A method for correcting carbon abnormality in spectral analysis of molten iron sample

Abstract

The present application relates to molten iron chemical analysis technical field, specifically to a kind of molten iron sample spectrum analysis carbon abnormal correction method, including software installation and sample receiving, sample preparation processing, spectrometer analysis state check, into original point excitation program, sample placement and positioning, execute original point excitation and data acquisition, result display and determination, routine maintenance and parameter optimization etc.Step.The present application aims at solving the problem of carbon value anomaly caused by temperature / metallic white difference of molten iron sample, analysis rework etc.No carbon and sulfur reinspection, one analysis is qualified, can effectively improve detection efficiency and stability.Moreover, it can reduce consumable and labor cost, guarantee steel production continuous operation.

Description

Technical Field

[0001] This invention relates to the field of molten iron testing technology, and in particular to a method for correcting carbon anomalies in molten iron samples by spectral analysis. Background Technology

[0002] Spark direct-reading spectrometers are commonly used for analyzing the composition of molten iron in steel plants, requiring samples to have good white cast iron structure. However, in actual production, due to factors such as molten iron temperature, sampling cooling rate, and ambient temperature fluctuations, samples often exhibit insufficient white cast iron formation, localized gray cast iron formation, and graphite precipitation, resulting in abnormally high spectral excitation carbon values.

[0003] Existing technologies typically rely on repeated grinding and analysis for troubleshooting. When anomalies are found, a carbon-sulfur analyzer must be used for re-inspection. This process is time-consuming, material-costly, and requires equipment and manpower, severely slowing down the steelmaking process and affecting continuous production. Summary of the Invention

[0004] The purpose of this invention is to provide a method for correcting carbon anomalies in spectral analysis of molten iron samples, aiming to solve problems such as abnormal carbon values ​​and rework caused by temperature / white iron formation differences in molten iron samples. It eliminates the need for carbon and sulfur retesting, ensuring a pass on the first analysis, and effectively improving detection efficiency and stability. Furthermore, it reduces consumable and labor costs, ensuring continuous and smooth steelmaking production.

[0005] The technical solution adopted in this invention is as follows: The present invention proposes a method for correcting carbon anomalies in spectral analysis of molten iron samples, the method comprising the following steps: S1. Software installation and sample reception: Embed the origin excitation program in the spectrometer analysis software, preset the carbon reduction coefficient and excitation point parameters, and select the origin excitation carbon reduction mode in the spectrometer analysis software for samples with poor white casting. S2, Sample preparation and treatment; S3. Spectrometer Analysis Status Check: Check argon purity, pressure, vacuum level, and excitation stage cleanliness to ensure the instrument is in normal analytical condition; perform standardized calibration using control samples to confirm the instrument is working properly; S4. Enter the origin excitation program: Select the molten iron sample analysis channel on the spectrometer operation interface; click the newly added origin excitation carbon reduction mode in the software menu to enter the dedicated calibration program; S5. Sample placement and positioning; S6. Perform origin activation and data acquisition; S7. Result Display and Judgment; S8, routine maintenance and parameter optimization.

[0006] Furthermore, step S2 includes: grinding the sample using a high-speed milling machine of the high-speed separation system to make the ground surface smooth and free of oxide scale, oil stains, and obvious pores and cracks.

[0007] Furthermore, step S5 includes: placing the molten iron sample stably on the excitation stage using a robotic arm to ensure that the distance between the sample and the electrode is normal; adjusting the position of the sample so that the electrode is aligned with the flat area at the center of the cross-section.

[0008] Furthermore, step S6 includes: the spectrometer analysis software executing an automatic analysis program to perform origin excitation: pre-exciting the same position 2-3 times consecutively to clean the surface interference layer and stabilize the spark state; after the pre-excitation is completed, automatic integration acquisition is performed to read the spectral signal; the spectrometer analysis software automatically performs carbon reduction correction calculation on the carbon element detection value and corrects the carbon content according to the set coefficient.

[0009] Furthermore, step S7 includes: displaying the corrected full element analysis results, checking whether the carbon content is within a reasonable range, and if the carbon value is normal and there is no obvious abnormal fluctuation, directly confirming the results and uploading them to the LIMS system or production system; if it is still abnormal, changing the excitation point and repeating the origin excitation procedure once.

[0010] Furthermore, step S8 includes: verifying the accuracy of the origin excitation mode daily using control samples and comparing it with the results of the carbon-sulfur analyzer; fine-tuning the correction coefficient according to the season, molten iron temperature range, and degree of white iron formation to ensure data stability; and regularly cleaning the excitation stage, electrodes, and lens to ensure the long-term reliability of the calibration mode.

[0011] Compared with the prior art, the present invention has the following beneficial effects: This invention significantly improves the success rate of analysis on a single attempt, ensuring stable and qualified data, eliminating rework, shortening the testing cycle, and guaranteeing production schedule. Simultaneously, it effectively reduces the consumption of consumables for carbon and sulfur analysis, lowering production costs and providing stable and rapid testing support for continuous steelmaking production. Attached Figure Description

[0012] Figure 1 This is a schematic flowchart of a carbon anomaly correction method for spectral analysis of molten iron samples proposed in this invention. Detailed Implementation

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] It should be noted that in the description of this invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not mean that the device or element must have a specific orientation, or be constructed and operated in a specific orientation.

[0015] See appendix Figure 1 The present invention proposes a method for correcting carbon anomalies in spectral analysis of molten iron samples, comprising the following steps: S1. Software installation and sample reception: Embed the origin excitation program in the spectrometer analysis software, preset the carbon reduction coefficient and excitation point parameters, and select the origin excitation carbon reduction mode in the spectrometer analysis software for samples with poor white casting. S2. Sample preparation and treatment: The sample is polished by the high-speed milling machine of the high-speed separation system to make the polished surface flat and free of oxide scale, oil stains, and obvious pores and cracks.

[0016] S3. Spectrometer Analysis Status Check: Check argon purity, pressure, vacuum level, and excitation stage cleanliness to ensure the instrument is in normal analytical condition; perform standardized calibration using control samples to confirm the instrument is working properly; S4. Enter the origin excitation program: Select the molten iron sample analysis channel on the spectrometer operation interface; click the newly added origin excitation carbon reduction mode in the software menu to enter the dedicated calibration program; S5. Sample Placement and Positioning: Place the molten iron sample stably on the excitation stage using a robotic arm, ensuring that the distance between the sample and the electrode is normal; adjust the sample position so that the electrode is aligned with the flat area in the center of the cross-section, avoiding obvious graphite spots or areas with severe graying.

[0017] S6. Perform origin excitation and data acquisition: The spectrometer analysis software executes the automatic analysis program to perform origin excitation: the same position is pre-excited 2-3 times consecutively to clean the surface interference layer and stabilize the spark state; after the pre-excitation is completed, the system automatically performs integration acquisition and reads the spectral signal; the spectrometer analysis software automatically performs carbon reduction correction calculation on the carbon element detection value and corrects the carbon content according to the set coefficient.

[0018] S7. Result Display and Judgment: The system displays the corrected full element analysis results. Check whether the carbon content is within a reasonable range. If the carbon value is normal and there is no obvious abnormal fluctuation, directly confirm the result and upload it to the LIMS system or production system. If it is still abnormal, the excitation point can be changed and the origin excitation procedure can be repeated once. Generally, it is not necessary to perform carbon and sulfur analysis again.

[0019] S8. Daily maintenance and parameter optimization: Verify the accuracy of the origin excitation mode daily with control samples and compare the results with the carbon-sulfur analyzer; fine-tune the correction coefficients according to the season, molten iron temperature range, and degree of white iron formation to ensure data stability; regularly clean the excitation stage, electrodes, and lens to ensure the long-term reliability of the calibration mode.

[0020] During rapid cooling of molten iron samples, poor white iron formation is prone to occur, resulting in the presence of free graphite carbon within the sample. During conventional spectral excitation, the electrical and thermal conductivity of graphite carbon differs significantly from that of cementite, leading to unstable spark discharge, inhomogeneous matrix in the excitation region, and spectral signal deviations from the true value. Ultimately, this results in inflated and distorted carbon element detection results, failing to match the true value of the carbon-sulfur analyzer and limiting the accuracy of online rapid spectral detection.

[0021] This invention relies on a dual mechanism of origin-point fixed-point excitation and software-built-in carbon reduction correction model to solve the problem of abnormal carbon detection from two levels: excitation method and data algorithm.

[0022] The electrode is precisely aligned with the flat area at the center of the sample cross-section, and the same point is pre-excited 2-3 times consecutively. High-energy electric sparks are used to burn off the oxide scale and loose pores on the sample surface layer by layer, while breaking up the free graphite microcrystals on the surface, unifying the metallographic structure of the excitation area, making the excitation area approach a homogeneous cementite morphology, eliminating discharge interference caused by graphite, and stabilizing the repeatability of the spark source.

[0023] In December 2025, on-site sampling of molten iron from the converter was conducted. Spectroscopic samples were prepared using rapid casting with a water-cooled metal mold. Due to fluctuations in the on-site cooling rate, a large number of samples exhibited poor white caster formation, with flaky free graphite precipitating inside. Conventional spectral analysis revealed carbon values ​​exceeding 6%, exceeding the acceptable limit for closed-loop carbon adjustment in steelmaking. However, after conducting on-site benchmarking tests using the origin-point activation carbon reduction process of this invention, the carbon value could be reduced to below 5.0%, consistent with carbon and sulfur analysis results, effectively ensuring the smelting time for steelmaking.

[0024] Matters not covered in this invention are common knowledge.

[0025] 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 correcting carbon anomalies in spectral analysis of molten iron samples, characterized in that, The method includes the following steps: S1. Software installation and sample reception: Embed the origin excitation program in the spectrometer analysis software, preset the carbon reduction coefficient and excitation point parameters, and select the origin excitation carbon reduction mode in the spectrometer analysis software for samples with poor white casting. S2, Sample preparation and treatment; S3. Spectrometer Analysis Status Check: Check argon purity, pressure, vacuum level, and excitation stage cleanliness to ensure the instrument is in normal analytical condition; perform standardized calibration using control samples to confirm the instrument is working properly; S4. Enter the origin excitation program: Select the molten iron sample analysis channel on the spectrometer operation interface; click the newly added origin excitation carbon reduction mode in the software menu to enter the dedicated calibration program; S5. Sample placement and positioning; S6. Perform origin activation and data acquisition; S7. Result Display and Judgment; S8, routine maintenance and parameter optimization.

2. The method for correcting carbon anomalies in spectral analysis of molten iron samples according to claim 1, characterized in that: Step S2 includes: grinding the sample using a high-speed milling machine of the high-speed separation system to make the ground surface flat and free of oxide scale, oil stains, and obvious pores and cracks.

3. The method for correcting carbon anomalies in spectral analysis of molten iron samples according to claim 1, characterized in that: Step S5 includes: placing the molten iron sample stably on the excitation stage using a robotic arm to ensure that the distance between the sample and the electrode is normal; adjusting the position of the sample so that the electrode is aligned with the flat area at the center of the cross-section.

4. The method for correcting carbon anomalies in spectral analysis of molten iron samples according to claim 1, characterized in that: Step S6 includes: the spectrometer analysis software executes an automatic analysis program to perform origin excitation: pre-excite the same position 2-3 times consecutively to clean the surface interference layer and stabilize the spark state; after the pre-excitation is completed, automatic integration acquisition is performed to read the spectral signal; the spectrometer analysis software automatically performs carbon reduction correction calculation on the carbon element detection value and corrects the carbon content according to the set coefficient.

5. The method for correcting carbon anomalies in spectral analysis of molten iron samples according to claim 1, characterized in that: Step S7 includes: displaying the corrected full element analysis results, checking whether the carbon content is within a reasonable range, and if the carbon value is normal and there is no obvious abnormal fluctuation, directly confirming the results and uploading them to the LIMS system or production system; if it is still abnormal, changing the excitation point and repeating the origin excitation procedure once.

6. The method for correcting carbon anomalies in spectral analysis of molten iron samples according to claim 1, characterized in that: Step S8 includes: verifying the accuracy of the origin excitation mode daily with control samples and comparing the results with those of the carbon-sulfur analyzer; fine-tuning the correction coefficient according to the season, molten iron temperature range, and degree of white iron formation to ensure data stability; and regularly cleaning the excitation stage, electrodes, and lens to ensure the long-term reliability of the calibration mode.

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