CN-121978252-A - Method for measuring content of calcium fluoride in flux for corrosion-resistant steel by ion chromatography

Abstract

The invention relates to the technical field of flux component measurement, in particular to a method for measuring the content of calcium fluoride in flux for corrosion-resistant steel by ion chromatography. A method for measuring the content of calcium fluoride in flux for corrosion-resistant steel by ion chromatography comprises the steps of S100, preparing a sample to be measured, S200, preprocessing the sample to be measured, preparing a diluted filtrate, S300, setting working parameters of an ion chromatograph, S400, calibrating an instrument, measuring by the ion chromatograph, and S500, measuring the content of calcium fluoride in the sample to be measured. A method for measuring the content of calcium fluoride in flux for corrosion resistant steel by ion chromatography has the advantage of ensuring the welding quality. The solder does not need to be experimentally detected before welding, and the flux is saved.

Inventors

• CHEN QIANQIAN
• GUO XINGJIE
• ZHANG YI
• ZHANG JIANHAO
• LI XIAOXU
• PAN HENGPEI
• LIU PAN

Assignees

• 洛阳船舶材料研究所(中国船舶集团有限公司第七二五研究所)

Dates

Publication Date

20260505

Application Date

20260320

Claims (10)

1. 1. A method for determining the calcium fluoride content of a flux for corrosion resistant steel by ion chromatography, comprising; s100, preparing a sample to be tested, treating a welding flux sample of the corrosion-resistant steel into uniform particles, removing impurities, dividing the sample into a plurality of parts, wherein the mass of each part is 10-20 g, sieving the sample through a 200-mesh screen, drying the sample at the temperature of 105-110 ℃ for 1h, and cooling the sample to room temperature in a dryer; S200, preprocessing a sample to be tested to prepare a diluted filtrate; S300, setting working parameters of an ion chromatograph, adopting gradient leaching, and quantitatively measuring the volume of a quantitative sample injection ring at 25 mu L according to peak area through a conductivity detector at a column box temperature of 30 ℃; S400, calibrating an instrument, namely, removing a fluoride ion standard solution, using water to fix the volume to 100 mL, gradually diluting the fluoride ion standard solution into serial standard solutions containing 0, 0.5, 1.0, 5.0 and 10.0 mug/mL, and measuring by using an ion chromatograph; S500, measuring the content of calcium fluoride in a sample to be measured, extracting 15mL of water, pushing the sample to pass through an H column, standing and placing the sample for 15min for full activation, pushing 10mL of the diluted solution in the step S200 into the activated H column, discarding the previous 2mL of filtrate, collecting the residual filtrate, injecting the filtrate into an ion chromatograph for analysis, and calculating to obtain the content of calcium fluoride in the welding flux.
2. 2. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, The flux sample for corrosion resistant steel in step S100 is free of grease, metal surface contamination, brush hair, and paper dust.
3. 3. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, In step S200, the method for preprocessing the sample to be tested includes: S210, weighing 4g of sodium potassium carbonate at the bottom of a crucible, and weighing 0.1g of flux sample; S220, covering 2g of sodium potassium carbonate on the sample, and preserving heat for 20 minutes at 990 ℃; s230, taking out, washing and leaching, dripping 10 drops of ethanol, and fixing the volume to a 200mL volumetric flask; s240, dry filtering 30mL of filtrate, and taking 2mL of filtrate to dilute to a 100mL volumetric flask.
4. 4. A method for determining the calcium fluoride content of flux for corrosion resistant steel by ion chromatography as claimed in claim 3, The resistivity of the water for washing in step S200 was 18.25 M.OMEGA.+ -. Cm.
5. 5. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, The gradient elution working conditions in step S300 are: s310, flushing time is 0-9 min, and flushing concentration is 2 mmol/L; s320, the flushing time is 9-9.1 min, and the flushing concentration is increased from 2 mmol/L to 50 mmol/L; s330, the flushing time is 9.2-24 min, and the flushing concentration is 50 mmol/L.
6. 6. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, In step S300, the eluent is potassium hydroxide, the flow rate is 1.0 mL/min, and the suppressor current is 99 mA.
7. 7. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, The standard solution of fluoride ions in the step S400 is GSB 04-2071-2007 type standard solution of fluoride ions, and the concentration is 100 mug/mL.
8. 8. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, In the calibration of the instrument in step S400, the measurement steps of the series of standard solutions are consistent with the measurement steps of the sample to be measured.
9. 9. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, In steps S400 and S500, the resistivity of the water for the experiment was 18.25 M.OMEGA.cm.
10. 10. The method for measuring the calcium fluoride content of flux for corrosion resistant steel by ion chromatography according to claim 1, Before the filtrate collected in step S500 is injected into the ion chromatograph, the working parameters of the ion chromatograph are ensured to be consistent with the parameters set in step S300.

Description

Method for measuring content of calcium fluoride in flux for corrosion-resistant steel by ion chromatography Technical Field The invention relates to the technical field of flux component measurement, in particular to a method for measuring the content of calcium fluoride in flux for corrosion-resistant steel by ion chromatography. Background Calcium fluoride is an important component in the flux, and can effectively reduce the high-temperature viscosity of slag, improve the fluidity of slag, improve the formation of welding seams and improve the mechanical properties of welding seam metals. Fluorine gas is generated under the action of high temperature, and can be combined with H atoms to generate H2F to be discharged out of the molten pool, so that the H content of the molten pool is reduced, and the probability of H pore generation is reduced. When the calcium fluoride content in the flux is less than 5%, the aforementioned effects are not obtained, and when the content is too high, arc stability is deteriorated, which affects weld formation. Thus, the calcium fluoride content of the flux has an important effect on the weld performance. The accurate and rapid determination of the components has important guiding significance for the quality monitoring of the welding seam and the safe service of the material. However, since the flux is generally directly used after purchasing or customizing, there are few components of the flux to be measured, and a few components of the flux to be measured are all substances generated after heating the flux to be measured, for example, chinese patent application publication No. CN121199368a relates to a streaming media audio chip vacuum welding device and an anti-oxidation method, and the device includes a main frame, a vacuum cavity module, an atmosphere control module, a laser module, a driving control module, an image detection module and a component detection module. The method comprises the steps of integrating an image and component detection module into a precise welding head, realizing positioning and appearance quality inspection before and after welding through a microscopic camera, detecting various gas components of the pre-coating flux, which are volatilized by heating, in real time by utilizing a Fourier transform infrared spectrometer, and inversely calculating the real-time welding temperature by analyzing the proportional relation of different gas components, thereby performing closed-loop control on laser power, and further accurately stabilizing welding heat input. The method has low detection efficiency, the measured components are components of the welding flux after being changed by heating, the content of the components of the welding flux, particularly the content of calcium fluoride, cannot be obtained before welding, and the welding quality cannot be ensured. The solder is tested experimentally before welding, resulting in waste of flux. Disclosure of Invention In view of the above, the present invention aims to provide a method for measuring the content of calcium fluoride in a flux for corrosion resistant steel by ion chromatography, which establishes an analysis method for the content of calcium fluoride in the flux by using an ion chromatograph, and solves the problems that the detection efficiency is low, the measured components are components of the flux after the flux is changed by heating, the content of the components of the flux, particularly the content of calcium fluoride, cannot be obtained before welding, and the welding quality cannot be ensured. The solder is experimentally detected before welding, which causes problems such as waste of the solder. In order to solve the above problems, the present invention provides a method for determining the content of calcium fluoride in flux for corrosion resistant steel by ion chromatography, comprising; s100, preparing a sample to be tested, treating a welding flux sample of the corrosion-resistant steel into uniform particles, removing impurities, dividing the sample into a plurality of parts, wherein the mass of each part is 10-20 g, sieving the sample through a 200-mesh screen, drying the sample at the temperature of 105-110 ℃ for 1h, and cooling the sample to room temperature in a dryer; S200, preprocessing a sample to be tested to prepare a diluted filtrate; S300, setting working parameters of an ion chromatograph, adopting gradient leaching, and quantitatively measuring the volume of a quantitative sample injection ring at 25 mu L according to peak area through a conductivity detector at a column box temperature of 30 ℃; S400, calibrating an instrument, namely, removing a fluoride ion standard solution, using water to fix the volume to 100 mL, gradually diluting the fluoride ion standard solution into serial standard solutions containing 0, 0.5, 1.0, 5.0 and 10.0 mug/mL, and measuring by using an ion chromatograph; S500, measuring the content of calcium fluoride in a sample to be mea