Method for determining high-content aluminum in high-manganese steel

Abstract

The invention relates to the technical field of detection, in particular to a method for determining high-content aluminum in high manganese steel, which comprises the following steps: 1) preparing a scrap-shaped sample; 2) weighing a high manganese steel sample, placing the sample in a beaker, adding nitric acid, dropwise adding hydrofluoric acid, dissolving, transferring into a volumetric flask, and adding water to a constant volume to obtain a to-be-tested solution; (3) respectively weighing high-purity iron and ferromanganese standard samples, putting the high-purity iron and ferromanganese standard samples into a beaker, adding nitric acid, dropwise adding hydrofluoric acid, dissolving, transferring into a volumetric flask to obtain an iron-manganese composite reference solution, and repeating the operation to obtain a plurality of parts; (4) mixing a plurality of iron-manganese composite reference solutions with the Al standard solutions with different volumes respectively to prepare the Al standard solutions with different concentrations; (5) analyzing the Al standard solution under set analysis parameters by adopting an inductively coupled plasma emission spectrometer, and drawing an Al calibration curve; and (6) measuring the sample to be measured under the same test conditions for drawing the Al calibration curve, and obtaining the aluminum content in the high manganese steel sample according to the Al calibration curve.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and particularly relates to a method for determining high-content aluminum in high-manganese steel. The determination range of the aluminum content is 1.0%-5.0%. Background Art

[0002] High-manganese steel is a classic example of a material that "uses softness to overcome hardness," and its performance is highly dependent on dynamic impact environments. It is irreplaceable in wear-resistant components in mining, construction machinery, and other fields, but requires strict matching to operating conditions to avoid failure due to misuse. High-manganese steel is an engineering material with a moderate alloying element content and excellent performance, widely used in machinery manufacturing, the automotive industry, and building structures.

[0003] GB / T 223.9-2008 "Chemical Analysis Methods for Iron, Steel and Alloy - Chrome Azure S Photometric Method for Determination of Aluminum Content" Method 1: The determination range of acid-soluble aluminum is 0.05%-1.00%; Method 2: The determination range of aluminum element is 0.015%-0.50%.

[0004] GB / T 223.8-2000 "Chemical analysis methods for steel and alloys - Sodium fluoride separation - EDTA volumetric method for determination of aluminum content" The determination range of aluminum element is 0.50%-10.00%.

[0005] The above two chemical standard analysis methods both have disadvantages such as complicated operation steps, reagent pollution to the environment, and long analysis cycle.

[0006] Inductively coupled plasma atomic emission spectrometry (ICP-AES) analysis technology has the following advantages: rapidity, high throughput, and suitability for large sample batches; direct analysis of multiple elements without the need for complex chemical separations; strong anti-interference capabilities and high stability. Therefore, ICP-AES, with these advantages, has become a core tool for elemental analysis in modern laboratories. As an efficient multi-element analysis technique, ICP-AES can accurately determine major and trace elements, but attention must be paid to matrix interference control and sample pretreatment optimization. Establishing a fast, environmentally friendly instrumental analysis method for the determination of high aluminum content in high-manganese steel is imperative. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for determining high content aluminum in high manganese steel, thereby improving the stability and accuracy of the analysis results and increasing the analysis speed.

[0008] To achieve the above objectives, the present invention adopts the following technical solutions:

[0009] A method for determining high aluminum content in high manganese steel comprises the following steps:

[0010] 1) Sampling and sample preparation: remove the oxide layer on the sample surface and prepare a chip-like sample;

[0011] 2) Prepare high manganese steel test solution:

[0012] Weigh a high manganese steel sample and place it in a beaker. Add nitric acid and dropwise hydrofluoric acid. Slowly heat to dissolve without boiling. After complete dissolution, boil for 10-60 seconds. Cool to room temperature, transfer to a volumetric flask, and dilute with water to obtain the test solution.

[0013] 3) Prepare iron-manganese composite reference solution:

[0014] Weigh high-purity iron and ferromanganese standard samples separately and place them in a beaker. Add nitric acid and dropwise hydrofluoric acid. Heat slowly to dissolve without boiling. After complete dissolution, boil for 10-60 seconds. Cool to room temperature and transfer to a volumetric flask to obtain an iron-manganese composite reference solution. Repeat the process to obtain several portions.

[0015] 4) Prepare high manganese steel Al standard solution:

[0016] Several portions of the iron-manganese composite standard solution were mixed with different volumes of the Al standard solution to prepare Al standard solutions with different concentrations.

[0017] 5) Draw the Al calibration curve:

[0018] The Al standard solution was analyzed using an inductively coupled plasma optical emission spectrometer under set analytical parameters, and an Al calibration curve was drawn.

[0019] 6) Determination of aluminum content:

[0020] The test sample was measured under the same test conditions as those for drawing the Al calibration curve, and the aluminum content in the high manganese steel sample was obtained according to the Al calibration curve.

[0021] In step 2), the usage ratio of the manganese steel sample, nitric acid and hydrofluoric acid is: 0.1 g: 10-30 mL: 8-15 mL.

[0022] The usage ratio of the high-purity iron, ferromanganese standard sample, nitric acid, and hydrofluoric acid in step 3) is: 0.1 g: 0.1-0.2 g: 20-60 mL: 15-30 mL.

[0023] In step 4), the difference between the manganese content in the iron-manganese composite reference solution and the manganese content in the high manganese steel test solution is less than the allowable difference of chemical detection.

[0024] The concentration of the Al standard solution in step 4) is 1000 μg / mL.

[0025] The setting analysis parameters of the inductively coupled plasma emission spectrometer in step 5) are as follows: high-frequency emission power is 1050-1250 W; peristaltic pump speed is 50-70 r / min; atomizer flow is 0.5-0.7 L / min; auxiliary gas flow is 0.4-0.6 L / min; cooling gas flow is 10-15 L / min; observation height is 12-18 mm; integration time is 5-15 s for long wave and 5-15 s for short wave; and analysis spectral line is 396.152 nm.

[0026] Compared with the prior art, the beneficial effects of the present application are:

[0027] 1. Sub-boiling low temperature (without boiling) dissolves the sample, improves the stability and accuracy of the analysis results of high content aluminum in high manganese steel.

[0028] 2. The analysis speed is fast, and each sample after dissolution and constant volume only needs one minute for analysis.

[0029] 3. A high manganese steel Al calibration curve is prepared, which can be stored in a suitable temperature refrigerator for 1-3 months, can be used multiple times, saves time and cost, and fully meets the requirements of plasma emission spectrometric analysis. DETAILED DESCRIPTION

[0030] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification of the application is only for the purpose of describing specific embodiments and is not intended to limit the application. In this text, the term "embodiment" means that the specific features, structures or properties described in conjunction with the embodiment can be included in at least one embodiment of the application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it independent or alternative to other embodiments. Those skilled in the art understand explicitly and implicitly that the embodiments described herein can be combined with other embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0031] A method for determining high content aluminum in high manganese steel, comprising the following steps:

[0032] 1) Sampling and sample preparation:

[0033] Sampling and sample preparation are carried out according to the provisions of GB / T 20066; representative parts are selected, the surface should be removed 1mm thick oxide layer; and chip-shaped samples are prepared to avoid contamination.

[0034] 2) Preparation of high manganese steel test solution:

[0035] Weigh 0.1000g of high manganese steel sample and place it in a polytetrafluoroethylene beaker. Add 20mL of nitric acid (1+2) and dropwise add 10mL of hydrofluoric acid (1+3). Slowly heat to dissolve the high manganese steel sample without boiling. After complete dissolution, boil for 30s. Cool to room temperature, transfer to a 100mL plastic volumetric flask, and dilute to volume to obtain the test solution.

[0036] 3) Prepare iron-manganese composite reference solution:

[0037] Weigh 0.0500 μg of high-purity iron and 0.0500 μg of ferromanganese standard sample (select according to the Mn content of the sample so that the manganese content in the solution matches that of the sample as much as possible) into a polytetrafluoroethylene beaker, add 20 mL of nitric acid (1+2), and dropwise add 10 mL of hydrofluoric acid (1+3). Slowly heat to dissolve the composite sample without boiling. After complete dissolution, boil for 30 seconds, cool to room temperature, and transfer to a 100 mL plastic volumetric flask to obtain an iron-manganese composite reference solution. Repeat this operation to obtain six portions.

[0038] 4) Prepare high manganese steel Al standard solution:

[0039] Add 0, 1.0, 2.0, 3.0, 4.0, and 5.0 mL of aluminum (1000 μg / mL) standard solution to six portions of iron and manganese standard solution, add water to 100 mL, and shake well to prepare aluminum standard solutions with concentrations of 0%, 1.0%, 2.0%, 3.0%, 4.0%, and 5.0%;

[0040] 5) Draw the Al calibration curve:

[0041] An inductively coupled plasma optical emission spectrometer was used to analyze the Al standard solution under the set analysis parameters (high-frequency emission power of 1150 W; peristaltic pump speed of 60 r / min; nebulizer flow rate of 0.6 / min; auxiliary gas flow rate of 0.5 L / min; cooling gas flow rate of 12 L / min; observation height of 15 mm; integration time of long wave of 10 s and short wave of 10 s). Al: 396.152 nm was selected as the analysis line, and an Al calibration curve was obtained.

[0042] 6) Detection of high aluminum content in high manganese steel:

[0043] The high manganese steel sample was tested using an inductively coupled plasma emission spectrometer, and the aluminum content in the high manganese steel sample was obtained according to the Al calibration curve.

[0044] The method of the present invention and the sodium fluoride separation-EDTA titration method were used to determine the aluminum content of high manganese steel samples ≤ 5%, and the test results are shown in Table 1.

[0045] Table 1: Test results of aluminum content in high manganese steel samples

[0046] Sample number The present invention measured value % EDTA method determination value% deviation% Relative error% 1# 1.14 1.16 0.02 1.75 2# 2.28 2.25 -0.03 1.32 3# 3.45 3.41 -0.04 1.16 4# 4.85 4.92 0.07 1.44

[0047] As can be seen from Table 1, the deviation between the measured values ​​of high aluminum content in high manganese steel by the present invention and the measured values ​​by sodium fluoride separation-EDTA titration method is very small, and the relative errors are both less than 2%. The measured values ​​of the two different measurement methods are consistent with each other.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and basic spirit of the invention, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for determining high aluminum content in high manganese steel, characterized in that: The following steps are involved: 1) Sampling and sample preparation: remove the oxide layer on the sample surface and prepare a chip-like sample; 2) Prepare high manganese steel test solution: Weigh a high manganese steel sample and place it in a beaker. Add nitric acid and dropwise hydrofluoric acid. Slowly heat to dissolve without boiling. After complete dissolution, boil for 10-60 seconds. Cool to room temperature, transfer to a volumetric flask, and dilute with water to obtain the test solution. 3) Prepare iron-manganese composite reference solution: Weigh high-purity iron and ferromanganese standard samples separately and place them in a beaker. Add nitric acid and dropwise hydrofluoric acid. Heat slowly to dissolve without boiling. After complete dissolution, boil for 10-60 seconds. Cool to room temperature and transfer to a volumetric flask to obtain an iron-manganese composite reference solution. Repeat the process to obtain several portions. 4) Prepare high manganese steel Al standard solution: Several portions of the iron-manganese composite standard solution were mixed with different volumes of the Al standard solution to prepare Al standard solutions with different concentrations. 5) Draw the Al calibration curve: The Al standard solution was analyzed using an inductively coupled plasma optical emission spectrometer under set analytical parameters, and an Al calibration curve was drawn. 6) Determination of aluminum content: The inductively coupled plasma optical emission spectrometer was used to measure the test sample under the same test conditions as those used to draw the Al calibration curve, and the aluminum content in the high manganese steel sample was obtained according to the Al calibration curve.

2. The method for determining high aluminum content in high manganese steel according to claim 1, wherein: In step 2), the usage ratio of the manganese steel sample, nitric acid and hydrofluoric acid is: 0.1 g: 10-30 mL: 8-15 mL.

3. The method for determining high aluminum content in high manganese steel according to claim 1, wherein: The usage ratio of the high-purity iron, ferromanganese standard sample, nitric acid, and hydrofluoric acid in step 3) is: 0.1 g: 0.1-0.2 g: 20-60 mL: 15-30 mL.

4. The method for determining high aluminum content in high manganese steel according to claim 1, wherein: In step 4), the difference between the manganese content in the iron-manganese composite reference solution and the manganese content in the high manganese steel test solution is less than the allowable difference of chemical detection.

5. The method for determining high aluminum content in high manganese steel according to claim 1, wherein: The concentration of the Al standard solution in step 4) is 1000 μg / mL.

6. The method for determining high aluminum content in high manganese steel according to claim 1, wherein: In step 5), the analysis parameters of the inductively coupled plasma emission spectrometer were as follows: high-frequency emission power of 1050-1250 W; peristaltic pump speed of 50-70 r / min; nebulizer flow rate of 0.5-0.7 L / min; auxiliary gas flow rate of 0.4-0.6 L / min; cooling gas flow rate of 10-15 L / min; observation height of 12-18 mm; integration time of long wave of 5-15 s and short wave of 5-15 s; analysis line: 396.152 nm.