CN108414500B - Quantitative analysis method for sulfur and phosphorus in steel - Google Patents
Quantitative analysis method for sulfur and phosphorus in steel Download PDFInfo
- Publication number
- CN108414500B CN108414500B CN201711241792.1A CN201711241792A CN108414500B CN 108414500 B CN108414500 B CN 108414500B CN 201711241792 A CN201711241792 A CN 201711241792A CN 108414500 B CN108414500 B CN 108414500B
- Authority
- CN
- China
- Prior art keywords
- laser
- sample
- induced breakdown
- sulfur
- phosphorus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
- G01N21/71—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light thermally excited
- G01N21/718—Laser microanalysis, i.e. with formation of sample plasma
Abstract
The invention discloses a quantitative analysis method for sulfur and phosphorus in steel, which comprises the steps of establishing a standard sample preparation, adjusting laser-induced breakdown system parameters, collecting laser-induced breakdown spectrum signals, establishing a standard curve of SII 233.249nm and PII 253.560nm based on an internal standard method, collecting signals of a sample to be detected and obtaining an S/P quantitative analysis result in the sample to be detected according to the standard curve. The invention combines the internal standard method and the laser-induced breakdown spectroscopy technology, and can rapidly detect the content of sulfur and phosphorus elements in situ.
Description
Technical Field
The invention belongs to the technical field of spectral quantitative analysis, and relates to a quantitative analysis method for sulfur and phosphorus in steel, in particular to a quantitative analysis method for sulfur and phosphorus in steel by combining a laser-induced breakdown spectroscopy with an internal standard method.
Background
Various element components in the steel have important influence on the quality of the steel grade. In order to ensure the quality of steel, the content of main elements is often detected in real time and rapidly in the smelting process. As common impurity elements in steel, sulfur and phosphorus have great influence on the performance of the steel. The main sources of the sulfur element are raw materials and corresponding combustion products added in the smelting process, the machinability of the steel can be improved, and meanwhile, the hot brittleness of the steel can be caused, so that the steel is cracked in the hot working process and the like. The main source of phosphorus in steel is the steel-making raw material, which can increase the strength and hardness of steel, but also reduce the toughness and plasticity of steel, making the steel very brittle at low temperature. Therefore, establishing a method for measuring sulfur and phosphorus elements has important significance for controlling the quality of steel.
The Laser Induced Breakdown Spectroscopy (LIBS) is a novel material element analysis technique using laser as an excitation source, and is called as 'one huge star' in the future because of the advantages of rapidness, simultaneous analysis of multiple elements, no need of complex sample pretreatment and remote detection, and the like, thereby having great application potential in the field of metallurgy. At present, the application of the LIBS technology in the metallurgical industry mainly includes raw material screening, product quality monitoring, waste recovery and reuse, and the like.
The Laser Induced Breakdown Spectroscopy (LIBS) has the advantage of simple sample preparation, and can be used for rapidly and in-situ analyzing the element content in the smelting process, so that the LIBS has a good application prospect in the field of metallurgical analysis.
The method for detecting the contents of sulfur and phosphorus in steel at the present stage has the following problems:
1. a complex sample pretreatment process is required, and the detection efficiency is reduced;
2. the measurement period is long, the content of various elements cannot be fed back in time, the production process cannot be effectively controlled, raw material waste or unstable steel quality is caused, and the rapid development of the steel industry is limited.
Disclosure of Invention
The invention aims to provide a method for quantitatively analyzing sulfur and phosphorus in steel by combining laser-induced breakdown spectroscopy and an internal standard method aiming at the defects in the prior art. The method can be used for rapidly analyzing the contents of sulfur and phosphorus elements in the smelting process in situ, so that the method has a good application prospect in the field of metallurgical analysis.
The specific technical scheme of the invention is as follows:
a method for quantitatively analyzing sulfur and phosphorus in steel comprises the following steps:
step 2, adjusting a laser-induced breakdown system according to the established standard sample to enable the laser energy of the laser source to reach a proper value and enable the delay time between the laser pulse emission and the spectrum signal reception to reach a proper value;
step 3, radiating the established standard sample by adopting the adjusted laser-induced breakdown system, and collecting a laser-induced breakdown spectrum signal;
step 4, respectively selecting SII 233.249nm and PII 253.560nm as analysis lines, and selecting FeI 438.354nm as an inner marking line; in the laser-induced breakdown spectroscopy signal data collected in the step 3, spectral line intensities of SII 233.249nm and PII 253.560nm are divided by spectral line intensities of an inner marking line Fe I438.354nm respectively, the results are respectively used as vertical coordinates, percentage contents of S, P elements in a marking sample are respectively used as horizontal coordinates, and standard curves of SII 233.249nm and PII 253.560nm based on an internal standard method are respectively established;
and 5, radiating a sample to be detected by adopting the laser-induced breakdown system, collecting laser-induced breakdown spectrum signal data, and quantitatively analyzing the content of sulfur and phosphorus elements in the sample to be detected by utilizing the established standard curve.
The invention is further designed in that:
in the step 1, at least 5 steel samples with known component contents are selected as the standard building samples.
In step 1, a standard sample is built into a cylinder with the diameter of 20 multiplied by 6 mm.
Selecting 61mJ as laser energy parameter in step 2; the time delay parameter is 1.5 mus.
In step 3, randomly selecting 20-500 points for each standard establishing sample to acquire spectra, wherein each spectrum is the superposition of 10-100 excitation spectra.
The invention has the following outstanding advantages:
1. the invention combines the internal standard method and the laser-induced breakdown spectroscopy technology, and can rapidly detect the content of sulfur and phosphorus elements in situ.
2. The invention can directly carry out measurement aiming at samples in any shape without sample pretreatment, thereby saving the sample processing time.
3. The invention can perform in-situ online real-time analysis and improve the production line capacity.
4. The invention has high accuracy of detection results, and reduces the influence caused by the fluctuation of laser pulse energy, the non-uniformity of the sample surface and other non-target factors.
5. The invention can realize nondestructive detection, and the micro-area analysis reduces the damage to the sample.
Description of the drawings:
FIG. 1 is a S-element standard curve based on the intensity ratio SII 233.249nm/Fe I438.354nm in the example.
FIG. 2 is a P element standard curve based on the intensity ratio of P I253.560nm/Fe I438.354nm in the example.
Detailed Description
The invention is further illustrated by the following examples:
example one
In the laser-induced breakdown system of the embodiment, the excitation source is Nd: YAG solid laser (wavelength is 1064nm, pulse width is 10ns, laser energy is 4-80 mJ adjustable, laser emission frequency is 5Hz), laser pulse is focused on the surface of a sample through a lens, plasma is excited, and a spectrum signal is transmitted to an echelle grating spectrometer (wavelength range is 200-800 nm, resolution is about 0.1 nm). In the experimental process, in order to obtain spectra with good signal-to-noise ratio, each spectrum is obtained by adding 20 signals.
The invention relates to a quantitative analysis method for sulfur and phosphorus in steel by combining a laser-induced breakdown spectroscopy and an internal standard method, which specifically comprises the following steps:
1. sample preparation: manufacturing a sample to be detected and a standard building sample with known component content into a cylinder with the diameter of 20 multiplied by 6 mm; there are 5 standard-establishing samples, which are 20#, 20Cr, 15CrMo, 35CrMo and 20CrNiMo alloy steels produced by Jinan Zhongbiao science and technology Limited.
2. Adjusting the laser energy of the laser source, observing the relation with the intensity change of the spectral signal, and determining laser energy parameters;
laser energy optimization: the laser is used as an excitation source of the LIBS system, and the energy value of the pulse emitted by the laser directly influences the ablation amount of the substance and the intensity of the spectral signal. For a specific substance, when the laser energy is low, plasma cannot be induced to form, and when the energy exceeds a certain threshold, the intensity of a spectral signal linearly increases along with the laser energy and finally reaches a saturation state. Therefore, 10 values of laser energy are selected from 3-70 mJ, and the optimal laser energy parameter is selected to be 61mJ by observing the relation between the signal intensity and the laser energy.
Optimizing the delay time: in the early stages of plasma generation, the spectral signal consists mainly of continuous bremsstrahlung radiation, and the collection of atomic spectra is seriously affected by the continuous spectrum at this stage. The decay rates of both continuous and ionizing radiation are very fast over time, and the intensity of atomic line radiation, although it also drops, decays at a much slower rate than continuous and ionizing radiation. Therefore, LIBS measurement usually requires setting a delay time to avoid the early strong background to obtain a spectral signal with high signal-to-noise ratio. A suitable delay time is critical to obtain a high signal-to-back ratio characteristic line. Therefore, the set delay time is changed from 0 to 6 mu s, and when the delay time is zero, the intensity of the spectrum signal is strongest, but the continuous background signal is larger. The continuous background signal of the spectral line is weakened continuously and the signal-to-back ratio is strengthened continuously along with the lapse of the delay time. When the delay time is 1.5 mus, the continuous background of the spectral line is minimum, the signal-to-back ratio is strongest, when the delay time is more than 1.5 mus, the intensity of the spectral signal and the signal-to-back ratio are continuously weakened, the continuous background signal basically does not change, and the optimal delay time is selected to be 1.5 mus.
3. And (3) collecting laser-induced breakdown spectrum signals of the 5 standard building samples by adopting the determined laser energy parameters and delay time parameters, wherein 100 points are randomly selected for collecting spectra of each standard building sample, and each spectrum is the superposition of 20 excitation spectra.
4. The method mainly comprises alloy steel and chromium steel, and the spectral lines of Fe element in the chromium steel spectrum are more, so that the characteristic spectral lines of S, P element are seriously interfered by overlapping, and the spectral lines which can be used as analysis lines are less. According to the NIST database and the actual spectrogram of the chromium steel sample, SII 233.249nm and PII 253.560nm are respectively selected as analysis lines, and because the two lines are not obviously overlapped, the phenomenon of self-absorption does not exist. The characteristic line Fe I438.354nm of Fe element is selected as an inner marked line, and the excitation energy level of the inner marked line is close to the energy level of the analysis line. Wherein, I represents the atomic spectral line of the element, II represents the spectral line of the element after primary ionization, the element name, the ionization state and the wavelength value are commonly used to represent a specific spectral line, and example XII 233.249nm represents the spectral line of the primary ionization state sulfur element with the wavelength value of 233.249 nm.
In the laser-induced breakdown spectroscopy spectral lines measured in the step 4, the line intensity of FeI 438.354nm is used as an inner marking, the line intensity of the inner marking Fe I438.354nm is divided by the line intensity of the inner marking at the line intensity of the SII 233.249nm and the line intensity of the PII 253.560nm, the result is used as a vertical coordinate, the corresponding S, P element percentage content in the calibration sample with known component content is used as a horizontal coordinate, and a SII 233.249nm standard curve based on an inner marking method is established and shown in the attached figure 1; a calibration curve based on internal standard method PI 253.560nm was created as shown in FIG. 2.
5. After the S, P element standard curve based on the internal standard method was established, 5 benchmarked samples were repeatedly measured under the same conditions in step 4, and the reproducibility effect of the measurement results was evaluated using the Relative Standard Deviation (RSD) as an evaluation criterion, and the results are shown in table 1.
TABLE 1
6. For a sample to be detected, the system is adopted to collect laser-induced breakdown spectroscopy signal data, spectral line intensities of the S II 233.249nm and the P I253.560nm are respectively divided by spectral line intensities of the inner marked line Fe I438.354nm, the results are respectively used as vertical coordinates to be substituted into standard curves of the S II 233.249nm and the P I253.560nm, and horizontal marks on the corresponding curves are percentage contents of sulfur and phosphorus elements.
Example two
The invention relates to a quantitative analysis method for sulfur and phosphorus in steel by combining a laser-induced breakdown spectroscopy and an internal standard method, which comprises the following steps:
samples to be tested are chrome steel 20Cr, 20CrMo and 20CrNiMo purchased in the market, and the samples to be tested are manufactured into cylinders with phi of 20 multiplied by 6 mm.
The method and conditions for testing the samples to be tested are adopted to collect laser-induced breakdown spectroscopy signals of the 3 samples to be tested, and the results of quantitative analysis of S, P elements in the samples to be tested are obtained by analyzing the standard curve of SII 233.249nm and the standard curve of PII 253.560nm established in the first embodiment.
Test example one:
in this example, the quantitative analysis result of S, P elements in 3 samples to be tested was measured by two analyses of example, and compared with the detection result of inductively coupled plasma emission spectrometry (ICP-AES) with higher accuracy, and the quantitative evaluation effect is shown in table 2. As can be seen, compared with the existing ICP-AES method, the relative error of the analysis method is lower than 12.5 percent, which shows that the analysis method has good quantitative effect.
TABLE 2
EXAMPLE III
In the embodiment, an established SII 233.249nm standard curve and a P I253.560nm standard curve are adopted, a laser induced breakdown system and a computer system for establishing the standard curve are arranged on a production field, and a steel sample on the production line can be directly detected without pretreatment, so that the in-situ and on-line quantitative analysis of sulfur and phosphorus of the steel sample is realized.
The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.
Claims (4)
1. A method for quantitatively analyzing sulfur and phosphorus in steel comprises the following steps:
step 1, preparing a standard building sample;
step 2, adjusting a laser-induced breakdown spectroscopy system according to the established standard sample to enable the laser energy of the laser source to reach a proper value and enable the delay time between the laser pulse emission and the spectral signal reception to reach a proper value; selecting 61mJ as laser energy parameter; the time delay parameter is 1.5 mu s;
step 3, measuring the established standard sample by adopting the adjusted laser-induced breakdown spectroscopy system, and collecting laser-induced breakdown spectroscopy signals;
step 4, respectively selecting SII 233.249nm and PII 253.560nm as analysis lines, and selecting FeI 438.354nm as an inner marking line; in the laser-induced breakdown spectroscopy signal data collected in the step 3, spectral line intensities of SII 233.249nm and PII 253.560nm are divided by spectral line intensities of an inner marking line Fe I438.354nm respectively, the results are respectively used as vertical coordinates, percentage contents of S, P elements in a marking sample are respectively used as horizontal coordinates, and standard curves of SII 233.249nm and PII 253.560nm based on an internal standard method are respectively established;
and 5, measuring a sample to be detected by adopting the laser-induced breakdown spectroscopy system, collecting laser-induced breakdown spectroscopy signal data, and quantitatively analyzing the content of sulfur and phosphorus elements in the sample to be detected by utilizing the established standard curve.
2. The method of claim 1, wherein in step 1, at least 5 steel samples with known composition content are selected as the calibration sample.
3. The method for quantitative analysis of sulfur and phosphorus in steel according to claim 1, wherein in step 1, the standard sample is made into a cylinder with a diameter of 20X 6 mm.
4. The method for quantitative analysis of sulfur and phosphorus in steel according to claim 1, wherein in step 3, 20-500 points are randomly selected for each calibration sample to collect spectra, and each spectrum is a superposition of 10-100 excitation spectra.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711241792.1A CN108414500B (en) | 2017-11-30 | 2017-11-30 | Quantitative analysis method for sulfur and phosphorus in steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711241792.1A CN108414500B (en) | 2017-11-30 | 2017-11-30 | Quantitative analysis method for sulfur and phosphorus in steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108414500A CN108414500A (en) | 2018-08-17 |
| CN108414500B true CN108414500B (en) | 2020-10-27 |
Family
ID=63125350
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711241792.1A Active CN108414500B (en) | 2017-11-30 | 2017-11-30 | Quantitative analysis method for sulfur and phosphorus in steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN108414500B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109709456B (en) * | 2019-01-14 | 2020-12-15 | 无锡杰博仪器科技有限公司 | Data acquisition system of full-digital spectrum analyzer |
| CN111665233A (en) * | 2020-06-15 | 2020-09-15 | 天津大学 | Method for quantitatively detecting lactoferrin in dairy products based on laser-induced breakdown spectroscopy |
| CN113176250A (en) * | 2021-04-16 | 2021-07-27 | 武汉钢铁有限公司 | Method for quantitatively detecting converter slag component |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103808695B (en) * | 2014-03-11 | 2016-07-13 | 西北大学 | A kind of method detecting the full ferrum of iron ore based on LIBS |
| CN104697964A (en) * | 2015-03-10 | 2015-06-10 | 西北大学 | Method for quantitative analysis of sulfur and phosphorus in steel and iron by combining random forest algorithm with laser induced breakdown spectroscopy |
| CN104807787B (en) * | 2015-05-20 | 2017-05-31 | 重庆邮电大学 | A kind of Classification of Tea discrimination method based on LIBS |
-
2017
- 2017-11-30 CN CN201711241792.1A patent/CN108414500B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN108414500A (en) | 2018-08-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108414500B (en) | Quantitative analysis method for sulfur and phosphorus in steel | |
| CN102262076B (en) | Method for laser-induced breakdown spectroscopy element concentration determination based on spectral line combination | |
| Sarkar et al. | Evaluation of the prediction precision capability of partial least squares regression approach for analysis of high alloy steel by laser induced breakdown spectroscopy | |
| CN104697966A (en) | Method for quantitatively analyzing chromium and manganese in steel based on least square support vector machine algorithm combined with laser-induced breakdown spectroscopy | |
| CN103487411B (en) | A kind of random forests algorithm is in conjunction with the method for Laser-induced Breakdown Spectroscopy identification type of steels | |
| CN103808695B (en) | A kind of method detecting the full ferrum of iron ore based on LIBS | |
| Lu et al. | Analysis of total nitrogen and total phosphorus in soil using laser-induced breakdown spectroscopy | |
| CN102359953A (en) | Ordinary brass full-elemental analysis apparatus based on laser-induced breakdown spectroscopy, and method thereof | |
| CN109030462A (en) | Different type inclusion area and the quantitatively characterizing method of content in a kind of steel | |
| CN104697964A (en) | Method for quantitative analysis of sulfur and phosphorus in steel and iron by combining random forest algorithm with laser induced breakdown spectroscopy | |
| CN103792215A (en) | Method for rapidly measuring content of carbon element in steel | |
| CN102749309A (en) | Laser-induced breakdown spectrograph for rapid analysis of metallurgical components and analysis method therefor | |
| CN104048902A (en) | Method for measuring particle size distribution and content of globular oxide inclusions in steel | |
| Xu et al. | The high-accuracy prediction of carbon content in semi-coke by laser-induced breakdown spectroscopy | |
| CN106546574A (en) | The spectrum analyses and bearing calibration of trace nitrogen in a kind of steel | |
| Yin et al. | Rapid analysis of heavy metals in the coal ash with laser-induced breakdown spectroscopy | |
| CN103792214B (en) | A kind of improve the method for carbon element content certainty of measurement in iron and steel | |
| Hegazy et al. | Laser-induced breakdown spectroscopy: technique, new features, and detection limits of trace elements in Al base alloy | |
| Cai et al. | Estimating the aging grade of heat-resistant steel by using portable laser-induced breakdown spectroscopy | |
| CN104316511B (en) | Spectral line interference bearing calibration in spark source atomic emission spectrometry analysis | |
| Yan et al. | Classification accuracy improvement by data preprocessing in handheld laser-induced breakdown spectroscopy | |
| CN109668871A (en) | The direct-reading spectrometer analysis method of trace amount Ti in a kind of steel | |
| CN108709881A (en) | Method based on carbon element content in spark discharge Atomic Emission Spectral Analysis silicon steel | |
| CN105717094B (en) | A kind of metal element content analysis method based on large database concept identification | |
| CN105277531A (en) | Grading-based coal characteristic measurement method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |