A method for determining helium content in metal materials

Abstract

The present invention relates to the technical field of metal material component analysis, and discloses a method for determining the helium content in a metal material, comprising: pre-treating a metal material sample to be analyzed; adjusting the working parameters of a pulse melting-mass spectrometer gas element analyzer and setting an analysis method; performing a blank analysis on the pulse melting-mass spectrometer gas element analyzer according to the set analysis method; using a quantitative standard gas to calibrate the pulse melting-mass spectrometer gas element analyzer to obtain a standard working curve of helium; using the calibrated pulse melting-mass spectrometer gas element analyzer to determine the helium content of the pre-treated metal material sample to be analyzed according to the set analysis method. The present invention uses a pulse melting-mass spectrometer gas element analyzer to determine the helium content in the metal material, has high detection sensitivity, improves measurement accuracy, and can solve the problem that ultra-trace gas impurity elements cannot be accurately detected during the analysis of metal materials due to insufficient sensitivity of a thermal conductivity detector.

Description

Technical Field

[0001] The invention relates to the technical field of metal material component analysis, and in particular to a method for determining the helium content in a metal material. Background Art

[0002] The components in the material have an important influence on the performance of the material due to their different content and composition. Therefore, the content of each element in the material must be accurately detected. Current research shows that the He element produced by various mechanisms in the fusion process has an important influence on the microstructure and performance of fusion materials such as metal deuterium and tritium compounds (the main deuterium and tritium storage materials). There are many literatures at home and abroad that study this process by simulating the preparation of helium-containing materials, trying to provide a theoretical basis for a more optimized fusion process. The study of helium behavior in tritium storage materials includes the study of the existence and distribution of helium, the penetration of metals and its influence on the microstructure and morphology of metals, and "helium embrittlement" at high temperatures. In addition, in recent years, the "moon exploration" program worldwide needs to measure the total amount of He in the lunar atmosphere, soil and minerals. However, there are very few analytical studies on the content and state of He in metal materials at home and abroad.

[0003] The principle of gas analysis in metal materials is as follows: the instrument uses high-purity argon as carrier gas and pulse electrode furnace heating to melt the sample at high temperature in a graphite crucible. The elements to be measured in the sample are released in the form of gas, and the mixed gas is carried by the carrier gas into the mass spectrometer detector to obtain the content of the elements to be measured in the sample. Since the content of He in metal materials is extremely low (less than 0.1μg / g), the general thermal conductivity detector has low sensitivity and cannot accurately detect ultra-trace gas impurity elements, making it difficult to meet the He element detection needs. Therefore, how to use a more sensitive detection instrument to improve the lower limit of determination is a key issue in accurately determining the helium content in metal materials. Summary of the invention

[0004] The purpose of the present invention is to provide a method for determining the helium content in a metal material. The method adopts a pulse melting-mass spectrometry gas element analyzer to determine the helium content in the metal material. The method has high detection sensitivity and improves the measurement accuracy. The method can solve the problem that the ultra-trace gas impurity elements cannot be accurately detected due to the insufficient sensitivity of the thermal conductivity detector during the analysis of the metal material.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] A method for determining the helium content in a metal material, the method comprising the following steps:

[0007] Pre-treat the metal material samples to be analyzed;

[0008] Adjust the working parameters of the pulse fusion-mass spectrometry gas element analyzer and set the analysis method;

[0009] According to the set analysis method, a blank analysis is performed on the pulse melting-mass spectrometry gas element analyzer;

[0010] The pulse fusion-mass spectrometer gas element analyzer was calibrated using quantitative standard gas to obtain a standard working curve of helium;

[0011] The helium content of the pre-treated metal material sample to be analyzed is determined using a calibrated pulse melting-mass spectrometry gas element analyzer according to the set analysis method.

[0012] Furthermore, the pretreatment of the metal material sample to be analyzed specifically includes:

[0013] When the metal material sample to be analyzed is a block sample, remove the surface oxide layer, wash it with an organic solvent, and then air-dry it for later use;

[0014] When the metal material sample to be analyzed is in the form of chips, it should be cleaned with an organic solvent and then air-dried for later use;

[0015] When the metal material sample to be analyzed is a powder sample, it can be used directly.

[0016] Furthermore, the organic solvent is at least one of a methanol solution, an ethanol solution, an acetone solution, an ether solution, a chloroform solution, and a tetrachloromethane solution.

[0017] Furthermore, the adjusting the working parameters of the pulse melting-mass spectrometry gas element analyzer and setting the analysis method specifically include:

[0018] Match mass spectrometer parameters, calibrate mass axis, set detector voltage, set pulse furnace parameters, and set analysis method.

[0019] Further, the blank analysis of the pulse melting-mass spectrometry gas element analyzer is performed according to the set analysis method, specifically including:

[0020] According to the set analysis method, the graphite crucible in the pulse melting-mass spectrometry gas element analyzer was subjected to several blank analyses, and blank subtraction was performed after the blank was stable.

[0021] Furthermore, the quantitative standard gas contains a known content of helium.

[0022] Furthermore, the calibrated pulse melting-mass spectrometry gas element analyzer is used to determine the helium content of the pretreated metal material sample to be analyzed according to the set analysis method, specifically including:

[0023] Open the sample loading port of the pulse furnace and place a certain mass of the metal material sample to be analyzed into the sample chamber of the pulse furnace;

[0024] The pulse furnace is turned on, and the graphite crucible is placed on the lower electrode of the pulse furnace, and the lower electrode rises;

[0025] After the graphite crucible is degassed, the metal material sample to be analyzed falls into the crucible, is heated and melted, and the helium in the metal material sample to be analyzed is precipitated in the form of helium gas and carried into the pulse melting-mass spectrometry gas element analyzer by the carrier gas for mass spectrometry detection and signal acquisition. The data is processed based on the standard working curve of helium to obtain the helium content value.

[0026] Furthermore, before determining the helium content of the pre-treated metal material sample to be analyzed according to the set analysis method, the method further includes:

[0027] If the metal material sample to be analyzed is a block sample, choose the direct sampling method for analysis and testing;

[0028] If the metal material sample to be analyzed is a chip sample, first put the metal material sample to be analyzed into a nickel basket, compact it, and then choose the direct sampling method for analysis and testing;

[0029] If the metal material sample to be analyzed is a powder sample, first put the metal material sample to be analyzed into nickel foil or nickel bag, compact it, and then choose direct sampling method for analysis and testing.

[0030] Furthermore, the method also includes cleaning: after analyzing a number of metal material samples to be analyzed, cleaning the furnace, cleaning the upper and lower electrodes with an electrode brush, and wiping the furnace with a silk cloth.

[0031] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the method for determining the helium content in the metal material provided by the present invention adopts a pulse melting-mass spectrometry gas element analyzer to determine the helium content in the metal material, mainly including the steps of sample pretreatment, instrument debugging, blank analysis, establishment of a standard working curve of helium, analysis and determination of the sample, etc., and utilizes the universality, rapid response and high sensitivity of mass spectrometry detection to achieve rapid, high-sensitivity and high-precision analysis of the helium content. The present invention has low cost, simple operation, easy control, effectively optimizes the lower limit of analysis and determination, improves test accuracy, and the test results are accurate and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 This is a flow chart of a method for determining the helium content in a metal material according to an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of a standard working curve of helium in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] The embodiments of the present invention are described in detail below, and the embodiments are intended to explain the present invention and should not be construed as limiting the present invention. If specific techniques or conditions are not specified in the embodiments, they are carried out according to the techniques or conditions described in the literature in this area or according to the product specifications. If the manufacturers of reagents or instruments are not specified, they are all conventional products that can be obtained commercially.

[0036] The method for testing the helium content in a metal material provided by the present invention can solve the problem that the ultra-trace gas impurity elements cannot be accurately detected during the analysis of the metal material due to the insufficient sensitivity of the thermal conductivity detector.

[0037] like Figure 1 As shown, the method for determining the helium content in a metal material provided by the present invention comprises the following steps:

[0038] S1, sample pretreatment: pretreatment of the metal material sample to be analyzed; when the metal material sample to be analyzed is a block sample, remove the surface oxide layer, wash it with an organic solvent and air-dry it for later use; when the metal material sample to be analyzed is a scrap sample, wash it with an organic solvent and air-dry it for later use; when the metal material sample to be analyzed is a powder sample, use it directly. The organic solvent is at least one of methanol solution, ethanol solution, acetone solution, ether solution, chloroform solution, and tetrachloromethane solution.

[0039] S2, instrument debugging: adjust the working parameters of the pulse melting-mass spectrometry gas element analyzer, set the analysis method, specifically including: matching mass spectrometer parameters, calibrating the mass axis, setting the detector voltage, setting the pulse furnace parameters, and setting the analysis method. For example, the present invention uses the PMA-3000 pulse melting-quadrupole mass spectrometry gas element analyzer developed by Gangyan Nake Testing Technology Co., Ltd.; before the formal analysis, the instrument is preheated, the carrier gas and the power gas are turned on (the carrier gas is high-purity argon, the carrier gas flow rate is 400ml / min, and the power gas is ordinary nitrogen), the mass spectrometer detector is turned on, and the mass axis M / Z is 1~100.

[0040] Among them, for example, the element analyzer is composed of a pulse heating furnace, a sample addition system, a purification treatment device, a mass spectrometer, a signal acquisition and data processing system, and an automatic control system. The pulse heating furnace and the sample addition system are connected as a whole through the upper and lower electrodes to form a closed furnace. During analysis, the sample is put into a graphite crucible located between the upper and lower electrodes; the pulse heating furnace, the purification treatment device and the mass spectrometer are connected to each other by gas pipelines; the purified inert carrier gas is introduced from the bottom of the furnace to carry out the gas components released by the melting of the sample, and then purified again and introduced into the mass spectrometer. The signal acquisition and data processing system is connected to the detector of the mass spectrometer with a signal cable, amplifies and collects the signal, and calculates and outputs the mass percentage of the element to be measured in the sample through the data processing module of the computer software. The voltage and current monitoring instrument in the automatic control system is connected to the corresponding circuit of the analyzer with a cable; the air pressure and air flow monitoring instrument is connected to the corresponding gas path of the analyzer with a gas pipeline; the automatic control module in the computer software controls the action of the pneumatic valve group and the solenoid valve group of the actuator according to the set program to realize the automation of the analysis process.

[0041] The PMA-3000 pulse melting-quadrupole mass spectrometer gas element analyzer used in the embodiment of the present invention is an update based on the PMA-1000 pulse melting-time of flight mass spectrometer gas element analyzer (refer to patent CN101144795A-pulse melting-time of flight mass spectrometer element analyzer), which improves the time of flight mass spectrometer into a quadrupole mass spectrometer. The PMA-3000 pulse melting-quadrupole mass spectrometer gas element analyzer uses a pulse furnace as a pre-treatment device, and the components to be measured flow into the quadrupole mass spectrometer under the carrier gas and are detected.

[0042] S3, blank analysis: perform blank analysis on the pulse melting-mass spectrometry gas element analyzer according to the set analysis method; specifically, perform several blank analyses on the graphite crucible in the pulse melting-mass spectrometry gas element analyzer, and perform blank subtraction after the blank is stable.

[0043] S4, establishment of a standard working curve of helium: using a quantitative standard gas to calibrate a pulse fusion-mass spectrometry gas element analyzer to obtain a standard working curve of helium (a curve showing the relationship between the helium ion signal intensity and the absolute mass of helium); the quantitative standard gas contains helium with a known content (for example, the volume content of He is 0.01%). Specifically, a multi-point method is used to calibrate the instrument to establish a standard working curve of helium, such as Figure 2 As shown, the range of the absolute mass of helium in the standard working curve should include the helium content in the sample, which can be obtained through multiple experimental adjustments. For example, the functional relationship corresponding to the standard working curve of helium is: ,in x The corresponding parameter of the axis is the helium ion signal intensity. yThe axis corresponding parameters are helium absolute Quality, for example, c 1=0.0141, c 2=0.0096.

[0044] S5, analysis and testing: using a calibrated pulse melting-mass spectrometry gas element analyzer, according to the set analysis method, the helium content of the pre-treated metal material sample to be analyzed is determined, specifically including:

[0045] Open the sample loading port of the pulse furnace and place a certain mass of the metal material sample to be analyzed into the sample chamber of the pulse furnace;

[0046] The pulse furnace is turned on, and the graphite crucible is placed on the lower electrode of the pulse furnace, and the lower electrode rises;

[0047] After the graphite crucible is degassed, the metal material sample to be analyzed falls into the crucible, is heated and melted, and the helium in the metal material sample to be analyzed is precipitated in the form of helium gas and is carried into the pulse melting-mass spectrometry gas element analyzer by the carrier gas for mass spectrometry detection, signal acquisition and data processing to obtain the helium content value.

[0048] Specifically, mass spectrometry detection and signal acquisition are performed, and data processing is performed based on the standard working curve of helium to obtain the helium content value, including:

[0049] After mass spectrometry analysis and signal collection, the helium ion signal intensity in the metal material sample to be analyzed is obtained;

[0050] Based on the corresponding relationship between the helium ion signal intensity and the absolute mass in the standard working curve of helium, the absolute mass of helium corresponding to the helium ion signal intensity in the metal material sample to be analyzed is obtained;

[0051] The ratio of the absolute mass of helium gas to the mass of the metal material sample to be analyzed is calculated to obtain the content percentage of the helium element in the metal material.

[0052] Among them, before determining the helium content of the pre-treated metal material sample to be analyzed, it also includes:

[0053] If the metal material sample to be analyzed is a block sample, select the direct sampling method for analysis and testing; if the metal material sample to be analyzed is a chip sample, first put the metal material sample to be analyzed into a nickel basket, compact it, and then select the direct sampling method for analysis and testing; if the metal material sample to be analyzed is a powder sample, first put the metal material sample to be analyzed into a nickel foil or a nickel bag, compact it, and then select the direct sampling method for analysis and testing.

[0054] During the analysis and testing of actual samples, the mass percentage of helium in the metal material samples is calculated.

[0055] In addition, the method further comprises S6, cleaning: after analyzing a number of metal material samples to be analyzed, cleaning the furnace, cleaning the upper and lower electrodes with an electrode brush, and wiping the furnace with a silk cloth.

[0056] By timely cleaning of electrodes and regular replacement of filter reagents, the contamination of analytical instruments can be reduced, and the accuracy of determining the helium content in metal materials can be further improved. Example

[0057] The present invention takes a bulk sample as an example, and provides a method for determining the helium content in a metal material, comprising the following steps:

[0058] 1. Instrument Preparation

[0059] The instrument used in this example is a PMA-3000 pulse melting-mass spectrometry gas element analyzer developed by Gangyan Nake Testing Technology Co., Ltd. Preheat the instrument before analysis, turn on the carrier gas and power gas (the carrier gas is high-purity argon, the carrier gas flow rate is 400 ml / min, and the power gas is ordinary nitrogen). Turn on the mass spectrometer detector, and the mass axis M / Z is 1~100.

[0060] 2. Sample preparation

[0061] Remove the surface oxide layer of the block sample, cut it into small pieces, weigh and control the mass to about 1.00g, wash it with pure acetone or anhydrous ethanol solution, blow dry with cold air or air dry naturally, and put it in a sample box for later use.

[0062] 3. Analysis method setting

[0063] The heating method adopts power control mode, the degassing power is 4000W, the analysis power is 3500W, the shortest analysis time is 40s, and the comparison level is 1%.

[0064] 4. Blank and Calibration

[0065] According to the analysis method set in step 3, perform blank analysis on the high-purity graphite crucible three times, and perform blank subtraction after the blank is stable. Use quantitative standard gas (He volume content is 0.01%) to calibrate the helium content.

[0066] V. Sample Analysis

[0067] Enter the sample number and sample mass in the set analysis method, open the sample port, place the sample (1.0021g) weighed in step 2 into the sample container, turn on the pulse furnace, place the crucible on the lower electrode, and then raise the lower electrode. After the crucible is degassed, the sample falls into the crucible, heats and melts, and the instrument software calculates the measured value.

[0068] 6. Cleaning

[0069] Since graphite crucibles are volatile at high temperatures, the furnace should be cleaned after each sample analysis. The upper and lower electrodes should be cleaned with an electrode brush and the furnace should be wiped with a silk cloth.

[0070] The results of the embodiment analysis are as follows:

[0071] The helium content of a metal material sent for inspection by a laboratory was 0.00001%. It can be seen that the method provided by the present invention can further optimize the lower limit of analysis and measurement and improve the measurement accuracy.

[0072] In summary, the present invention uses a pulse melting-mass spectrometry gas element analyzer as a measuring instrument, a high-purity graphite crucible as a container, and a mass spectrometer for detection, and uses a standard gas with a certain standard value as a helium standard sample for standardization and calibration, thereby solving the problem of rapid determination of ultra-trace helium content in metal materials. The method has simple analysis steps, fast analysis speed, and high result accuracy, and provides reliable technical guarantees for the smelting, application, and quality control of metal materials, and effectively cooperates with the progress of scientific research and special production work.

[0073] Matters not covered by the present invention are known technologies.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention, as long as it complies with the principle of the preparation method for metals and alloys of the present invention, shall be included in the protection scope of the present invention.

Claims

1. A method for determining the helium content in a metal material, characterized in that: The following steps are involved: Pre-process the metal material samples to be analyzed, including: When the metal material sample to be analyzed is a block sample, remove the surface oxide layer, wash it with an organic solvent, and then air-dry it for later use; When the metal material sample to be analyzed is in the form of chips, it should be cleaned with an organic solvent and then air-dried for later use; When the metal material sample to be analyzed is a powder sample, it can be used directly; Adjust the working parameters of the pulse melting-mass spectrometry gas element analyzer and set the analysis method; preheat the pulse melting-mass spectrometry gas element analyzer before analysis, turn on the carrier gas and the power gas, the carrier gas is high-purity argon gas, and the power gas is nitrogen gas; the pulse melting-mass spectrometry gas element analyzer includes a quadrupole mass spectrometer; According to the set analysis method, the pulse melting-mass spectrometry gas element analyzer is blank analyzed, including: According to the set analysis method, the graphite crucible in the pulse melting-mass spectrometry gas element analyzer is subjected to several blank analyses, and blank subtraction is performed after the blank is stable; A pulse fusion-mass spectrometry gas element analyzer is calibrated using a quantitative standard gas to obtain a standard working curve of helium; the quantitative standard gas contains a known content of helium; The calibrated pulse melting-mass spectrometry gas element analyzer is used to determine the helium content of the pre-treated metal material sample to be analyzed according to the set analysis method, including: Open the sample loading port of the pulse furnace and place a certain mass of the metal material sample to be analyzed into the sample chamber of the pulse furnace; The pulse furnace is turned on, and the graphite crucible is placed on the lower electrode of the pulse furnace, and the lower electrode rises; After the graphite crucible is degassed, the metal material sample to be analyzed falls into the crucible, is heated and melted, and the helium in the metal material sample to be analyzed is precipitated in the form of helium gas and carried into the pulse melting-mass spectrometry gas element analyzer by the carrier gas for mass spectrometry detection and signal acquisition. The data is processed based on the standard working curve of helium to obtain the helium content value.

2. The method for determining the helium content in a metal material according to claim 1, characterized in that: The organic solvent is at least one of a methanol solution, an ethanol solution, an acetone solution, an ether solution, a chloroform solution, and a tetrachloromethane solution.

3. The method for determining the helium content in a metal material according to claim 1, characterized in that: The adjusting of the working parameters of the pulse melting-mass spectrometry gas element analyzer and setting of the analysis method specifically include: Match mass spectrometer parameters, calibrate mass axis, set detector voltage, set pulse furnace parameters, and set analysis method.

4. The method for determining the helium content in a metal material according to claim 1, characterized in that: Before determining the helium content of the pre-treated metal material sample to be analyzed according to the set analysis method, the method further includes: If the metal material sample to be analyzed is a block sample, choose the direct sampling method for analysis and testing; If the metal material sample to be analyzed is a chip sample, first put the metal material sample to be analyzed into a nickel basket, compact it, and then choose the direct sampling method for analysis and testing; If the metal material sample to be analyzed is a powder sample, first put the metal material sample to be analyzed into nickel foil or nickel bag, compact it, and then choose direct sampling method for analysis and testing.

5. The method for determining the helium content in a metal material according to claim 1, characterized in that: The method also includes cleaning: after analyzing a number of metal material samples to be analyzed, cleaning the furnace, cleaning the upper and lower electrodes with an electrode brush, and wiping the furnace with a silk cloth.

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