A method for detecting carbon and sulfur content in metallic chromium

Abstract

The invention discloses a method for detecting the carbon and sulfur content in metallic chromium, comprising: weighing pure iron flux, tungsten flux and a standard metallic chromium sample and placing them in a ceramic crucible; making the pure iron flux, tungsten flux and the standard metallic chromium sample evenly distributed; placing the ceramic crucible on an infrared carbon-sulfur analyzer and starting analysis and detection; using the carbon and sulfur contents of the standard metallic chromium sample obtained by detection to draw a calibration curve of the infrared carbon-sulfur analyzer; taking pure iron flux, the metallic chromium sample to be tested, tin flux and tungsten flux and placing them in a ceramic crucible and mixing them evenly; using an infrared carbon-sulfur analyzer to analyze and detect the metallic chromium sample to be tested, and combining the obtained calibration curve of the infrared carbon-sulfur analyzer to obtain the carbon and sulfur contents in the metallic chromium sample to be tested. The carbon and sulfur content data of metallic chromium measured by the invention are more stable and accurate, and the analysis speed is fast and the time required is short. The invention only uses a small amount of chemical reagents and has the advantages of energy saving and environmental protection.

Description

Technical Field

[0001] The invention belongs to the technical field of metal detection, and more specifically, relates to a method for detecting carbon and sulfur content in metallic chromium. Background Art

[0002] As impurity elements, sulfur and carbon often exist in metals in the form of non-metallic compounds, forming non-metallic impurities, which lead to the deterioration of material properties. In particular, the presence of sulfur causes the hot brittleness of the material. The sulfur content is an important element to be controlled in metallic chromium, and its content is one of the important indicators for evaluating the quality of metallic chromium.

[0003] At present, the volumetric method and the gravimetric method are used for detection. The commonly used volumetric methods include gas volumetric method and non-aqueous titration method for carbon measurement, iodine titration method and acid-base titration method for sulfur measurement, but these methods are not accurate enough; the gravimetric method often uses alkaline asbestos to absorb carbon dioxide, and the carbon content is calculated from the increment. The determination of sulfur content usually uses wet sample to decompose and oxidize with acid to convert it into sulfate, and then add barium chloride in hydrochloric acid medium to generate barium sulfate. After precipitation, filtration, washing, burning, weighing, the sulfur content is finally calculated. The disadvantage of the gravimetric method is that the analysis speed is slow and the results cannot be obtained quickly.

[0004] The infrared carbon and sulfur analyzer has the advantages of high automation, fast analysis speed and high accuracy of test results. However, if the instrument is used for analysis, the test data may be unstable due to differences in the instrument, sample size and sample weight. Therefore, it is necessary to reduce the impact of various factors on data stability and improve data stability and credibility. Summary of the invention

[0005] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0006] In order to achieve these purposes and other advantages according to the present invention, a method for detecting carbon and sulfur content in metallic chromium is provided, comprising the following steps:

[0007] Step 1, weigh pure iron flux, tungsten flux, tin flux and standard metal chromium sample and place them in a ceramic crucible;

[0008] Step 2: Gently shake the ceramic crucible to evenly distribute the pure iron flux, tungsten flux, tin flux and standard metal chromium sample;

[0009] Step 3: Place the ceramic crucible on the infrared carbon and sulfur analyzer and start analysis and detection;

[0010] Step 4: Using the carbon and sulfur contents of the standard metal chromium sample obtained by detection, a calibration curve of the infrared carbon and sulfur analyzer is drawn;

[0011] Step 5, weigh pure iron flux, the metal chromium sample to be tested, tin flux, and tungsten flux in sequence, place them in a ceramic crucible and mix them evenly;

[0012] Step 6: Analyze and detect the metal chromium sample to be tested using an infrared carbon-sulfur analyzer, and combine the calibration curve of the infrared carbon-sulfur analyzer obtained in step 4 to obtain the carbon and sulfur contents in the metal chromium sample to be tested.

[0013] Preferably, in step three and step five, the infrared carbon-sulfur analyzer used is a HCS-808 high-frequency infrared carbon-sulfur analyzer.

[0014] Preferably, in the steps 1 and 5, the iron content of the pure iron flux used is greater than 99.8%, C is less than 0.0005%, S is less than 0.0005%, and the particle size is less than 1.25 mm.

[0015] Preferably, in step 1, the standard metal chromium sample has a carbon content of 0.087% and a sulfur content of 0.0053%.

[0016] Preferably, in the step 1 and the step 5, the tungsten flux used is tungsten granules, W ≥ 99.5%, S < 0.0008%, C < 0.0005% in the tungsten granules, and the particle size of the tungsten granules is 0.4-0.8 mm.

[0017] Preferably, in the step 1 and the step 5, the tin flux used is tin particles, and the S in the tin particles is less than 0.0008%, the C is less than 0.0005%, and the particle size is 0.4-0.8 mm.

[0018] Preferably, in step 1, the mass ratio of pure iron flux, tungsten flux, tin flux and standard metal chromium sample is 3:2 to 3:2 to 3:15.

[0019] Preferably, in step five, the mass ratio of pure iron flux, the metal chromium sample to be tested, tin flux and tungsten flux is 3:2:3:15.

[0020] Preferably, the amount of the metal chromium sample to be tested in step five is less than the amount of the standard metal chromium sample in step one.

[0021] Preferably, when the HCS-808 high-frequency infrared carbon-sulfur analyzer detects the carbon and sulfur contents of the standard metallic chromium sample and the metallic chromium sample to be tested, the working parameters are set as follows: the first-level gas pressure of the oxygen and nitrogen supply is above 2Mpa, and the second-level gauge pressure of the pressure reducing valve is adjusted to 0.5MPa; ensure that the gas path is normal, the analysis pressure gauge on the HCS-808 high-frequency infrared carbon-sulfur analyzer is 0.08MPa, the top oxygen pressure is 0.15Mpa, the top oxygen rotor flowmeter is 2L / min, and the analysis rotor flowmeter is 3.5L / min; the waveforms of carbon and sulfur are stable, the entire curve is in a parallel trend, the difference between the peak and the trough of the entire waveform is less than 0.003, and the initial voltage of carbon and sulfur is between 0.5 and 1.5V.

[0022] In order to further shorten the detection and analysis time of the carbon and sulfur content of the metal chromium to be tested by the HCS-808 high-frequency infrared carbon and sulfur analyzer, before the carbon and sulfur content of the metal chromium to be tested is detected, the pure iron flux, tungsten flux and tin flux are first refined to obtain a mixed flux, and the pure iron flux, tungsten flux and tin flux are pre-mixed, and the particle size of the pure iron flux, tungsten flux and tin flux is refined within a narrower range, and the uniformity of the mixing of the three fluxes and the uniformity of the particle size distribution are improved, the fluxing effect of each flux is improved, the melting time of the metal chromium and the analysis time of the infrared carbon and sulfur analyzer are shortened, and the stability of the carbon and sulfur content detection is improved; wherein, the specific method of refining the pure iron flux, tungsten flux and tin flux to obtain the mixed flux includes:

[0023] S1. Pure iron flux, tin flux and tungsten flux are mixed in a mass ratio of 3:3:15 to obtain a mixed powder; the mixed powder is ball-milled, silicon nitride is used as a grinding ball, the mass ratio of the grinding ball to the mixed powder is 2-4:1, anhydrous ethanol is used as a ball-milling medium, the amount of anhydrous ethanol is 40% of the volume of the ball mill, and the ball mill is evacuated to 1.5×10 -5 Pa, set the ball milling speed to 800-1200 rpm, and the ball milling time to 3-12 h; after ball milling, separate the mixed powder and perform vacuum drying at a drying temperature of 100-120 ° C and a drying time of 30-50 min;

[0024] S2. The dried mixed powder is subjected to vacuum sintering, and the vacuum degree is less than 2.1×10 -6 Pa, sintering temperature is 500-800°C, sintering heating rate is 5-10°C / min, holding time is 5-20min; cooling down to room temperature at a cooling rate of 5-10°C to obtain sintered mixed powder;

[0025] S3, dry ball milling the sintered mixed powder, using stainless steel grinding balls, the mass ratio of stainless steel grinding balls to mixed powder is 4:1, and the vacuum degree of ball milling is less than 4.0×10-6 Pa, the ball milling speed is 400-800 rpm, and the ball milling time is 4-6 h to obtain a mixed flux.

[0026] The present invention has at least the following beneficial effects: the carbon and sulfur content data of the metal chromium sample measured by the present invention are more stable and accurate, and the analysis speed is fast and the time required is short. The present invention is energy-saving and environmentally friendly; the use of volumetric method, gravimetric method and other analysis methods requires the use of more organic reagents, which are highly toxic, harmful to operators, and cause great environmental pollution, while the present invention only uses a small amount of chemical reagents, which has the advantages of energy saving and environmental protection.

[0027] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0028] The present invention is described in further detail below so that those skilled in the art can implement it according to the description.

[0029] It should be understood that terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0030] Ensure the supply of oxygen and nitrogen, the first-level air pressure is above 2Mpa, and adjust the second-level gauge pressure of the pressure reducing valve to 0.5MPa; ensure that the gas circuit is normal, the analytical pressure gauge on the instrument is 0.08MPa, the top oxygen pressure is 0.15Mpa, the top oxygen rotor flowmeter is 2L / min, and the analytical rotor flowmeter is 3.5L / min; the waveforms of carbon and sulfur are stable, the entire curve is in a parallel trend, the difference between the peak and the trough of the entire waveform is less than 0.003, and the initial voltage of carbon and sulfur should be between 0.5 and 1.5V.

[0031] The ceramic crucible used in each embodiment of the present invention needs to be treated at 1000° C. for 1 hour and then cooled before use.

[0032] Embodiment 1:

[0033] This embodiment provides a method for detecting carbon and sulfur content in metallic chromium, comprising the following steps:

[0034] Step 1, weigh 0.3g pure iron flux (iron content>99.8%, C<0.0005%, S<0.0005%, particle size<1.25mm), 0.2g standard metal chromium sample (carbon content of 0.087%, sulfur content of 0.0053%), 0.3g tin flux, 1.5g tungsten flux (S<0.0008%, C<0.0005% in tin particles, particle size of 0.4-0.8mm) in sequence and place them in a ceramic crucible;

[0035] Step 2: Gently shake the ceramic crucible to evenly distribute and mix the pure iron flux, tin flux, tungsten flux and standard metal chromium sample;

[0036] Step 3: Place the ceramic crucible on the HCS-808 high-frequency infrared carbon-sulfur analyzer and start analyzing and testing the standard metal chromium sample;

[0037] Step 4: Use the carbon and sulfur contents of the standard metal chromium sample obtained by the test to draw a calibration curve of the infrared carbon and sulfur analyzer; wherein, in this embodiment, the same standard metal chromium sample is selected for two tests, and the expression of the established carbon content calibration curve is y=kx, and the carbon and sulfur contents are calibrated respectively, and the certified mass output by the HCS-808 high-frequency infrared carbon and sulfur analyzer is used as x, and the adjusted area output is used as y, wherein the x and y values ​​of the two tests are shown in the following table:

[0038] x y Standard metal chromium sample 1 0.8751 0.9447 Standard metal chromium sample 2 0.9345 0.9683

[0039] The fitted carbon content calibration curve expression is: y=0..3973x, and the correlation coefficient is 0.3.

[0040] Similarly, the sulfur content is calibrated, and the two data are shown in the following table:

[0041] x y Standard metal chromium sample 1 0.8741 0.9943 Standard metal chromium sample 2 0.7992 0.9104

[0042] The calibration curve expression of sulfur content obtained by fitting is: y=1.1196x, and the correlation coefficient is 0.1.

[0043] Step 5, weigh 0.3g of pure iron flux, 0.2g of the metal chromium sample to be tested, 0.3g of tin flux, and 1.5g of tungsten flux in a ceramic crucible and mix them evenly;

[0044] Step 6: Analyze and detect the metal chromium sample to be tested using the HCS-808 high-frequency infrared carbon-sulfur analyzer, combine the carbon and sulfur calibration curves of the infrared carbon-sulfur analyzer obtained in step 4, obtain the mass of carbon and sulfur respectively through the output adjusted area, and then calculate the carbon and sulfur contents of the metal chromium sample to be tested, and obtain the carbon and sulfur contents in the metal chromium sample to be tested. In this embodiment, when the carbon content of the metal chromium sample to be tested is detected, the analysis time of the HCS-808 high-frequency infrared carbon-sulfur analyzer is 42s, and when the sulfur content of the metal chromium sample to be tested is detected, the analysis time is 43s.

[0045] Embodiment 2:

[0046] This embodiment provides a method for detecting carbon and sulfur content in metallic chromium, comprising the following steps:

[0047] Step 1: weigh 0.3g of pure iron flux, 0.3g of standard metal chromium sample, 1.5g of tungsten flux and 0.3g of tin flux in a ceramic crucible;

[0048] Step 2: Gently shake the ceramic crucible to evenly distribute the pure iron flux, tungsten flux and standard metal chromium sample;

[0049] Step 3: Place the ceramic crucible on the HCS-808 high-frequency infrared carbon-sulfur analyzer and start analyzing the standard metal chromium sample;

[0050] Step 4: Using the carbon and sulfur contents of the standard metal chromium sample obtained by detection, a calibration curve of the infrared carbon and sulfur analyzer is drawn;

[0051] Step 5, weigh 0.3g of pure iron flux, 0.2g of the metal chromium sample to be tested, 0.3g of tin flux, and 1.5g of tungsten flux in a ceramic crucible and mix them evenly;

[0052] Step 6: Analyze and detect the metal chromium sample to be tested using the HCS-808 high-frequency infrared carbon and sulfur analyzer, and combine the calibration curve of the infrared carbon and sulfur analyzer obtained in step 4 to obtain the carbon and sulfur contents in the metal chromium sample to be tested. In this embodiment, when the carbon content of the metal chromium sample to be tested is detected, the analysis time of the HCS-808 high-frequency infrared carbon and sulfur analyzer is 40s, and when the sulfur content of the metal chromium sample to be tested is detected, the analysis time is 43s.

[0053] Embodiment 3:

[0054] This embodiment provides a method for detecting carbon and sulfur content in metallic chromium, comprising the following steps:

[0055] Step 1: weigh 0.3g pure iron flux, 0.2g standard sample, 1.5g tungsten flux and 0.2g tin flux in sequence and place them in a ceramic crucible;

[0056] Step 2: Gently shake the ceramic crucible to evenly distribute the pure iron flux, tungsten flux and standard metal chromium sample;

[0057] Step 3: Place the ceramic crucible on the HCS-808 high-frequency infrared carbon-sulfur analyzer and start analyzing the standard metal chromium sample;

[0058] Step 4: Using the carbon and sulfur contents of the standard metal chromium sample obtained by detection, a calibration curve of the infrared carbon and sulfur analyzer is drawn;

[0059] Step 5, weigh 0.3g of pure iron flux, 0.3g of tin flux, 1.5g of tungsten flux in sequence, and finally weigh 0.2g of the metal chromium sample to be tested, place them in a ceramic crucible and mix them evenly;

[0060] Step 6: Analyze and detect the metal chromium sample to be tested using the HCS-808 high-frequency infrared carbon-sulfur analyzer, and obtain the carbon and sulfur contents in the metal chromium sample to be tested by combining the calibration curve of the infrared carbon-sulfur analyzer obtained in step 4. In this embodiment, when the carbon content of the metal chromium sample to be tested is detected, the analysis time of the HCS-808 high-frequency infrared carbon-sulfur analyzer is 41 seconds, and when the sulfur content of the metal chromium sample to be tested is detected, the analysis time is 44 seconds.

[0061] Embodiment 4:

[0062] This embodiment provides a method for detecting carbon and sulfur content in metallic chromium, comprising the following steps:

[0063] Step 1: weigh 0.3g pure iron flux, 0.3g standard metal chromium sample, 1.5g tungsten flux, and 0.2g tin flux in a ceramic crucible;

[0064] Step 2: Gently shake the ceramic crucible to evenly distribute the pure iron flux, tungsten flux and standard metal chromium sample;

[0065] Step 3: Place the ceramic crucible on the HCS-808 high-frequency infrared carbon-sulfur analyzer and start analyzing the standard metal chromium sample;

[0066] Step 4: Using the carbon and sulfur contents of the standard metal chromium sample obtained by detection, a calibration curve of the infrared carbon and sulfur analyzer is drawn;

[0067] Step 5: weigh 0.3g of pure iron flux, 0.3g of tin flux, and 1.5g of tungsten flux in sequence, and finally weigh 0.2g of the metal chromium sample to be tested, shake the ceramic crucible to evenly distribute the sample, and spread it in the ceramic crucible;

[0068] Step 6: Analyze and detect the metal chromium sample to be tested using the HCS-808 high-frequency infrared carbon-sulfur analyzer, and obtain the carbon and sulfur contents in the metal chromium sample to be tested by combining the calibration curve of the infrared carbon-sulfur analyzer obtained in step 4. In this embodiment, when the carbon content of the metal chromium sample to be tested is detected, the analysis time of the HCS-808 high-frequency infrared carbon-sulfur analyzer is 42 seconds, and when the sulfur content of the metal chromium sample to be tested is detected, the analysis time is 43 seconds.

[0069] Example 5

[0070] This embodiment provides a method for detecting the carbon and sulfur content in metallic chromium. The standard metallic chromium sample and the metallic chromium sample to be detected are the same as those in Example 1. The difference is that in step 5 of this embodiment, 2.1 g of mixed flux is used to replace 0.3 g of pure iron flux, 0.3 g of tin flux, and 1.5 g of tungsten flux in Example 1. The mass of the metallic chromium to be detected is the same, and the methods and parameters of the remaining steps are the same as those in Example 1. Among them, the analysis time of the HCS-808 high-frequency infrared carbon and sulfur analyzer in step 5 of this embodiment is 24 s.

[0071] The preparation method of the mixed flux used in this embodiment includes:

[0072] S1. Pure iron flux, tin flux and tungsten flux were mixed in a mass ratio of 3:3:15 to obtain a mixed powder; the mixed powder was ball-milled, silicon nitride was used as grinding balls, the mass ratio of grinding balls to mixed powder was 2:1, anhydrous ethanol was used as ball-milling medium, the amount of anhydrous ethanol was 40% of the volume of the ball mill, and the ball mill was evacuated to 1.2×10 -5 Pa, set the ball milling speed to 800 rpm, and the ball milling time to 6 h; after ball milling, separate the mixed powder and perform vacuum drying at a drying temperature of 110 °C and a drying time of 30 min;

[0073] S2: The dried mixed powder is subjected to vacuum sintering with a vacuum degree of 1.6×10 -6 Pa, sintering temperature is 600℃, sintering heating rate is 10℃ / min, holding time is 20min; cooling down to room temperature at a cooling rate of 10℃ to obtain sintered mixed powder;

[0074] S3, dry ball milling the sintered mixed powder, using stainless steel grinding balls, the mass ratio of stainless steel grinding balls to mixed powder is 4:1, and the vacuum degree of ball milling is 3.6×10 -6 Pa, the ball milling speed is 800 rpm, and the ball milling time is 5 h to obtain a mixed flux.

[0075] The particle size of the prepared mixed flux is detected to be between 0.3 and 0.6 mm, which is significantly better than the initial particle size and particle size concentration of pure iron flux, tin flux and tungsten flux.

[0076] Example 6

[0077] This embodiment provides a method for detecting the carbon and sulfur content in metallic chromium. The standard metallic chromium sample and the metallic chromium sample to be detected are the same as those in Example 2. The difference is that in step 5, 2.1 g of mixed flux is used to replace 0.3 g of pure iron flux, 0.3 g of tin flux, and 1.5 g of tungsten flux in Example 2. The mass of the metallic chromium to be detected is the same, and the methods and parameters of the remaining steps are the same as those in Example 1. Among them, the analysis time of the HCS-808 high-frequency infrared carbon and sulfur analyzer in step 5 of this embodiment is 26 s.

[0078] Among them, the preparation method of the mixed flux used in this embodiment is the same as that in Example 5.

[0079] Example 7

[0080] This embodiment provides a method for detecting the carbon and sulfur content in metallic chromium. The standard metallic chromium sample and the metallic chromium sample to be detected are the same as those in Example 3. The difference is that in step 5 of this embodiment, 2.1 g of mixed flux is used to replace 0.3 g of pure iron flux, 0.3 g of tin flux, and 1.5 g of tungsten flux in Example 3. The mass of the metallic chromium to be detected is the same, and the methods and parameters of the remaining steps are the same as those in Example 1. Among them, the analysis time of the HCS-808 high-frequency infrared carbon and sulfur analyzer in step 5 of this embodiment is 24 s.

[0081] Among them, the preparation method of the mixed flux used in this embodiment is the same as that in Example 5.

[0082] Example 8

[0083] This embodiment provides a method for detecting the carbon and sulfur content in metallic chromium. The standard metallic chromium sample and the metallic chromium sample to be detected are the same as those in Example 4. The difference is that in step 5, 2.1 g of mixed flux is used to replace 0.3 g of pure iron flux, 0.3 g of tin flux, and 1.5 g of tungsten flux in Example 4. The mass of the metallic chromium to be detected is the same, and the methods and parameters of the remaining steps are the same as those in Example 1. Among them, the analysis time of the HCS-808 high-frequency infrared carbon and sulfur analyzer in step 5 of this embodiment is 25 s.

[0084] Among them, the preparation method of the mixed flux used in this embodiment is the same as that in Example 5.

[0085] In Examples 1 to 8, each sample was tested in parallel.

[0086] Table 1 Determination results of carbon and sulfur content in samples of Examples 1 to 4

[0087]

[0088] In the above table, in the two parallel test data of Example 1, Example 2, Example 3 and Example 4 for the same metal chromium sample to be tested, the maximum deviation of carbon content is 6ppm (0.0006%), and the maximum deviation of sulfur content is 6ppm (0.0006%). The errors are within the required range and meet the metal chromium carbon and sulfur content detection standards.

[0089] At the same time, the test results of two parallel samples of the metal chromium to be tested in Example 5-Example 8 are shown in Table 2:

[0090] Table 2 Determination results of carbon and sulfur content in samples of Examples 5 to 8

[0091]

[0092]

[0093] In the above table, in the two parallel test data of the same metal chromium sample to be tested in Examples 5 to 8, the maximum deviation is reduced to 1 ppm (0.0001%) compared with Examples 1 to 6, indicating that after the mixed flux is used, the stability and reliability of the carbon and sulfur content detection of the metal chromium sample to be tested are further improved.

[0094] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0095] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A method for detecting carbon and sulfur content in metallic chromium, characterized in that: The following steps are involved: Step 1, weigh pure iron flux, tungsten flux, tin flux and standard metal chromium sample and place them in a ceramic crucible; Step 2: Gently shake the ceramic crucible to evenly distribute the pure iron flux, tungsten flux, tin flux and standard metal chromium sample; Step 3: Place the ceramic crucible on the infrared carbon and sulfur analyzer and start analysis and detection; Step 4: Using the carbon and sulfur contents of the standard metal chromium sample obtained by detection, a calibration curve of the infrared carbon and sulfur analyzer is drawn; Step 5, weigh pure iron flux, the metal chromium sample to be tested, tin flux, and tungsten flux in sequence, place them in a ceramic crucible and mix them evenly; Step 6: Analyze and detect the metal chromium sample to be tested using an infrared carbon-sulfur analyzer, and combine the calibration curve of the infrared carbon-sulfur analyzer obtained in step 4 to obtain the carbon and sulfur contents in the metal chromium sample to be tested.

2. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 3 and the step 5, the infrared carbon-sulfur analyzer used is a HCS-808 high-frequency infrared carbon-sulfur analyzer.

3. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the steps 1 and 5, the iron content of the pure iron flux used is greater than 99.8%, C is less than 0.0005%, S is less than 0.0005%, and the particle size is less than 1.25 mm.

4. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 1, the standard metal chromium sample has a carbon content of 0.087% and a sulfur content of 0.0053%.

5. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 1 and step 5, the tungsten flux used is tungsten granules, W in the tungsten granules is ≥ 99.5%, S is less than 0.0008%, C is less than 0.0005%, and the particle size of the tungsten granules is 0.4-0.8 mm.

6. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 1 and step 5, the tin flux used is tin particles, and the S in the tin particles is less than 0.0008%, the C is less than 0.0005%, and the particle size is 0.4-0.8 mm.

7. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 1, the mass ratio of the pure iron flux, the tungsten flux, the tin flux and the standard metal chromium sample is 3:2 to 3:2 to 3:

15.

8. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: In the step 5, the mass ratio of the pure iron flux, the metal chromium sample to be tested, the tin flux, and the tungsten flux is 3:2:3:

15.

9. The method for detecting carbon and sulfur content in metallic chromium according to claim 1, characterized in that: The amount of the metal chromium sample to be tested in step five is less than the amount of the standard metal chromium sample in step one.

10. The method for detecting carbon and sulfur content in metallic chromium according to claim 2, characterized in that: When the HCS-808 high-frequency infrared carbon and sulfur analyzer detects the carbon and sulfur content of standard metallic chromium samples and metallic chromium samples to be tested, the set working parameters are: the first-level gas pressure of oxygen and nitrogen supply is above 2Mpa, and the second-level gauge pressure of the pressure reducing valve is adjusted to 0.5MPa; ensure that the gas path is normal, the analysis pressure gauge on the HCS-808 high-frequency infrared carbon and sulfur analyzer is 0.08MPa, the top oxygen pressure is 0.15Mpa, the top oxygen rotor flowmeter is 2L / min, and the analysis rotor flowmeter is 3.5L / min; the waveforms of carbon and sulfur are stable, the entire curve is in a parallel trend, the difference between the peak and the trough of the entire waveform is less than 0.003, and the initial voltage of carbon and sulfur is between 0.5 and 1.5V.

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