Method for detecting content of trace cerium element in low alloy steel

Abstract

The invention discloses a method for detecting the content of trace cerium element in low alloy steel. The method comprises the following steps: respectively preparing a blank sample dissolved with a high-purity iron sample and a to-be-detected sample dissolved with a low alloy steel-containing sample; the method comprises the following steps: after selecting a cerium element standard mother solution, preparing a cerium element standard solution with gradient concentration by adopting a blank sample dissolved with a high-purity iron sample; and introducing the standard solution into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve, detecting the to-be-detected sample dissolved with the low-alloy-steel-containing sample under the same condition, and calculating the content of the cerium element in the to-be-detected sample dissolved with the low-alloy-steel-containing sample according to the standard curve. The method for measuring the trace cerium element in the low alloy steel through ICP is established for the first time, the method has the advantages of being high in sensitivity, good in stability, accurate in quantification, short in detection time, low in cost and the like, and a reliable detection method is provided for rapidly, efficiently and accurately measuring the content of the cerium element in the low alloy steel.

Description

Technical Field

[0001] The invention relates to the technical field of materials and metallurgy, and more specifically, to a method for detecting the content of trace cerium elements in low alloy steel. Background Art

[0002] Cerium (Ce) is the main element of rare earth elements in low alloy steel. Among them, the change of Ce content has an important influence on the performance of low alloy steel. Rare earth element cerium has an important influence on the performance of steel. Adding Ce to steel can play a role in desulfurization and deoxidation. It can 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. However, it is difficult to add rare earth element Ce to steel, and there are relatively few detection methods for low content of single element in rare earth, so it is very important to accurately determine the Ce content in low alloy steel.

[0003] The Chinese patent application number 202210859217.2 discloses a method for determining the cerium content in steel by spark source atomic emission spectrometry, comprising the following steps: (1) according to the estimated cerium content of the spectral sample to be tested, find at least 5 spectral standard samples with appropriate cerium content; (2) using sample preparation equipment to prepare the standard sample and the sample to be tested into a qualified analytical sample; (3) exciting the prepared 5-point standard sample in a spark source atomic emission spectrometer to obtain the corresponding 5 intensities, and establishing a corresponding relationship between the intensity and the cerium content in the standard sample to obtain a calibration working curve of cerium elements; (4) using the established calibration working curve to detect the cerium elements in the steel sample to be tested, and obtain the cerium and cerium content of the steel sample to be tested. However, this patent is for block samples, has poor detection flexibility, and only targets surface detection, and has poor representativeness. Chinese literature discloses "ICP-AES method for determination of cerium in steel", but the cerium content detected is in the range of 0.005% to 0.01%. At the same time, hydrochloric acid, nitric acid and citric acid are added during the sample dissolution process, and many reagents are used. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a method for detecting the trace cerium content in low alloy steel. By optimizing the detection parameters, a rapid and accurate quantitative analysis of the cerium element is achieved. At the same time, the method has the advantages of high sensitivity, good stability, accurate quantification, short detection time and low cost.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A method for detecting the content of trace cerium in low alloy steel, the method comprising the following steps:

[0007] (1) preparing a blank sample containing a high-purity iron sample and a test sample containing a low-alloy steel sample;

[0008] (2) After selecting the cerium element standard mother solution, a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L is prepared using the blank sample dissolved with the high-purity iron sample;

[0009] (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve, and the test sample dissolved with the low-alloy steel sample is detected under the same conditions, and the content of cerium in the test sample dissolved with the low-alloy steel sample is calculated according to the standard curve.

[0010] Optionally, the detection conditions of ICP in step (3) are as follows: the nebulizer gas flow rate is 0.5L / min~0.7L / min, preferably 0.60L / min; the plasma RF power is 1300W~1400W, preferably 1350W; the nebulizer flow rate is 0.5L / min~0.65L / min, preferably 0.60L / min; the auxiliary gas flow rate is 0.4L / min~0.55L / min, preferably 0.50L / min; the peristaltic pump speed is 55rpm~65rpm, preferably 60rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s~15s, preferably 10s; the short wave integration time is 10s~15s, preferably 10s.

[0011] Optionally, step (3) is calculated according to the following formula:

[0012]

[0013] Among them, ω m : The content of cerium in the sample, %; ρ m : Ce concentration, μg / ml; ω m0 : The content of cerium in pure iron, %; m: sample weight, g; V: solution volume, ml.

[0014] Optionally, in the step (2), the preparation of the standard solution of cerium element specifically includes the following steps: aspirating 10 mL of a cerium standard solution with a concentration of 1000 μg / mL and then diluting the volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL, respectively; aspirating 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL, respectively, and adding them to a volumetric flask for dissolving a sample containing high-purity iron, and preparing cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L, respectively, after diluting the volume.

[0015] Optionally, in step (1), the preparation of the test sample dissolved with the low alloy steel sample specifically includes the following steps: mixing the low alloy steel sample and nitric acid and digesting them under conditions of 280°C to 360°C to obtain the test sample dissolved with the low alloy steel sample.

[0016] Optionally, in step (1), the preparation of the blank sample in which the high-purity iron sample is dissolved specifically includes the following steps: dissolving the high-purity iron in nitric acid and diluting it with deionized water to obtain the iron matrix solution; the mass volume ratio of the high-purity iron to the nitric acid is 1g:(40ml~100ml).

[0017] The present invention also discloses a method for detecting the content of trace cerium in low alloy steel, the method comprising the following steps:

[0018] (1) preparing a sample to be tested in which a low alloy steel sample is dissolved: mixing the low alloy steel sample and nitric acid for digestion, adding ammonia water to the digested solution to form a precipitate, and filtering to obtain the sample to be tested in which the low alloy steel sample is dissolved;

[0019] (2) After selecting the cerium element standard mother solution, a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L is prepared;

[0020] (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve, and the test sample dissolved with the low-alloy steel sample is detected under the same conditions, and the content of cerium in the test sample dissolved with the low-alloy steel sample is calculated according to the standard curve.

[0021] Optionally, the detection conditions of ICP in step (3) are as follows: the nebulizer gas flow rate is 0.5L / min~0.7L / min, preferably 0.60L / min; the plasma RF power is 1300W~1400W, preferably 1350W; the nebulizer flow rate is 0.5L / min~0.65L / min, preferably 0.60L / min; the auxiliary gas flow rate is 0.4L / min~0.55L / min, preferably 0.50L / min; the peristaltic pump speed is 55rpm~65rpm, preferably 60rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s~15s, preferably 10s; the short wave integration time is 10s~15s, preferably 10s.

[0022] Optionally, step (3) is calculated according to the following formula:

[0023]

[0024] Among them, ω m : The content of cerium in the sample, %; ρ m : concentration of cerium, μg / ml; m: sample weight, g; V: solution volume, ml.

[0025] Optionally, in the step (2), the preparation of the standard solution of cerium element specifically includes the following steps: aspirating 10 mL of a cerium standard solution with a concentration of 1000 μg / mL and then diluting the volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL, respectively; aspirating 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL, respectively, and then diluting the volume to prepare cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L, respectively.

[0026] Optionally, in step (1), the digestion temperature is 280°C to 360°C.

[0027] Implementing the embodiments of the present invention will have the following beneficial effects:

[0028] (1) The present invention uses an inductively coupled plasma emission spectrometry method to determine the content of trace rare earth element cerium in low alloy steel. The method is simple, rapid, accurate, and has low detection cost.

[0029] (2) The present invention optimizes the digestion method and adopts the (1+2) nitric acid digestion and dissolution method, which can quickly dissolve the sample completely, and at the same time effectively reduce the interference of the sample matrix and impurity components on the ICP determination process, so that the extracted sample can meet the subsequent analysis requirements; and the present application only uses nitric acid to dissolve the sample, increase the sample weight, reduce background interference, remove iron elements when necessary, and reduce element interference, so as to realize the detection of trace cerium elements in low-alloy steel, and provide an accurate data basis for on-site personnel to understand the trace cerium elements.

[0030] (3) The detection method of the present invention is easy for other laboratory personnel to learn; the detection of drugs is routine and easy for other laboratories to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a relationship diagram between the sample weight of the cerium element and the relative standard deviation in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific embodiments, but the present invention is not limited in any way.

[0033] The invention discloses a method for detecting the content of trace cerium in low alloy steel, the method comprising the following steps:

[0034] (1) Prepare a blank sample containing a high-purity iron sample and a test sample containing a low-alloy steel sample.

[0035] In a specific embodiment, the preparation of a blank sample containing a high-purity iron sample comprises the following steps: dissolving high-purity iron in nitric acid and diluting with deionized water to obtain an iron matrix solution; the mass volume ratio of high-purity iron to nitric acid is 1g:(40ml~100ml).

[0036] In a specific embodiment, the preparation of the test sample in which the low alloy steel sample is dissolved specifically includes: mixing the low alloy steel sample and nitric acid (1+2) and digesting them at 280°C to 360°C to obtain the test sample in which the low alloy steel sample is dissolved.

[0037] (2) After selecting the cerium element standard mother solution, a blank sample dissolved with a high-purity iron sample is used to prepare a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L.

[0038] In a specific embodiment, the preparation of the standard solution of cerium element specifically includes the following steps: aspirating 10 mL of a cerium standard solution with a concentration of 1000 μg / mL and then diluting the volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL, respectively; aspirating 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL, respectively, and adding them to a volumetric flask for dissolving a sample containing high-purity iron, and preparing cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L, and 0.010 g / L, respectively, after diluting the volume.

[0039] (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve. The test sample containing the low alloy steel sample is detected under the same conditions, and the content of cerium in the test sample containing the low alloy steel sample is calculated according to the standard curve.

[0040] In a specific embodiment, the detection conditions of ICP in step (3) are as follows: the nebulizer gas flow rate is 0.5L / min to 0.7L / min; the plasma radio frequency power is 1300W to 1400W; the nebulizer flow rate is 0.5L / min to 0.65L / min; the auxiliary gas flow rate is 0.4L / min to 0.55L / min; the peristaltic pump speed is 55rpm to 65rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s to 15s; the short wave integration time is 10s to 15s. Preferably, the detection conditions of ICP are as follows: the nebulizer gas flow rate is 0.60L / min; the plasma radio frequency power is 1350W; the nebulizer flow rate is 0.60L / min; the auxiliary gas flow rate is 0.50L / min; the peristaltic pump speed is 60rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s; the short wave integration time is 10s.

[0041] In one specific embodiment, the specific calculation is based on the following formula:

[0042]

[0043] Among them, ω m : The content of cerium in the sample, %; ρ m : Ce concentration, μg / ml; ω m0 : The content of cerium in pure iron, %; m: sample weight, g; V: solution volume, ml.

[0044] The present invention also discloses a method for detecting the content of trace cerium in low alloy steel, the method comprising the following steps:

[0045] (1) Preparing a test sample containing a low alloy steel sample dissolved therein: mixing the low alloy steel sample and nitric acid for digestion, adding ammonia water to the digested solution to form a precipitate, and filtering to obtain a test sample containing a low alloy steel sample dissolved therein.

[0046] In a specific embodiment, the digestion temperature is 280°C to 360°C.

[0047] (2) After selecting the standard cerium element mother solution, a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L was prepared.

[0048] In a specific embodiment, the preparation of the standard solution of cerium element specifically includes the following steps: 10 mL of a cerium standard solution with a concentration of 1000 μg / mL is drawn and then fixed to volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL, respectively; 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL are drawn respectively, and then fixed to volume to prepare cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L, respectively.

[0049] (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve. The test sample containing the low alloy steel sample is detected under the same conditions, and the content of cerium in the test sample containing the low alloy steel sample is calculated according to the standard curve.

[0050] In a specific embodiment, the detection conditions of ICP in step (3) are as follows: the nebulizer gas flow rate is 0.5L / min-0.7L / min; the plasma RF power is 1300W-1400W; the nebulizer flow rate is 0.5L / min-0.65L / min; the auxiliary gas flow rate is 0.4L / min-0.55L / min; the peristaltic pump speed is 55rpm-65rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s-15s; the short wave integration time is 10s-15s. Preferably, the detection conditions of ICP are as follows: the nebulizer gas flow rate is 0.60L / min; the plasma RF power is 1350W; the nebulizer flow rate is 0.60L / min; the auxiliary gas flow rate is 0.50L / min; the peristaltic pump speed is 60rpm; the vertical observation height is 12.0mm; the long wave integration time is 10s; the short wave integration time is 10s.

[0051] In a specific embodiment, step (3) is calculated according to the following formula:

[0052]

[0053] Among them, ω m : The content of cerium in the sample, %; ρ m : concentration of cerium, μg / ml; m: sample weight, g; V: solution volume, ml.

[0054] The following are specific embodiments

[0055] Example 1

[0056] 1. Experimental instruments and reagents

[0057] The test instrument used is ICP.

[0058] Cerium standard solution: 1000μg / mL, national standard solution.

[0059] 2. Experimental steps

[0060] 2.1 Solution preparation

[0061] 2.1.1 Prepare a blank sample containing high purity iron sample:

[0062] 0.2 g of high-purity iron (99.98%) was dissolved in 20 ml of nitric acid (1+2), and diluted with deionized water to obtain a blank sample in which the high-purity iron sample was dissolved.

[0063] 2.1.2 Preparation of standard solution:

[0064] 10 mL of 1000 μg / mL cerium standard solution was pipetted and fixed to volume to obtain a 0.25 μg / mL cerium standard solution and a 2.5 μg / mL cerium standard solution respectively; 2 mL, 4 mL and 8 mL of 0.25 μg / mL cerium standard mother solution and 4 mL and 8 mL of 2.5 μg / mL cerium standard mother solution were respectively pipetted and added into volumetric flasks for dissolving samples containing high-purity iron, and after fixed to volume, standard cerium solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L were prepared respectively.

[0065] 2.1.3 Prepare the test sample containing dissolved low alloy steel sample:

[0066] Accurately weigh 0.2g of low alloy steel sample, place the sample in a 100ml two-purpose bottle, add 20ml nitric acid (1+2) on an electric furnace, slowly heat to 320℃ until completely dissolved, and adjust the volume to obtain a test sample containing the dissolved low alloy steel sample.

[0067] 2.2 Testing conditions:

[0068] Turn on the ICP and run it for at least 1 hour before measuring. Adjust the parameters according to the working conditions in Table 1, and set the number of cleaning runs to once and the number of measurements to four. Take the average value of multiple measurements to reduce the system error.

[0069] Example 2

[0070] 1. Experimental instruments and reagents

[0071] The test instrument used is ICP.

[0072] Cerium standard solution: 1000μg / mL, national standard solution.

[0073] 2. Experimental steps

[0074] 2.1 Solution preparation

[0075] 2.1.1 Preparation of standard solution:

[0076] 10 mL of 1000 μg / mL cerium standard solution was pipetted and fixed to volume to obtain a 0.25 μg / mL cerium standard solution and a 2.5 μg / mL cerium standard solution respectively; 2 mL, 4 mL and 8 mL of 0.25 μg / mL cerium standard mother solution and 4 mL and 8 mL of 2.5 μg / mL cerium standard mother solution were respectively pipetted and fixed to volume to prepare cerium element standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L respectively.

[0077] 2.1.3 Prepare the test sample containing dissolved low alloy steel sample:

[0078] Accurately weigh 0.2g of low alloy steel sample, place the sample in a 100ml two-purpose bottle, add 20ml nitric acid (1+2) on an electric furnace, slowly heat to 320℃ until completely dissolved, and add 0.91g / ml ammonia water to the digested solution to form a precipitate to obtain a test sample containing the low alloy steel sample dissolved therein.

[0079] 2.2 Testing conditions:

[0080] Turn on the ICP and run it for at least 1 hour before measuring. Adjust the parameters according to the working conditions in Table 1, and set the number of cleaning runs to once and the number of measurements to four. Take the average value of multiple measurements to reduce the system error.

[0081] Table 1 ICP working conditions

[0082]

[0083] 2.3 Methodological investigation

[0084] 2.3.1 Investigation of linear relationship

[0085] A series of standard solutions with concentration gradients were measured under the above conditions, and the peak area-concentration standard curve was drawn and linear regression was performed to obtain the regression equation of the cerium element standard curve, as shown in Table 2. It has a good linear relationship and the correlation coefficient R 2 Greater than 0.99, with a wide linear range, which can meet the detection requirements.

[0086] Table 2 Results of investigation on the linear relationship of cerium element

[0087]

[0088] 2.3.2 Short-term stability study

[0089] Weigh 0.1g, 0.2g, 0.3g, and 0.4g of low alloy steel samples for comparison. Repeat the test 8 times under the above conditions. The test results are as follows: Figure 1 As shown in Table 3, as the sample weight increases, the stability of the test results increases. Considering the dissolution of the sample, a sample weight of 0.2 g can meet the stability requirements of the test.

[0090] Table 3 Results of stability study of cerium element

[0091]

[0092]

[0093] 2.3.3 Investigation of spike recovery

[0094] Take two identical samples to be tested containing low alloy steel sample dissolved therein, one of which is tested for cerium according to the above analysis steps, and the other is tested after adding a quantitative amount of standard substance of the tested component. The result of the spiked one is subtracted from the result of the unspiked one, and the ratio of the difference to the theoretical value of the added standard substance is the sample spike recovery rate. The results are shown in Table 4.

[0095] Table 4 Results of the recovery rate of spiked cerium

[0096]

[0097] According to the above results, the recovery rate of spiked samples ranged from 96% to 104%, which met the needs of analytical determination.

[0098] 2.3.4 Inspection of testing equipment

[0099] Inductively coupled plasma emission spectrometer and direct reading spectrometer were selected to detect 5 groups of samples 8 times respectively. The results are shown in Table 5.

[0100] Table 5 Results of the inspection of cerium element detection equipment

[0101]

[0102] According to the test results in Table 5, the test results of the direct reading spectrometer have a large fluctuation range and poor precision, while the test results of the inductively coupled plasma emission spectrometer have better precision and are more suitable for the detection of low-content elements.

[0103] In summary, the present invention establishes for the first time a method for ICP determination of trace cerium in low alloy steel, and realizes rapid and accurate quantitative analysis of cerium by optimizing the digestion method and detection parameters. The detection method of the present invention has the advantages of high sensitivity, good stability, accurate quantification, short detection time, low cost, etc., and provides a reliable detection method for rapid, efficient and accurate determination of the cerium content in low alloy steel.

[0104] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for detecting trace cerium content in low alloy steel, characterized in that: The method comprises the following steps: (1) preparing a blank sample containing a high-purity iron sample and a test sample containing a low-alloy steel sample; (2) After selecting the cerium element standard mother solution, a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L is prepared using the blank sample dissolved with the high-purity iron sample; (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve, and the test sample dissolved with the low-alloy steel sample is detected under the same conditions, and the content of cerium in the test sample dissolved with the low-alloy steel sample is calculated according to the standard curve.

2. The method for detecting trace cerium content in low alloy steel according to claim 1, characterized in that: The detection conditions of ICP in step (3) are as follows: nebulizer gas flow rate is 0.5L / min~0.7L / min; plasma RF power is 1300W~1400W; nebulizer flow rate is 0.5L / min~0.65L / min; auxiliary gas flow rate is 0.4L / min~0.55L / min; peristaltic pump speed: 55rpm~65rpm; vertical observation height: 12.0mm; long wave integration time: 10s~15s; short wave integration time: 10s~15s.

3. The method for detecting trace cerium content in low alloy steel according to claim 1, characterized in that: In step (3), the calculation is specifically based on the following formula: Among them, ω m : The content of cerium in the sample, %; ρ m : Ce concentration, μg / ml; ω m0 : The content of cerium in pure iron, %; m: sample weight, g; V: solution volume, ml.

4. The method for detecting trace cerium content in low alloy steel according to claim 1, characterized in that: In the step (2), the preparation of the cerium standard solution specifically includes the following steps: aspirating 10 mL of a cerium standard solution with a concentration of 1000 μg / mL and then diluting the volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL, respectively; aspirating 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL, respectively, and adding them to a volumetric flask for dissolving a sample containing high-purity iron, and diluting the volume to prepare cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L, respectively.

5. The method for detecting trace cerium content in low alloy steel according to claim 1, characterized in that: In the step (1), the preparation of the test sample containing the low alloy steel sample dissolved therein specifically comprises the following steps: mixing the low alloy steel sample and nitric acid and digesting them at 280° C. to 360° C. to obtain the test sample containing the low alloy steel sample dissolved therein; In the step (1), the preparation of the blank sample in which the high-purity iron sample is dissolved specifically includes the following steps: dissolving the high-purity iron in nitric acid and diluting it with deionized water to obtain the iron matrix solution; the mass volume ratio of the high-purity iron to the nitric acid is 1g:(40ml~100ml).

6. A method for detecting trace cerium content in low alloy steel, characterized in that: The method comprises the following steps: (1) preparing a sample to be tested in which a low alloy steel sample is dissolved: mixing the low alloy steel sample and nitric acid for digestion, adding ammonia water to the digested solution to form a precipitate, and filtering to obtain the sample to be tested in which the low alloy steel sample is dissolved; (2) After selecting the cerium element standard mother solution, a cerium element standard solution with a gradient concentration of 0.0 g / L to 0.010 g / L is prepared; (3) The standard solution is introduced into an inductively coupled plasma emission spectrometer for measurement to obtain a standard curve, and the test sample dissolved with the low-alloy steel sample is detected under the same conditions, and the content of cerium in the test sample dissolved with the low-alloy steel sample is calculated according to the standard curve.

7. The method for detecting trace cerium content in low alloy steel according to claim 6, characterized in that: The detection conditions of ICP in step (3) are as follows: nebulizer gas flow rate is 0.5L / min-0.7L / min; plasma RF power is 1300W~1400W; nebulizer flow rate is 0.5L / min~0.65L / min; auxiliary gas flow rate is 0.4L / min~0.55L / min; peristaltic pump speed: 55rpm~65rpm; vertical observation height: 12.0mm; long wave integration time: 10s~15s; short wave integration time: 10s-15s.

8. The method for detecting trace cerium content in low alloy steel according to claim 6, characterized in that: In step (3), the calculation is specifically based on the following formula: Among them, ω m : The content of cerium in the sample, %; ρ m : concentration of cerium, μg / ml; m: sample weight, g; V: solution volume, ml.

9. The method for detecting trace cerium content in low alloy steel according to claim 6, characterized in that: In the step (2), the preparation of the cerium standard solution specifically includes the following steps: 10 mL of a cerium standard solution with a concentration of 1000 μg / mL is drawn and fixed to volume to obtain a cerium standard solution with a concentration of 0.25 μg / mL and a cerium standard solution with a concentration of 2.5 μg / mL respectively; 2 mL, 4 mL and 8 mL of a cerium standard mother solution with a concentration of 0.25 μg / mL and 4 mL and 8 mL of a cerium standard mother solution with a concentration of 2.5 μg / mL are drawn respectively, and after fixing to volume, cerium standard solutions with cerium concentrations of 0 g / L, 0.0005 g / L, 0.001 g / L, 0.003 g / L, 0.005 g / L, 0.008 g / L and 0.010 g / L are prepared.

10. The method for detecting trace cerium content in low alloy steel according to claim 6, characterized in that: In the step (1), the digestion temperature is 280°C to 360°C.

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