029] Therefore, the optimal analysis spectrum line (418.660nm) of cerium element used in the embodiment of the present invention has better peak shape and better stability, and its background is low and the signal-to-background ratio is high; in addition, the weight of the aviation gear steel sample in the embodiment of the present invention is 0.2g, the heating temperature of the volumetric flask in the embodiment of the present invention is 100 degrees, the hydrochloric acid used is 9ml and the concentration is 1.19 g / mL, the nitric acid is 3mL and the concentration is 1.4g / mL; the citric acid used is 1.5g; the citric acid concentration in the second sample dissolving solution is 0.4 g / mL, and the volume of the second sample solution after dilution with water is 100mL.

[0030] Example 1 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Determine the cerium content in the solution to be measured by using an inductively coupled plasma emission spectrometer and combining it with a cerium concentration standard curve.

[0031] Example 2 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0032] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Determine the cerium content in the solution to be measured by using an inductively coupled plasma emission spectrometer and combining it with a cerium concentration standard curve.

[0033] Example 3 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0034] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Using an inductively coupled plasma emission spectrometer to measure the sample solution, and then combining it with a standard curve of cerium concentration to determine the cerium content in the solution to be measured.

[0035] The sample solution to be tested is obtained by the following steps: B1. Weigh the aviation gear steel sample and put it into a volumetric bottle; B2. Add hydrochloric acid and nitric acid to the volumetric flask in sequence, heat the volumetric flask, stop heating after the aviation gear steel sample in the volumetric flask is completely dissolved, and cool it to obtain the first sample solution; B3, add citric acid to the first sample solution, heat the volumetric flask, stop heating after the citric acid in the volumetric flask is completely dissolved, and cool to obtain a second sample solution; B4. Add water to the second sample solution and stir evenly to obtain the sample solution to be tested.

[0036] Example 4 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0037] The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

[0038] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Determine the cerium content in the solution to be measured by using an inductively coupled plasma emission spectrometer and combining it with a cerium concentration standard curve.

[0039] Example 5 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0040] The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

[0041] The commonly used analytical spectral lines of cerium include 380.152nm, 385.418nm, 393.109nm, 401.239nm, 404.076nm, 413.380nm, 413.765nm, 418.660nm, 422.260nm, 428.994nm, 429.667nm, 446.021nm, 456.236nm, 462.816nm, and 535.353nm.

[0042] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Determine the cerium content in the solution to be measured by using an inductively coupled plasma emission spectrometer and combining it with a cerium concentration standard curve.

[0043] Example 6 This embodiment proposes an ICP-OES method for determining the cerium content in aviation gear steel, comprising the following steps: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, nebulizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

[0044] The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

[0045] The commonly used analytical spectral lines of cerium include 380.152nm, 385.418nm, 393.109nm, 401.239nm, 404.076nm, 413.380nm, 413.765nm, 418.660nm, 422.260nm, 428.994nm, 429.667nm, 446.021nm, 456.236nm, 462.816nm, and 535.353nm.

[0046] The matrix element solution includes Fe element standard solution; the coexisting element solutions include Mn element standard solution, Si element standard solution, Cr element standard solution, Ni element standard solution, W element standard solution, Mo element standard solution, V element standard solution, Nb element standard solution, and P element standard solution; the analysis element solution includes Cerium element standard solution.

[0047] The best analytical line of cerium is 418.660nm.

[0048] S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Determine the cerium content in the solution to be measured by using an inductively coupled plasma emission spectrometer and combining it with a cerium concentration standard curve.

Claims

1. The ICP-OES method for determining the cerium content in aviation gear steel is characterized by: The following steps are involved: S1. Setting the working parameters of the inductively coupled plasma emission spectrometer; S2. Using an inductively coupled plasma emission spectrometer to measure a blank solution and cerium standard solutions at different concentrations and draw a cerium element concentration standard curve; S3. Using an inductively coupled plasma emission spectrometer to measure the sample solution, and then combining it with a standard curve of cerium concentration to determine the cerium content in the solution to be measured.

2. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 1, characterized in that: The working parameters of the inductively coupled plasma emission spectrometer include plasma power, short-wave integration time, long-wave integration time, pump speed, carrier gas flow rate, auxiliary gas flow rate, cooling gas flow rate, atomizer gas flow rate, vertical observation height, sample lifting rate, number of repeated tests, working gas, working pressure, circulating cooling water temperature, minimum flow rate, exhaust speed, sample processing time, exposure time, and analysis spectrum.

3. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 2, characterized in that: The analysis spectrum is obtained by the following steps: A1. Determine the commonly used analytical spectral lines of cerium based on the spectral line data and sensitivity data provided by the instrument spectral line library; A2. According to the chemical components of the aviation gear steel sample, prepare various spectral interference research test solutions including reagent blank solution, matrix element solution, coexisting element solution and analytical element solution; A3. Measure the standard curves of the reagent blank solution, matrix element solution, coexisting element solution, and analytical element solution, and then analyze and determine the best analytical spectrum of cerium element.

4. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 3, characterized in that: The commonly used analysis spectral lines of the cerium element include 380.152nm, 385.418nm, 393.109nm, 401.239nm, 404.076nm, 413.380nm, 413.765nm, 418.660nm, 422.260nm, 428.994nm, 429.667nm, 446.021nm, 456.236nm, 462.816nm, and 535.353nm.

5. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 3, characterized in that: The matrix element solution includes a Fe element standard solution; The coexisting element solutions include Mn element standard solution, Si element standard solution, Cr element standard solution, Ni element standard solution, W element standard solution, Mo element standard solution, V element standard solution, Nb element standard solution, and P element standard solution; The analytical element solution includes a cerium element standard solution.

6. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 3, characterized in that: The best analytical spectrum line of the cerium element is 418.660 nm.

7. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 2, characterized in that: The working pressure is 0.55MPa-0.6MPa.

8. The ICP-OES method for determining the cerium content in aviation gear steel according to claim 1, characterized in that: The sample solution to be tested is obtained by the following steps: B1. Weigh the aviation gear steel sample and put it into a volumetric bottle; B2. Add hydrochloric acid and nitric acid to the volumetric flask in sequence, heat the volumetric flask, stop heating after the aviation gear steel sample in the volumetric flask is completely dissolved, and cool it to obtain the first sample solution; B3, add citric acid to the first sample solution, heat the volumetric flask, stop heating after the citric acid in the volumetric flask is completely dissolved, and cool to obtain a second sample solution; B4. Add water to the second sample solution and stir evenly to obtain the sample solution to be tested.

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