Method for determining yttrium in medium-low alloy steel

Abstract

This invention discloses a method for determining yttrium in low- and medium-alloy steel, comprising: weighing a certain amount of steel sample, dissolving the sample in a 100 mL volumetric flask using a nitric acid-hydrochloric acid mixture, cooling the solution, and then diluting and mixing it. The solution is then nebulized and introduced into an inductively coupled plasma mass spectrometer (ICP-MS) to determine the yttrium content. Finally, a working curve is plotted using yttrium standard solutions with concentration gradients. The intensity ratio of the analyte to the internal standard reference line in the calibration curve solution is measured in ascending order. A calibration curve is plotted with the concentration of the analyte on the x-axis and the intensity ratio of the analyte to the internal standard reference line on the y-axis, outputting the concentration of yttrium in the steel. The purpose of this invention is to provide a simple, rapid, accurate, and interference-resistant method for determining the yttrium content in low- and medium-alloy steel using ICP-MS, which requires no special instrumentation.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical analysis technology, and particularly relates to a method for determining yttrium in medium and low alloy steel. Background Technology

[0002] Adding yttrium to low- and medium-alloy steel can significantly optimize steel performance through multiple mechanisms, including purifying molten steel, refining microstructure, and regulating interfaces, thus significantly improving the overall performance of low- and medium-alloy steel, particularly in corrosion resistance, toughness, and weldability. With the maturity and cost reduction of rare earth addition technology, yttrium-containing steel has already achieved industrial application in construction, marine, and automotive fields. In the future, through the deep integration of basic research and process innovation, yttrium is expected to play a greater role in strategic fields such as high-end equipment manufacturing and new energy, becoming a key element in promoting the green and high-performance development of steel materials. Therefore, accurately analyzing the yttrium content in low- and medium-alloy steel is of great significance. Currently, there are no specific standards and methods for detecting yttrium in low- and medium-alloy steel in the metallurgical analysis industry. Based on this situation, this invention proposes a method for detecting the yttrium content in low- and medium-alloy steel.

[0003] Invention patent 202010644618.7 discloses a method for determining the content of silicon, manganese and titanium in ferrophosphorus by ICP-AES. The method of the present invention uses salt, nitric acid and acid to dissolve the sample, and treats the residue with sodium carbonate-boric acid mixed flux and then uses inductively coupled plasma to determine the content of silicon, manganese and titanium. This method can dissolve the sample at one time and determine multiple elements simultaneously. The sample is completely dissolved and has the advantages of simple operation, short analysis time and good accuracy.

[0004] Invention patent 202410908291.8 discloses a method for determining low levels of titanium, molybdenum, and tungsten in stainless steel. A certain amount of sample is weighed, dissolved in nitric acid-hydrochloric acid, transferred to a volumetric flask, and diluted to volume before shaking. The solution is then nebulized and introduced into an inductively coupled plasma mass spectrometer (ICP-MS) to measure the intensity of the mass signal of the analyte. Finally, the concentration of the corresponding element in the analyte is output using a working curve obtained from a standard reference of known concentration. The purpose of this invention is to provide a method for determining low levels of titanium, molybdenum, and tungsten in stainless steel. This method has been applied in production practice and is an effective, accurate, and practical method. Summary of the Invention

[0005] To address the shortcomings of existing detection methods, the purpose of this invention is to provide an ICP-MS method for determining the yttrium content in low-alloy steel that is simple to operate, fast to detect, highly accurate, has strong anti-interference capabilities, and requires no special instruments. This method meets the needs of rapid quality control in steelmaking and high-precision production of high-end steel products, and broadens the applicability and flexibility of the method.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This invention discloses a method for determining yttrium in low-alloy steel. A 0.1000g steel shaving sample is weighed and placed in a 100mL volumetric flask. A mixed acid solution of hydrochloric acid and nitric acid (20mL) is added, and the mixture is heated at low temperature until completely dissolved. After cooling to room temperature, water is added to bring the volume to a final volume, and the solution is shaken well to obtain the test solution. The solution is nebulized and introduced into an inductively coupled plasma mass spectrometer (ICP-MS) to determine the yttrium content. Finally, a working curve is plotted using yttrium standard solutions with varying concentration gradients. The intensity ratio of the analyte to the internal standard reference line in the working curve solution is measured from low to high. A calibration curve is plotted with the concentration of the analyte on the x-axis and the intensity ratio of the analyte to the internal standard reference line on the y-axis, outputting the concentration of yttrium in the steel.

[0008] Furthermore, the steel sample was weighed to an accuracy of 0.0002g.

[0009] Furthermore, the volume ratio of the mixed acids is: hydrochloric acid + nitric acid + water = 1 + 1 + 3.

[0010] Furthermore, the temperature of the low-temperature heating is 240-260℃.

[0011] Furthermore, the low-temperature heating time is 15-30 minutes.

[0012] Furthermore, the low-temperature heating temperature is 250°C, and the low-temperature heating time is 20 minutes.

[0013] Further, add equal amounts of mixed acid to five 100 mL volumetric flasks, then dilute the yttrium standard solution stepwise into the volumetric flasks as needed, make up to volume, shake well, and plot the working curve based on the corresponding yttrium content values.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] Accurate analysis of yttrium content in low- and medium-alloy steels is crucial for fundamental research and technological innovation. Therefore, this invention proposes a method for detecting yttrium content in low- and medium-alloy steels. This method has been applied in production practice, yielding accurate results. It is an effective and practical method that can be widely applied in the metallurgical industry and related research institutions. Detailed Implementation

[0016] A method for determining yttrium in medium and low alloy steel, comprising:

[0017] 1. Scope

[0018] This method specifies the determination of yttrium content in low- and medium-alloy steels using inductively coupled plasma mass spectrometry.

[0019] Measurement range: Yttrium: 0.0001%–0.02%.

[0020] 2. Method Summary

[0021] A certain amount of steel sample was weighed and dissolved in a 100 mL volumetric flask using a nitric acid-hydrochloric acid mixture. After the solution cooled, it was diluted to volume and shaken well. The solution was nebulized and introduced into an inductively coupled plasma mass spectrometer (ICP-MS) to determine the yttrium content. Finally, a working curve was plotted using yttrium standard solutions with concentration gradients. The intensity ratio of the analyte to the internal standard reference line in the calibration curve solution was measured in ascending order. The calibration curve was plotted with the concentration of the analyte on the x-axis and the intensity ratio of the analyte to the internal standard reference line on the y-axis, and the concentration of yttrium in the steel was output.

[0022] 3. Reagents and Materials

[0023] 3.1 Hydrochloric acid, ρ approx. 1.19 g / mL (analytical grade);

[0024] 3.2 Nitric acid, ρ approx. 1.42 g / mL (analytical grade);

[0025] 3.3 Yttrium standard solution, 1000 μg / mL, should be serially diluted to 10 μg / mL before use;

[0026] 3.4 Internal standard solution: Cesium standard solution (1000 μg / mL), diluted to 10 μg / mL for use, sealed and protected from light, shelf life 6 months;

[0027] 3.5 Deionized water, resistivity ≥18.2MΩ・cm (to reduce blank interference).

[0028] 4. Main instruments and testing conditions

[0029] 4.1 ELAN DRC-e ICP-MS (PE Corporation, USA).

[0030] 4.2 Instrument parameters:

[0031] Power 1100 W; Plasma gas flow rate 15 L / min; Auxiliary gas flow rate 1.2 L / min; Carrier gas flow rate 0.85 L / min; Injection speed 1.5; Lens voltage 6.25; Sampling cone φ1.1; Truncation cone φ0.9; Scanning mode: peak skipping; Number of repetitions: 2.

[0032] 4.3 Analyte element Yttrium (89); internal standard element Cesium (140).

[0033] 5. Analysis Steps

[0034] 5.1 Sample Quantity

[0035] Weigh 0.1000 g of the steel shavings sample, accurate to 0.0002 g.

[0036] 5.2 Measurement Procedure

[0037] The weighed steel sample was placed in a 100 mL steel volumetric flask, and 15 mL of hydrochloric acid-nitric acid-water (volume ratio: 1:1:3) was added. The flask was heated on a 250℃ hot plate until the sample was completely dissolved. After cooling, the solution was diluted with deionized water and shaken well. The solution was then analyzed using a plasma mass spectrometer.

[0038] 5.3 Drawing Curves

[0039] Add equal amounts of mixed acid to five 100 mL volumetric flasks, then dilute the yttrium standard solution into the volumetric flasks as needed, make up to volume, and shake well. Plot the working curve based on the corresponding yttrium content values.

[0040] 6 Results and Discussion

[0041] 6.1 Accuracy Experiment

[0042] Weigh the steel sample and perform a spiked recovery test according to this method. The results are shown in Table 1:

[0043] Table 1. Accuracy of Measurement Results (%)

[0044]

[0045] The data in the table show that the recovery rate of the spiked experiment was between 95% and 110%, which proves that the accuracy of this analytical method is high.

[0046] 6.2 Precision Experiment

[0047] Eleven yttrium-containing steel samples were weighed and subjected to precision testing according to the above experimental method. The test results are shown in Table 2.

[0048] Table 2 Precision of Measurement Results (%)

[0049]

[0050] The above data indicates that the detection method has good precision.

[0051] 7. Conclusion

[0052] This method can accurately determine the yttrium content in low- and medium-alloy steels. The method is simple to operate, easy to master, and can meet production needs.

[0053] The following comparison of the present invention with two patents from the background art is illustrated below:

[0054] This statement provides a comprehensive comparison between this application (a method for detecting yttrium content in low-alloy steel) and two comparative examples (Comparative Example 1: a method for determining silicon, manganese, and titanium content in ferrophosphorus by ICP-AES; Comparative Example 2: a method for determining low-content titanium, molybdenum, and tungsten in stainless steel).

[0055] The detection object, matrix environment, and core technical solution of this application are fundamentally different from the two comparative examples. The specific differences are reflected in six core aspects: detection object, matrix adaptation, digestion system, detection instruments and parameters, internal standard selection, and operation procedure. A detailed comparison is shown in the table below and in the specific explanation:

[0056]

[0057] 1. The essential difference between Comparative Example 1 and this application: Comparative Example 1 detects silicon, manganese, and titanium in ferrophosphorus, uses an ICP-AES instrument, requires high-temperature treatment of the digestion system and residue treatment, and has no internal standard, its core solution being the efficiency problem of "simultaneous detection of multiple elements"; This application detects yttrium in medium and low alloy steel, uses an ICP-MS instrument, integrates digestion, and uses a single internal standard, its core solution being the method and efficiency problem of "specific detection of yttrium in medium and low alloy steel matrix". The two are completely different in terms of detection objects, matrix, instruments, and core technical routes.

[0058] 2. The essential difference between Comparative Example 2 and this application: Comparative Example 2 detects titanium, molybdenum, and tungsten in stainless steel, with a high-chromium-nickel stainless steel matrix (stronger interference). Its digestion system is designed for each element, and its internal standard system is complex, primarily addressing the interference problem of "detecting multiple low-content elements in stainless steel". This application, on the other hand, detects yttrium (a specific element) in medium- and low-alloy steel. The matrix interference types are different, and it adopts a single digestion system, a single internal standard, and integrated operation, primarily addressing the industry pain point of "no specific detection method for yttrium in medium- and low-alloy steel". The two applications differ significantly in matrix compatibility, element specificity, and operational complexity.

[0059] II. Technical Effects Arising from the Differences Between This Application and the Comparative Example

[0060] Filling an industry gap: Currently, there is no dedicated testing method for yttrium in medium and low alloy steels in the metallurgical industry. Comparative Examples 1 and 2 do not involve the detection of yttrium. This application is specifically designed to fill this gap and can be directly applied to the production testing of yttrium-containing medium and low alloy steels in fields such as construction, marine, and automobiles, thus meeting industrialization needs.

[0061] This application differs fundamentally from Comparative Examples 1 and 2 in terms of the detection object, matrix adaptation, digestion system, detection instrument, internal standard selection, and operation procedure. These differences bring about technical effects that the comparative examples cannot achieve (accurate detection of low content, high stability, high efficiency, environmental protection and safety, etc.), effectively solving the industry pain points of yttrium element detection in medium and low alloy steel.

[0062] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for determining yttrium in medium and low alloy steel, characterized in that: include: Weigh 0.1000g of steel shavings and place the sample in a 100mL volumetric flask. Add 20mL of a mixture of hydrochloric acid and nitric acid, heat at low temperature until the sample is completely dissolved, cool to room temperature, add water to make up to volume and shake well to obtain the test solution. Introduce the solution into an inductively coupled plasma mass spectrometer (ICP-MS) and determine the yttrium content using ICP-MS. Finally, plot a working curve using yttrium standard solutions with concentration gradients. Measure the intensity ratio of the analyte to the internal standard reference line in the working curve solution from low to high. Plot a calibration curve with the concentration of the analyte on the x-axis and the intensity ratio of the analyte to the internal standard reference line on the y-axis, and output the concentration of yttrium in the steel.

2. The method for determining yttrium in medium and low alloy steel according to claim 1, characterized in that: Weigh the steel sample to an accuracy of 0.0002g.

3. The method for determining yttrium in medium and low alloy steel according to claim 1, characterized in that: The volume ratio of the mixed acids is: hydrochloric acid + nitric acid + water = 1 + 1 + 3.

4. The method for determining yttrium in medium and low alloy steel according to claim 1, characterized in that: The temperature for the low-temperature heating is 240-260℃.

5. The method for determining yttrium in medium and low alloy steel according to claim 1 or 4, characterized in that: The low-temperature heating time is 15-30 minutes.

6. The method for determining yttrium in medium and low alloy steel according to claim 1, characterized in that: The low-temperature heating temperature is 250°C, and the low-temperature heating time is 20 minutes.

7. The method for determining yttrium in medium and low alloy steel according to claim 1, characterized in that: Curve plotting: Add equal amounts of mixed acid to five 100 mL volumetric flasks, then dilute the yttrium standard solution stepwise into the volumetric flasks as needed, make up to volume and shake well, and plot the working curve based on the corresponding yttrium content values.

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