Aluminum-containing high manganese steel spectrum internal control sample and preparation method thereof

Abstract

The invention discloses a preparation method of an aluminum-containing high manganese steel internal control standard sample for a spectrum. The preparation method is characterized in that the sample steel comprises the following chemical components in percentage by weight: 0.85%-1.20% of C, 0.050%-0.070% of Si, 24.0%-35.5% of Mn, 0.0040%-0.01% of P, 0.004%-0.01% of S, 0.015%-0.05% of Ni, 0.0025%-0.006% of Ti, 2.0%-10.0% of Al, 0.035%-0.08% of V, 0.003%-0.008% of N and the balance of Fe and inevitable impurities. According to the invention, an internal control standard sample with good uniformity and stable components is obtained by adopting a smelting technology of segmented feeding, annular whole-body electromagnetic stirring and water-cooling fixed mold.

Description

Technical Field

[0001] The invention relates to a laboratory internal control standard sample for elemental composition analysis of high manganese steel for spectroscopy, and in particular to a spectral internal control standard sample of aluminum-containing high manganese steel and a preparation method thereof. Background Art

[0002] Low-density aluminum-containing high-manganese steel is a new type of structural material that combines high strength and ductility with a low density by adding a high content (2%-10%) of the lightweight element Al to high-manganese alloy steel. The development of this material places higher demands on the online analysis of aluminum-containing high-manganese steel production, which is also a major factor restricting the mass production of aluminum-containing high-manganese steel.

[0003] Online analysis and testing in steel production primarily relies on direct reading spectrometers. Research and testing departments utilize inductively coupled plasma emission spectrometers (ICP-AES), atomic absorption spectrometers (AAS), and gas analyzers. However, all of these analytical methods, except direct reading spectrometers, suffer from complex and time-consuming processes. Several issues currently exist with direct reading spectrometers for directly analyzing the elemental content of aluminum-containing high-manganese steel. First, the high manganese content in the matrix significantly interferes with aluminum content detection. Without standard spectral samples for calibration, quantitative analysis of interfering elements like aluminum is impossible. Second, the metallurgical testing industry currently only has standard samples for high-manganese and high-aluminum steels, lacking spectral standards that address both high-content elements. This makes it difficult to develop effective methods for detecting elemental content in these products. In summary, because spark direct reading spectrometer analysis is a relative spectral comparison method subject to significant matrix effects, using currently available standard samples for quality control can easily lead to errors in judgment by inspectors. Therefore, if you want to simultaneously measure the two characteristic elements, manganese and aluminum, using a direct-emission spectrometer, you must have a laboratory internal control standard sample that matches the matrix. Currently, no such standard sample is available domestically or internationally. The main reason is that the aluminum in smelted samples easily segregates, making it difficult to achieve uniformity, making them unusable as standard samples.

[0004] Therefore, it is imperative to develop internal control standard samples of aluminum-containing high-manganese steel, solve the problems of easy segregation of aluminum elements and difficulty in meeting uniformity standards in the preparation of this type of standard samples, establish an analysis method for aluminum-containing high-manganese steel products using an online photoelectric direct reading spectrometer, and realize rapid and accurate analysis of multiple elements. Summary of the Invention

[0005] The present invention aims to prepare an internal control sample for spectroscopy of aluminum-containing high-manganese steel according to a designed composition, and its preparation method. Through a smelting technique involving segmented feeding, annular electromagnetic stirring throughout the steel, and water-cooled molds, an internal control standard sample with excellent uniformity and stable composition is obtained. Through segregation testing, uniformity testing, and composition determination, an internal control sample with a known composition is obtained that can be used in direct-reading spectrometers, glow spectrometers, glow mass spectrometers, and X-ray fluorescence spectrometers. This spectral internal control standard sample can be used to quickly and accurately determine the composition of aluminum-containing high-manganese steel, and has very important practical significance.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A spectrum internal control sample of aluminum-containing high-manganese steel, wherein the chemical components of the sample steel are as follows by weight: C: 0.85%-1.20%, Si: 0.050%-0.070%, Mn: 24.0%-35.5%, P: 0.0040%-0.01%, S: 0.004%-0.01%, Ni: 0.015%-0.05%, Ti: 0.0025%-0.006%, Al2.0%-10.0%, V: 0.035%-0.08%, N: 0.003%-0.008%, and the remainder is Fe and unavoidable impurities.

[0008] A method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel comprises the following steps:

[0009] 1) Smelting: Smelting raw materials include but are not limited to industrial pure iron, carburizer, metallic manganese or electrolytic manganese, and pure aluminum particles. The experimental steel is smelted in a vacuum induction melting furnace, wherein industrial pure iron and a small amount of carburizer are placed in a crucible of a vacuum induction melting furnace and heated until completely melted and refined. After refining, argon is filled for protection, and a segmented feeding method is adopted, that is, the raw materials of carbon, manganese, and aluminum are added in the order of carbon-manganese-aluminum. Annular electromagnetic stirring (current frequency 20-30Hz, magnetic field strength 0.1-0.3T) is used to reduce inclusions and component segregation in the steel. The tapping temperature is not lower than 40°C above the liquidus line, the mold is water-cooled, and the external cooling water flow is controlled (4-5m 3 / min), the cooling rate of the ingot was controlled at 50±10℃ / s, and an ingot of about 185kg was cast.

[0010] 2) After the riser is removed from the ingot, 1 / 6 to 1 / 5 of the length is removed from the top and bottom. The remaining ingot is lathe-stripped until smooth, and then heated, forged, and slowly cooled. The ingot is heated in a heating furnace at room temperature, and the temperature is raised in three steps from 800°C to 1000°C to 1200°C. Each temperature plateau is kept warm for 1 to 2 hours depending on the weight of the ingot. The forging temperature is controlled at 1100°C ± 50°C, and multiple (more than 5) upsetting and stretching operations are performed, with a deformation ratio of 6:1-8:1. The billet is cooled using a slow cooling technique of burying in a preheated sand pile. After forging, the round bar surface is required to be free of cracks, scars, and mixed samples, with a diameter within the range of 47mm ± 2mm, a length of 800 to 1000mm, and a straightness error of no more than 1.5mm.

[0011] 3) The ingots are homogenized, extruded and lathe-formed.

[0012] 4) Grind and refine the sample into a spectral block sample with a diameter of 30-40 mm and a height of 30-40 mm, and mark the spectral sample with a number.

[0013] 5) Randomly select 20 spectral block samples from each group of internal control samples and use direct reading or glow spectroscopy to perform uniformity test. According to the variance analysis method of F test, the uniformity of each element is determined. The obtained F value must be less than the critical value (F 0.05 )1.85.

[0014] 6) Perform a fixed value analysis of the characteristic values to determine each characteristic value. After the uniformity test passes the statistical test, a chip sample is taken and the laboratory is commissioned to jointly analyze and determine the value. The fixed value analysis data is tested for normal distribution using the normality test method and the Grubbs method is used to test for outliers. The mean and standard deviation of each element are calculated to finally obtain the characteristic value of the spectral sample element.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) The use of segmented feeding, annular electromagnetic stirring, and water-cooled fixed mold smelting technology successfully solved the problems of easy segregation of aluminum elements and poor sample uniformity in this type of steel sample. The obtained sample fully meets the uniformity requirements of spectral standard samples in GB / T 15000.

[0017] 2) The characteristic values of C, Si, Mn, P, S, Ni, Ti, Al, V, and N determined by the internal control sample for spectral analysis of aluminum-containing high-manganese steel of the present invention serve as a metrological tool for conveying the compositional values of corresponding aluminum-containing high-manganese steel products. The product of the present invention is applicable to direct-reading spectrometers, glow spectrometers, and other solid-state direct excitation quantitative spectrometers for establishing analytical methods and working curves, sample control calibration, and other operations, enabling online tempering of aluminum-containing high-manganese steel smelting production, significantly promoting online control of aluminum-containing high-manganese steel production quality and improving online production inspection capabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a comparison chart of the change of Al content after correction using the control sample of the present invention.

[0019] Figure 2 It is a comparison chart of the change of Mn content after correction using the control sample of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the specific implementation methods of the present invention are further described below in conjunction with examples. The following examples are used to specifically illustrate the contents of the present invention. These examples are only general descriptions of the contents of the present invention and do not limit the contents of the present invention.

[0021] Example 1:

[0022] A method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel comprises the following steps:

[0023] 1) Smelting raw materials include but are not limited to industrial pure iron, carburizer, metallic manganese or electrolytic manganese, and pure aluminum particles. The experimental steel is smelted in a vacuum induction melting furnace, wherein industrial pure iron and a small amount of carburizer are placed in a crucible of a vacuum induction melting furnace and heated until completely melted and refined. After refining, argon gas is filled for protection. The raw materials of carbon, manganese, and aluminum are added in the order of carbon-manganese-aluminum. Annular electromagnetic stirring (current frequency 21Hz, magnetic field strength 0.11T) is used to reduce inclusions and component segregation in the steel. The tapping temperature is not lower than 40°C above the liquidus line. The mold is water-cooled and the external cooling water flow is controlled at 4.1m 3 / min, the cooling rate of the ingot was controlled at 40℃ / s, and an ingot of about 185kg was cast.

[0024] 2) After the riser is removed from the ingot, 1 / 5 of the length is removed from the top and bottom. The remaining ingot is lathe-stripped until smooth before heating, forging, and slow cooling. The ingot is heated in a heating furnace at room temperature, with a three-step temperature increase from 800°C to 1000°C to 1200°C. Each temperature plateau is kept warm for 1 to 2 hours depending on the weight of the ingot. The forging temperature is controlled at 1100°C, and upsetting and drawing are performed five times with a compression ratio of 6:1. The billet is cooled using a slow cooling technique of burying in a preheated sand pile. After forging, the round bar surface must be free of cracks, scars, or mixed samples, with a diameter within the range of 47mm±2mm, a length of 800 to 1000mm, and a straightness error of no more than 1.5mm.

[0025] 3) The ingots are homogenized, extruded and lathe-formed.

[0026] 4) Grinding, finishing and numbering: The round bar samples with a diameter of 47mm±2mm and a length of 800-1000mm that are qualified after forging and rolling are peeled on a lathe, cut into blocks on a saw, chamfered on a lathe, polished, and cleaned with alcohol (to prevent rust). Finally, they are processed into 40mm×30mm block samples, which are the final samples and marked with numbers on the spectral samples.

[0027] 5) Uniformity test: 20 spectral block samples were randomly selected from each group of spectral internal control samples, and the uniformity test was performed using direct reading spectroscopy. The uniformity statistics of each element were performed based on the variance analysis method. The main fixed value items and elements C, Si, Mn, P, S, Ni, Ti, V, Al, and N, which are easy to segregate and have poor stability, were selected for uniformity test, and the method in GB / T15000 was used to express the uniformity of the samples. The uniformity statistics of each element were performed based on the variance analysis method of the F test. The F values were all less than 1.20, which was much less than the critical value (F 0.05 )1.85, meeting the uniformity requirements.

[0028] 6) Perform a fixed value analysis of the characteristic values to determine each characteristic value. After the uniformity test is statistically qualified, a chip sample is taken and the laboratory is commissioned to jointly analyze and determine the value. The fixed value analysis data is tested for normal distribution using the normal distribution test method and the presence of outliers using the Grubbs method. The mean and standard deviation of each element are calculated to ultimately obtain the characteristic value of the element in the spectral internal control sample. The summary data is shown in Example 1# in Table 1.

[0029] Example 2:

[0030] A method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel comprises the following steps:

[0031] 1) Smelting: Smelting raw materials include but are not limited to industrial pure iron, carburizer, metallic manganese or electrolytic manganese, and pure aluminum particles. The experimental steel is smelted in a vacuum induction melting furnace, wherein industrial pure iron and a small amount of carburizer are placed in a crucible of a vacuum induction melting furnace and heated until completely melted and refined. After refining, argon is filled for protection. The material is added in stages, that is, the raw materials of carbon, manganese, and aluminum are added in the order of carbon-manganese-aluminum. Annular electromagnetic stirring (current frequency 25Hz, magnetic field strength 0.2T) is used to reduce inclusions and component segregation in the steel. The tapping temperature is not lower than 40°C above the liquidus line. The mold is water-cooled and the external cooling water flow is controlled at 4.5m 3 / min, the cooling rate of the ingot was controlled at 50℃ / s, and an ingot of about 185kg was cast.

[0032] 2) After the riser is removed from the ingot, 1 / 5 of the length is removed from the top and bottom. The remaining ingot is lathe-stripped until smooth before heating, forging, and slow cooling. The ingot is heated in a heating furnace at room temperature, with a three-step temperature increase from 800°C to 1000°C to 1200°C. Each temperature plateau is kept warm for 1 to 2 hours depending on the weight of the ingot. The forging temperature is controlled at 1100°C, and six upsetting and drawing operations are performed with a compression ratio of 7:1. The billet is cooled using a slow cooling technique of burying in a preheated sand pile. After forging, the round bar surface must be free of cracks, scars, or mixed samples, with a diameter within the range of 47mm±2mm, a length of 800 to 1000mm, and a straightness error of no more than 1.5mm.

[0033] 3) The ingots are homogenized, extruded and lathe-formed.

[0034] 4) Grinding, finishing and numbering: The round bar samples with a diameter of 47mm±2mm and a length of 800-1000mm that are qualified after forging and rolling are peeled on a lathe, cut into blocks on a saw, chamfered on a lathe, polished, and cleaned with alcohol (to prevent rust). Finally, they are processed into 40mm×30mm block samples, which are the final samples and marked with numbers on the spectral samples.

[0035] 5) Uniformity test: 20 spectral block samples were randomly selected from each group of spectral internal control samples, and the direct reading spectroscopy method was used for uniformity test. The uniformity statistics of each element were performed according to the variance analysis method. The main fixed value items and elements C, Si, Mn, P, S, Ni, Ti, V, Al, and N, which are easy to segregate and have poor stability, were selected for uniformity test. The uniformity of the samples was expressed by the method in GB / T15000. According to the variance analysis method of the F test, the uniformity statistics of each element were performed. The F values were all less than 1.30, which was much smaller than the critical value (F 0.05 )1.85, meeting the uniformity requirements.

[0036] 6) Perform a fixed value analysis of the characteristic values to determine each characteristic value. After the uniformity test is statistically qualified, a chip sample is taken and the laboratory is commissioned to jointly analyze and determine the value. The fixed value analysis data is tested for normal distribution using the normal distribution test method and the presence of outliers using the Grubbs method. The mean and standard deviation of each element are calculated to ultimately obtain the characteristic value of the element in the spectral internal control sample. The summary data is shown in Example 2# in Table 1.

[0037] Example 3:

[0038] A method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel comprises the following steps:

[0039] 1) Smelting: Smelting raw materials include but are not limited to industrial pure iron, carburizer, metallic manganese or electrolytic manganese, and pure aluminum particles. The experimental steel is smelted in a vacuum induction melting furnace, wherein industrial pure iron and a small amount of carburizer are placed in a crucible of a vacuum induction melting furnace and heated until completely melted and refined. After refining, argon is filled for protection. The material is added in stages, that is, the raw materials of carbon, manganese, and aluminum are added in the order of carbon-manganese-aluminum. Annular electromagnetic stirring (current frequency 29Hz, magnetic field strength 0.29T) is used to reduce inclusions and component segregation in the steel. The tapping temperature is not lower than 40°C above the liquidus line. The mold is water-cooled and the external cooling water flow is controlled at 4.9m 3 / min, the cooling rate of the ingot was controlled at 60℃ / s, and an ingot of about 185kg was cast.

[0040] 2) After the riser is removed from the ingot, 1 / 5 of the length is removed from the top and bottom. The remaining ingot is lathe-stripped until smooth before heating, forging, and slow cooling. The ingot is heated in a heating furnace at room temperature, with a three-step temperature increase from 800°C to 1000°C to 1200°C. Each temperature plateau is kept warm for 1 to 2 hours depending on the weight of the ingot. The forging temperature is controlled at 1100°C, and seven upsetting and drawing operations are performed. The compression ratio is 8:1, and the billet is cooled using a slow cooling technique of burying in a preheated sand pile. After forging, the round bar surface must be free of cracks, scars, or mixed samples, with a diameter within the range of 47mm±2mm, a length of 800-1000mm, and a straightness error of no more than 1.5mm.

[0041] 3) The ingots are homogenized, extruded and lathe-formed.

[0042] 4) Grinding, finishing and numbering: The round bar samples with a diameter of 47mm±2mm and a length of 800-1000mm that are qualified after forging and rolling are peeled on a lathe, cut into blocks on a saw, chamfered on a lathe, polished, and cleaned with alcohol (to prevent rust). Finally, they are processed into 40mm×30mm block samples, which are the final samples and marked with numbers on the spectral samples.

[0043] 5) Uniformity test: 20 spectral block samples were randomly selected from each group of spectral internal control samples, and the direct reading spectroscopy method was used for uniformity test. The uniformity statistics of each element were performed according to the variance analysis method. The main fixed value items and elements C, Si, Mn, P, S, Ni, Ti, V, Al, and N, which are easy to segregate and have poor stability, were selected for uniformity test. The uniformity of the samples was expressed by the method in GB / T15000. According to the variance analysis method of the F test, the uniformity statistics of each element were performed. The F value was less than 1.38, which was much smaller than the critical value (F 0.05 )1.85, meeting the uniformity requirements.

[0044] 6) Perform a fixed value analysis of the characteristic values to determine each characteristic value. After the uniformity test is statistically qualified, a chip sample is taken and the laboratory is commissioned to jointly analyze and determine the value. The fixed value analysis data is tested for normal distribution using the normality test method and the presence of outliers using the Grubbs method. The mean and standard deviation of each element are calculated to ultimately obtain the characteristic value of the element in the spectral internal control sample. The summary data is shown in Example 3# in Table 1.

[0045] Table 1 Summary of the weight percentages of chemical elements in standard samples of aluminum-containing high manganese steel (%)

[0046] serial number project C Si Mn P S Ni Example 1# Standard value 0.90 0.052 24.22 0.0051 0.0052 0.021 Example 2# Standard value 1.01 0.056 30.28 0.0062 0.0075 0.022 Example 3# Standard value 1.12 0.061 34.95 0.0079 0.0091 0.029 serial number project Ti Al V N Example 1# Standard value 0.0035 2.51 0.041 0.0041 Example 2# Standard value 0.0036 6.21 0.058 0.0052 Example 3# Standard value 0.0042 9.26 0.069 0.0060

[0047] The composition of the aluminum-containing high manganese steel sample of the present invention is designed as a three-point series spectral internal control standard sample. Since the conventional high manganese steel method for detecting high content Al will encounter the interference of manganese, the introduction of the control sample correction of the present invention greatly improves the problem of inaccurate aluminum content determination. The results are shown in the attached Figure 1 At the same time, through sample correction, the detection value of manganese content is more accurate. Figure 2 .

Claims

1. A spectrum internal control standard sample of aluminum-containing high-manganese steel, characterized by: The chemical composition of the sample steel by weight percentage is: C: 0.85%~1.20%, Si: 0.050%~0.070%, Mn: 24.0%~35.5%, P: 0.0040%~0.01%, S: 0.004%~0.01%, Ni: 0.015%~0.05%, Ti: 0.0025%~0.006%, Al2.0%~10.0%, V: 0.035%~0.08%, N: 0.003%~0.008%, and the rest is Fe and unavoidable impurities.

2. A method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 1, characterized in that: The method comprises the following steps: 1) Smelting adopts a staged charging method. The raw materials of carbon, manganese and aluminum are added in the order of carbon-manganese-aluminum. The ring-shaped electromagnetic stirring is used to ensure that the furnace charge is evenly mixed. The tapping temperature is not lower than 40°C above the liquidus. Then it is quickly cooled and poured into a cylindrical ingot through a water-cooled fixed mold; 2) The ingot is heated in a heating furnace at room temperature, and the temperature is raised in three steps from 800℃ to 1000℃ to 1200℃. Each temperature platform is kept warm for 1 to 2 hours according to the weight of the ingot. The forging temperature is controlled at 1100℃±50℃, and more than 5 upsetting and stretching are performed. The deformation ratio can reach 6:1-8:

1. The billet is cooled by using a slow cooling technology of burying in a preheated sand pile. 3) Grind and refine the sample into a spectral block sample with a diameter of 30-40 mm and a height of 30-40 mm, and mark the spectral sample with a number; 4) Use direct reading or glow spectroscopy to test uniformity. According to the variance analysis method of F test, the uniformity of each element is determined. The obtained F value must be less than the critical value (F 0.05 )1.85; 5) Perform a constant value analysis of the characteristic quantity to determine each characteristic quantity value.

3. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: The step 1) is to carry out smelting in a vacuum induction melting furnace.

4. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: In the step 1), the annular electromagnetic stirring refers to multiple sets of coils surrounding the entire outer wall of the furnace in an annular array, symmetrically distributed, with a current frequency of 20-30Hz and a magnetic field strength of 0.1-0.3T to ensure uniform stirring of the molten steel in the furnace.

5. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: In the step 1), water cooling the mold means slowly pouring molten steel into the mold and controlling the external cooling water flow rate to 4-5m 3 / min to ensure that the outer wall temperature of the mold is less than 150℃, and the cooling rate of the ingot is controlled at 50±10℃ / s.

6. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: The ingot is processed as follows before entering the heating furnace: after the riser is cut off, 1 / 6 to 1 / 5 of the length is cut off at the top and bottom respectively, and the remaining ingot is peeled on a lathe until it is smooth.

7. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: In the step 2), the diameter of the steel billet after forging is within the range of 47 mm ± 2 mm, the length is 800 to 1000 mm, and the straightness error does not exceed 1.5 mm.

8. The method for preparing a spectrum internal control sample of aluminum-containing high-manganese steel according to claim 2, characterized in that: In step 5), the fixed value analysis data is tested for normal distribution using the normality test method, and the presence of outliers is tested using the Grubbs method. The mean value and standard deviation of each element are calculated to ultimately obtain the characteristic value of the element in the spectral internal control sample.

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