Rare metal hydrogen content standard substance as well as preparation method and application thereof
A rare metal hydrogen content standard substance prepared via vacuum arc melting and gas phase hydrogenation addresses the limitations of imported standards, offering accurate and cost-effective hydrogen content analysis for zirconium and titanium alloys, enhancing research and development reliability.
Patent Information
- Application Number
- CN202411198691.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2024-12-27
AI Technical Summary
The lack of domestic standard substances for accurately determining the hydrogen content in zirconium and titanium alloys, particularly for high hydrogen content ranges, leads to unreliable test results and restricts the research and development of these alloys, as imported standards are costly and limited in range, and existing methods introduce impurities and are inefficient.
A rare metal hydrogen content standard substance composed of specific elements (H, Ni, Fe) with controlled mass percentages, prepared through vacuum consumable arc melting and gas phase hydrogenation, ensuring uniformity and accuracy by controlling Fe content and using gas phase hydrogenation to achieve targeted hydrogen levels.
The solution provides a cost-effective, high-purity standard substance with controlled hydrogen content, reducing impurity introduction and ensuring accurate analysis, applicable for chemical analysis, quality monitoring, and calibration of instruments.
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Figure CN119194159A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of analysis and detection, and relates to a standard substance for detecting hydrogen content, and specifically relates to a rare metal hydrogen content standard substance and a preparation method and application thereof. Background Art
[0002] At present, rare metals such as titanium and zirconium have been widely used in many industries such as aerospace, nuclear field, medical, automobile manufacturing and high-end electronic products. In the nuclear field, titanium and zirconium play a vital role. Due to their good radiation resistance, these rare metals are used to manufacture key components such as fuel cladding, cooling pipes and nuclear waste storage containers of nuclear reactors, which effectively ensures the safe and efficient use of nuclear energy. Among them, zirconium alloys are widely used as fuel cladding materials and core structural materials for water-cooled nuclear reactors due to their small thermal neutron absorption cross-section, excellent corrosion resistance, moderate mechanical properties and good compatibility with uranium dioxide (UO2). However, zirconium alloy cladding materials will undergo corrosion and hydrogen absorption reactions in nuclear reactors for a long time, resulting in a continuous increase in the hydrogen content of zirconium alloy cladding materials. Once the hydrogen content exceeds the solid solubility limit of zirconium alloy, zirconium hydride phase will precipitate. Zirconium hydride is a brittle phase. After a large amount of zirconium hydride is enriched in zirconium alloy, the plasticity of the zirconium alloy cladding material will be significantly reduced, which may cause damage to the cladding material in the reactor and eventually cause nuclear fuel leakage. In addition, the research and development of zirconium alloys requires long-term corrosion tests outside the reactor and irradiation tests inside the reactor. During this process, all grades of zirconium alloys will produce a large amount of corrosion hydrogen absorption, usually between 0.015% and 0.035%. Due to the lack of corresponding zirconium alloy high-content hydrogen standards, the reliability of the test results is at risk, which has formed certain restrictions on the research and development and application promotion of zirconium alloys. Therefore, it is extremely important to accurately determine the hydrogen content of zirconium alloy cladding materials.
[0003] At the same time, in the fields of aviation, aerospace, chemical industry, etc., accurate analysis of the hydrogen content in titanium materials is of great significance. In these fields, titanium materials usually need to operate under extreme conditions, and only slight changes in hydrogen content may have a significant impact on their performance. Studies have shown that an appropriate amount of hydrogen can improve the hot working process performance of titanium alloys and reduce the stringent requirements of titanium alloy plastic deformation for deformation temperature and deformation speed. However, excessive hydrogen content may cause hydrogen embrittlement in titanium alloys, which will have an adverse effect on the performance and safety of titanium alloys. For titanium alloy hydrogen content standard substances, although there are standard substances with a certain content abroad, the price is relatively expensive, and the maximum hydrogen content is generally lower than 300ppm, which cannot cover all use ranges, especially when titanium alloys are used as hydrogen storage functional materials for reversible absorption and desorption of hydrogen, they are usually treated with hydrogen during powder metallurgy; or when hydrogen in titanium alloys exceeds the solid solubility and hydrogen embrittlement occurs, it is usually necessary to detect its hydrogen content. It can be seen that accurately determining the hydrogen content in titanium materials is also crucial.
[0004] However, at present, the standard substances for chemical analysis of hydrogen content in titanium, zirconium and other alloys are all imported products, which are not only costly but also have the risk of supply interruption; as for the above-mentioned hydrogen content standard substances, there are three 5ppm~15ppm zirconium alloy hydrogen content standard substances abroad, namely LECO 502-890 (discontinued in early 2024), AR640 (discontinued in 2021), and AR630 (sold out on the official website). Due to the long-term corrosion outside the pile and the irradiation test inside the pile, all grades of zirconium alloys will produce a large amount of corrosion and hydrogen absorption. For samples with high hydrogen content, there are no corresponding zirconium alloy standard samples at home and abroad, and they can only be replaced by high hydrogen content titanium alloy standard samples. The consequence of this is that due to the mismatch of the body, the reliability of the test results is at risk, which has formed certain restrictions on the research and development and application promotion of zirconium alloys. Therefore, it is urgent to develop a standard substance for detecting the hydrogen content of rare metals to solve the problem of standard substances for the hydrogen content of rare metals in my country. Summary of the invention
[0005] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a rare metal hydrogen content standard substance and a preparation method and application thereof for the analysis of hydrogen elements in rare metals.
[0006] To achieve the above object, the present invention provides the following technical solutions:
[0007] On the one hand, the present invention provides a rare metal hydrogen content standard material, which is composed of the following elements: H 7ppm~600ppm, Ni 10ppm~200ppm, Fe 50ppm~700ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of each element is 100%.
[0008] Furthermore, the matrix element is a rare metal element, for example, it may be titanium (Ti) element or zirconium (Zr) element or other rare metal elements.
[0009] Specifically, the rare metal hydrogen content standard material is composed of the following elements: H content is greater than or equal to 7ppm and less than 200ppm, Ni content is greater than or equal to 10ppm and less than 100ppm, Fe content is greater than or equal to 50ppm and less than 300ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of each element is 100%.
[0010] Specifically, the rare metal hydrogen content standard substance is composed of the following elements: H 200ppm~600ppm, Ni 100ppm~200ppm, Fe 300ppm~700ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of the elements is 100%.
[0011] Furthermore, by sampling and analyzing at least 9 positions of the finished rare metal ingot or forging, the relative standard deviation of the hydrogen element is no more than 5%; wherein, the 9 positions include: the head center, 1 / 2 radius of the head, head edge, middle center, 1 / 2 radius of the middle, middle edge, tail center, 1 / 2 radius of the tail, and tail edge of the finished ingot or forging.
[0012] On the other hand, the present invention provides a method for preparing a rare metal hydrogen content standard substance as described above in part or in whole, firstly preparing a rare metal hydrogen content standard substance ingot by vacuum consumable arc melting method, then preparing a rare metal hydrogen content standard substance wire by using the rare metal hydrogen content standard substance ingot, and finally performing hydrogen permeation treatment on the rare metal hydrogen content standard substance wire to obtain the rare metal hydrogen content standard substance.
[0013] Specifically, when the rare metal hydrogen content standard material is composed of the following elements: H content is greater than or equal to 7ppm and less than 200ppm, Ni content is greater than or equal to 10ppm and less than 100ppm, Fe content is greater than or equal to 50ppm and less than 300ppm, and the rest are matrix elements and unavoidable impurity elements, the sum of the mass percentages of each element is 100%, the hydrogenation treatment is specifically as follows:
[0014] The rare metal hydrogen content standard material wire is placed in a gas phase hydrogen permeation furnace, the vacuum device is turned on to extract the air in the furnace, 0.5MPa~0.8MPa of hydrogen-argon mixed gas is sent into the furnace, and then the furnace door is closed and heating is started to keep the temperature in the furnace at 350℃~450℃ for 6h~8h. After the insulation is completed and the temperature drops to room temperature, the rare metal hydrogen content standard material is taken out; wherein, the volume ratio of hydrogen to argon is (1~3):(97~99).
[0015] Specifically, when the rare metal hydrogen content standard material is composed of the following elements: H 200ppm~600ppm, Ni 100ppm~200ppm, Fe 300ppm~700ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of the elements is 100%, the hydrogenation treatment is specifically as follows:
[0016] The rare metal hydrogen content standard material wire is placed in a gas phase hydrogen permeation furnace, the vacuum device is turned on to extract the air in the furnace, and after sending 0.6MPa~0.9MPa of hydrogen-argon mixed gas into the furnace, the atmosphere is kept circulating and heating is turned on to keep the temperature in the furnace at 350℃~450℃, and the insulation time is 8h~12h. After the insulation is completed and the temperature drops to room temperature, the rare metal hydrogen content standard material is taken out; wherein, the gas flow rate of the hydrogen-argon mixed gas is 2L / min~20L / min, and the volume ratio of hydrogen to argon is (1~3):(97~99).
[0017] It should be noted that, in the present invention, a gas phase hydrogenation process with specific process parameters is used for hydrogenation treatment according to the composition of different elements of the rare metal hydrogen content standard material. The reasons are as follows:
[0018] First, since the gas phase hydrogenation method is in an atmosphere containing hydrogen, hydrogen enters the interior of the material through the diffusion and adsorption of gas molecules, the hydrogenation efficiency is high (a deeper hydrogenation depth can be achieved in a shorter time), and no new impurities will be introduced, the production cost is low, and the operation is safe; while the liquid phase hydrogenation method is to immerse the material in a liquid solution containing hydrogen (such as LiOH solution), and the hydrogen penetration is achieved through the contact and diffusion between the liquid and the material surface. The hydrogenation speed is slow (generally 20h to 24h), the equipment is used in a strong chemical corrosion environment for a long time, the equipment loss is large, and hazardous waste will be generated, and the production cost is high; in addition, new impurities will be introduced during the hydrogenation process, affecting the purity of the rare metal hydrogen content standard substance.
[0019] Second, for the rare metal hydrogen content standard substance H1, that is, the composition of each element is: H content is greater than or equal to 7ppm and less than 200ppm, Ni content is greater than or equal to 10ppm and less than 100ppm, and Fe content is greater than or equal to 50ppm and less than 300ppm; due to the low H content and in order to ensure the uniformity and stability of the atmosphere, the hydrogen-argon mixed gas does not need to circulate, so 0.5MPa~0.8MPa of hydrogen-argon mixed gas is used for closed heating, and the temperature in the furnace is maintained at 350℃~450℃, and the insulation time is 6h~8h. To ensure the temperature and sealing of the gas phase hydrogen permeation furnace, the rare metal hydrogen content standard substance H1 can be stably hydrogenated, so as to accurately control the content of hydrogen in the standard substance.
[0020] Third, for the rare metal hydrogen content standard substance H2, that is, the composition of each element is: H2 00ppm ~ 600ppm, Ni 100ppm ~ 200ppm, Fe 300ppm ~ 700ppm; due to the high H content, in order to improve the hydrogen permeation efficiency, the hydrogen-argon mixed gas needs to circulate, so 0.6MPa ~ 0.9MPa of hydrogen-argon mixed gas is used to maintain the atmosphere circulation and turn on the heating, and the temperature in the furnace is maintained at 350℃ ~ 450℃, and the insulation time is 8h ~ 12h to ensure the temperature and sealing of the gas phase hydrogen permeation furnace, so as to achieve stable and efficient hydrogen permeation treatment of the rare metal hydrogen content standard substance H2, so as to accurately control the content of hydrogen in the standard substance.
[0021] Fourth, the inventors of the present application need to emphasize that when the H content is close to 200ppm (180ppm-220ppm), theoretically, the hydrogenation process parameters corresponding to the rare metal hydrogen content standard substance H1 or the rare metal hydrogen content standard substance H2 can be selected to perform hydrogenation operation, so as to achieve the target content of the corresponding H element. However, in actual operation, taking into account various factors such as production cost and hydrogenation efficiency, and based on the actual hydrogenation target requirements, it is preferred to determine whether the H content falls within the range of the rare metal hydrogen content standard substance H1 or the rare metal hydrogen content standard substance H2, and then select the corresponding hydrogenation treatment process for hydrogenation operation to efficiently achieve the target content of the corresponding H element.
[0022] Finally, it should be noted that the gas flow rate of the above-mentioned hydrogen-argon mixture can be selected according to actual preparation requirements, such as 2L / min, 5L / min, 8L / min, 10L / min, 12L / min, 15L / min, 18L / min, 20L / min, etc., which are not listed one by one.
[0023] Furthermore, a rare metal hydrogen content standard material ingot is firstly prepared by vacuum consumable arc melting method, and the specific process is as follows:
[0024] Step 1, ingredients: using rare metal matrix elements as raw materials, adding iron and nickel as additives, calculating the ingredients according to the content of each element of the rare metal hydrogen content standard material and weighing the above raw materials respectively;
[0025] Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, mixed evenly and then pressed into electrode blocks; the pressed electrode blocks are welded together with a corresponding number of electrode blocks under the protection of an inert gas atmosphere to form consumable electrodes;
[0026] Step 3, vacuum consumable arc furnace smelting: placing the consumable electrode in a vacuum consumable arc furnace and smelting for 3 to 5 times cumulatively to obtain an ingot of a rare metal hydrogen content standard material;
[0027] Among them, after each smelting is completed, the ingot obtained from the current smelting is first cut into at least four equal parts along its radial direction to form at least four sub-ingots; then the outer circumference of each sub-ingot is turned inward and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the next smelting.
[0028] Furthermore, the rare metal hydrogen content standard material ingot is used to prepare the rare metal hydrogen content standard material wire, and the specific process is as follows:
[0029] First, the ingot of the rare metal hydrogen content standard material is homogenized and annealed to improve the uniformity of the ingot composition and structure and prevent the ingot from cracking during the forging process; wherein, the annealing temperature is 530°C to 580°C and the holding time is 4h to 6h;
[0030] Then, forging is performed at a temperature of 900° C. to 1100° C. to obtain a forging blank of a standard substance of rare metal hydrogen content;
[0031] Finally, the rare metal hydrogen content standard substance forging blank is used to produce the rare metal hydrogen content standard substance wire.
[0032] In addition, the present invention also provides the use of some or all of the above-mentioned rare metal hydrogen content standard substances in chemical analysis of zirconium and zirconium alloys, titanium and titanium alloys, etc.
[0033] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:
[0034] 1. The rare metal hydrogen content standard material provided by the present invention has a composition range that can meet the needs of rare metal chemical composition analysis standard materials; since the Fe content in the incoming material (rare metal elements) is relatively high, and the Fe element will cause segregation of the ingot composition during the smelting process, the present invention controls the Fe element content to be 50ppm~700ppm to prevent the segregation of the ingot composition; and, by adding an appropriate amount of Ni element (10ppm~200ppm), it can help accelerate the solid solution of H element in the zirconium alloy during the subsequent hydrogenation process.
[0035] 2. The preparation method of the rare metal hydrogen content standard substance provided by the present invention can avoid the influence of impurity elements by adding pure iron and pure nickel during the mixing process, thereby improving the purity, which is beneficial to control and adjust the alloy composition within the specified range, and ensures the accuracy of each element of the rare metal hydrogen content standard substance.
[0036] 3. During the smelting process, after each smelting is completed, the ingot obtained from the current smelting is first cut into at least four equal parts along its radial direction to form at least four sub-ingots; then the outer circumference of each sub-ingot is turned inward and each sub-ingot is assembled to ensure the uniformity of the alloy composition during the smelting process; and the standard material wire is hydrogenated using a gas phase hydrogenation process to accurately control the content of hydrogen in the standard material.
[0037] 4. The rare metal hydrogen content standard material provided by the present invention needs to undergo a hydrogenation treatment process to be prepared. As for the prepared rare metal hydrogen content standard material H1 and the rare metal hydrogen content standard material H2, the H element expanded uncertainty is shown in Table 1 below, and is significantly better than the H element expanded uncertainty of imported standard materials.
[0038] Table 1 Expanded uncertainty of H element of rare metal hydrogen content standard material of the present invention
[0039]
[0040]
[0041] In summary, the rare metal standard substances prepared by the present invention solve the "bottleneck" problem in my country's rare metal hydrogen content standard substances. Its application is not limited to the establishment of standard curves in chemical analysis, calibration of analytical instruments and analysis results, but also includes quality monitoring, quality control, interim verification, capability verification, measurement review, comparison of samples and blind sample testing and other aspects. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.
[0043] 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 or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.
[0044] Figure 1 A flow chart of the preparation method of the rare metal hydrogen content standard substance provided by the present invention;
[0045] Figure 2 A schematic diagram of the structure of a rare metal hydrogen content standard material ingot provided in Example 1 of the present invention;
[0046] Figure 3 The schematic diagram of the cutting of the ingot obtained by the current smelting into four equal parts along its radial direction to form four sub-ingots in Example 1 of the present invention;
[0047] Figure 4 This is a schematic diagram of the structure of a consumable electrode assembled from four sub-ingots according to Example 1 of the present invention;
[0048] Figure 5 A schematic diagram of a 9-point sampling method for rare metal hydrogen content standard material ingots provided in an embodiment of the present invention. DETAILED DESCRIPTION
[0049] Here, exemplary embodiments will be described in detail, and the embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are only examples consistent with some aspects of the present invention described in detail in the appended claims.
[0050] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with embodiments.
[0051] Example 1
[0052] This embodiment provides a rare metal hydrogen content standard material, which is composed of the following elements: H7ppm, Ni 80ppm, Fe 50ppm, and the rest are zirconium (Zr) elements and unavoidable impurity elements, and the sum of the mass percentages of each element is 100%. Since hydrogen (H) elements cannot be added during the ingot smelting of the standard material, in order to meet specific technical requirements, a hydrogen permeation process is required to perform fine hydrogen permeation treatment on the wire.
[0053] The preparation method of the above rare metal hydrogen content standard substance can be found in Figure 1 As shown, the specific steps are as follows:
[0054] Step 1, ingredients: sponge zirconium is used as raw material, iron (Fe) and nickel (Ni) are added as additives, and the ingredients are calculated according to 80 ppm of nickel (Ni), 50 ppm of iron (Fe), and the rest of zirconium (Zr), and the above raw materials are weighed respectively.
[0055] Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, and the rare metal matrix elements and additive electrode mixing method are adopted to achieve uniform distribution of alloy elements in the electrode blocks, and the electrode blocks are prepared by cold pressing; the pressed electrode blocks are plasma welded to form consumable electrodes under the protection of an inert gas (such as argon) atmosphere.
[0056] Step 3, smelting: using the rare metal hydrogen content standard material consumable electrode described in step 2 as raw material, placing it in a vacuum consumable arc furnace and smelting it for a total of 4 times to prepare a high uniformity rare metal hydrogen content standard material ingot, see Figure 2; The specific smelting process is:
[0057] Primary smelting: First, the ingot obtained from the first vacuum consumable smelting (i.e., primary ingot) is cut into four equal parts along its radial direction (e.g., two mutually perpendicular diameter directions) to form four sub-ingots, see Figure 3 ; Then, the outer circumference of each sub-ingot is turned inward, and each sub-ingot is turned around and assembled (see Figure 4 ), and then re-weld under the protection of an inert atmosphere to form a consumable electrode for the second smelting;
[0058] Secondary smelting: the consumable electrode for the second smelting is subjected to the second vacuum consumable smelting to obtain a secondary ingot, and the obtained secondary ingot is cut into four equal parts along its radial direction to form four sub-ingots; the outer circumference of each sub-ingot is turned inward, and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the third smelting;
[0059] Tertiary smelting: the consumable electrode for the third smelting is subjected to the third vacuum consumable smelting to obtain a tertiary ingot, and the obtained tertiary ingot is cut into four equal parts along its radial direction to form four sub-ingots; the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the fourth smelting;
[0060] Four smeltings: The fourth smelting is performed by using a consumable electrode to perform the fourth vacuum consumable smelting to obtain an ingot of standard material of rare metal hydrogen content with high uniformity.
[0061] Step 4, wire preparation: The rare metal hydrogen content standard material ingot obtained in step 3 is used as a raw material, and the ingot is subjected to homogenization annealing (temperature is 530°C, holding time is 6h) to eliminate potential dendrite segregation and local segregation, further improve the uniformity of the ingot composition and organization, and prevent the ingot from cracking during the forging process; then, it is forged at 1000°C to prepare a rare metal hydrogen content standard material forging blank, and sampling and analysis are performed on 9 parts of the forging blank (see Figure 5 ), the relative standard deviation of hydrogen element is 3.8%; the forged forging billet is further prepared into rare metal hydrogen content standard material wire (Φ2mm~Φ3mm) by extrusion, rolling, cold drawing, etc.
[0062] Step 5, hydrogenation: Place the rare metal hydrogen content standard material wire described in step 4 in a gas phase hydrogenation furnace, open the vacuum device to extract the air in the furnace, and inject 0.6MPa hydrogen-argon mixed gas (V H2 :V Ar=3:97) and then close the furnace door and start heating to keep the temperature in the furnace at 390°C for 6 hours. After the temperature is reduced to room temperature, take out the rare metal hydrogen content standard material and determine the value through chemical analysis, which is the zirconium alloy standard material H1.
[0063] It should be noted that the relevant parameters of the extrusion, rolling, cold drawing and other processes in step 4 are related to the specifications of the forging billet and the final rare metal hydrogen content standard material wire. In actual operation, adaptive selection can be made according to operation requirements.
[0064] For the rare metal hydrogen content standard substance described in this embodiment, sampling and analysis were performed at 9 locations of the finished ingot or forging billet, including the head center, head 1 / 2 radius, head edge, middle center, middle 1 / 2 radius, middle edge, tail center, tail 1 / 2 radius, and tail edge (see Figure 5 ), the obtained H element content W H 4.3ppm≤W H ≤9.7ppm, that is, the expanded uncertainty of hydrogen (H) element is 2.7ppm.
[0065] Example 2
[0066] This embodiment provides another rare metal hydrogen content standard material, which is composed of the following elements: H350ppm, Ni 120ppm, Fe 700ppm, and the rest is titanium (Ti) and unavoidable impurity elements. Since hydrogen (H) cannot be added during the ingot smelting of the standard material, in order to meet specific technical requirements, a hydrogen permeation process is required to perform fine hydrogen permeation treatment on the wire.
[0067] The preparation method of the above rare metal hydrogen content standard substance comprises the following specific steps:
[0068] Step 1, ingredients: sponge titanium is used as raw material, iron (Fe) and nickel (Ni) are added as additives, and the ingredients are calculated according to 120 ppm nickel (Ni), 700 ppm iron (Fe), and the rest titanium (Ti), and the above raw materials are weighed respectively.
[0069] Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, and the rare metal matrix elements and additive electrode mixing method are adopted to achieve uniform distribution of alloy elements in the electrode blocks, and the electrode blocks are prepared by cold pressing; the pressed electrode blocks are plasma welded to form consumable electrodes under the protection of an inert gas (such as argon) atmosphere.
[0070] Step 3, smelting: using the rare metal hydrogen content standard material consumable electrode described in step 2 as a raw material, placing it in a vacuum consumable arc furnace and smelting it for a total of 5 times to prepare a high-uniform rare metal hydrogen content standard material ingot; the specific smelting process is:
[0071] First smelting: firstly, the ingot obtained from the first vacuum consumable smelting (i.e., the first ingot) is cut into six equal parts along its radial direction to form six sub-ingots; then, the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the second smelting;
[0072] Secondary smelting: the consumable electrode for the second smelting is subjected to the second vacuum consumable smelting to obtain a secondary ingot, and the obtained secondary ingot is cut into six equal parts along its radial direction to form six sub-ingots; the outer circumference of each sub-ingot is turned inward, and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the third smelting;
[0073] Tertiary smelting: the consumable electrode for the third smelting is subjected to the third vacuum consumable smelting to obtain a tertiary ingot, and the obtained tertiary ingot is cut into six equal parts along its radial direction to form six sub-ingots; the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the fourth smelting;
[0074] Fourth smelting: the fourth smelting consumable electrode is subjected to the fourth vacuum consumable smelting to obtain a fourth ingot, and the obtained fourth ingot is cut into six equal parts along its radial direction to form six sub-ingots; the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the fifth smelting;
[0075] Five smeltings: The fifth smelting was carried out by using a consumable electrode to carry out the fifth vacuum consumable smelting to obtain a high uniformity rare metal hydrogen content standard material ingot. Sampling and analysis were carried out at 9 locations of the ingot (see Figure 5 ), the relative standard deviation of hydrogen element is 4.3%.
[0076] Step 4, wire preparation: using the rare metal hydrogen content standard material ingot obtained in step 3 as raw material, the ingot is subjected to homogenization annealing (temperature is 550°C, holding time is 5h) to eliminate potential dendritic segregation and local segregation, further improve the uniformity of the ingot composition and organization, and prevent the ingot from cracking during the forging process; then forging at 1100°C to prepare a rare metal hydrogen content standard material forging blank; the forged forging blank is further prepared into a rare metal hydrogen content standard material wire by extrusion, rolling, cold drawing, etc.
[0077] Step 5, hydrogenation: Place the rare metal hydrogen content standard material wire described in step 4 in a gas phase hydrogenation furnace, open the vacuum device to extract the air in the furnace, and inject 0.8MPa hydrogen-argon mixed gas (V H2 :V Ar =3:97) and then keep the atmosphere flowing and start heating to keep the temperature in the furnace at 400°C for 8 hours. After the temperature is reduced to room temperature, the rare metal hydrogen content standard material is taken out and the value is determined by chemical analysis to obtain the titanium alloy standard material H2. When the titanium alloy standard material H2 is hydrogenated, the gas flow rate of the hydrogen-argon mixed gas is 10L / min.
[0078] For the rare metal hydrogen content standard material described in this embodiment, sampling and analysis were carried out at 9 locations of the finished ingot or forging blank, including the head center, head 1 / 2 radius, head edge, middle center, middle 1 / 2 radius, middle edge, tail center, tail 1 / 2 radius, and tail edge. The obtained H element content W H : 329ppm≤W H ≤371ppm, that is, the expanded uncertainty of hydrogen (H) element is 21ppm.
[0079] Example 3
[0080] This embodiment provides another rare metal hydrogen content standard material, which is composed of the following elements: H600ppm, Ni 200ppm, Fe 500ppm, and the rest is zirconium (Zr) and unavoidable impurity elements. Since hydrogen (H) cannot be added during the ingot smelting of the standard material, in order to meet specific technical requirements, a hydrogen permeation process is required to perform fine hydrogen permeation treatment on the wire.
[0081] The preparation method of the above rare metal hydrogen content standard substance comprises the following specific steps:
[0082] Step 1, ingredients: Sponge zirconium is used as raw material, iron (Fe) and nickel (Ni) are added as additives, and the ingredients are calculated according to 200ppm of nickel (Ni), 500ppm of iron (Fe), and the rest of zirconium (Zr), and the above raw materials are weighed respectively. It should be noted here that adding nickel (Ni) elements during ingot smelting helps to improve the stability of hydrogen atoms in the internal structure of the standard substance.
[0083] Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, and the rare metal matrix elements and additive electrode mixing method are adopted to achieve uniform distribution of alloy elements in the electrode blocks, and the electrode blocks are prepared by cold pressing; the pressed electrode blocks are plasma welded to form consumable electrodes under the protection of an inert gas atmosphere.
[0084] Step 3, smelting: using the rare metal hydrogen content standard material consumable electrode described in step 2 as a raw material, placing it in a vacuum consumable arc furnace and smelting it for a total of 5 times to prepare a high-uniform rare metal hydrogen content standard material ingot; the specific smelting process is:
[0085] First smelting: firstly, the ingot obtained from the first vacuum consumable smelting (i.e., the first ingot) is cut into five equal parts along its radial direction to form five sub-ingots; then, the outer circumference of each sub-ingot is turned inward, and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the second smelting;
[0086] Secondary smelting: the consumable electrode for the second smelting is subjected to the second vacuum consumable smelting to obtain a secondary ingot, and the obtained secondary ingot is cut into five equal parts along its radial direction to form five sub-ingots; the outer circumference of each sub-ingot is turned inward, and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the third smelting;
[0087] Tertiary smelting: the consumable electrode for the third smelting is subjected to the third vacuum consumable smelting to obtain a tertiary ingot, and the obtained tertiary ingot is cut into five equal parts along its radial direction to form five sub-ingots; the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the fourth smelting;
[0088] Four smeltings: the consumable electrode for the fourth smelting is subjected to the fourth vacuum consumable smelting to obtain a fourth ingot, and the obtained fourth ingot is cut into five equal parts along its radial direction to form five sub-ingots; the outer circumference of each sub-ingot is turned inward and assembled, and then re-welded under the protection of an inert gas (such as argon) atmosphere to form a consumable electrode for the fifth smelting;
[0089] Five smeltings: The fifth smelting was carried out by using a consumable electrode to carry out the fifth vacuum consumable smelting to obtain a high uniformity rare metal hydrogen content standard material ingot. Sampling and analysis were carried out at 9 locations of the ingot (see Figure 5 ), the relative standard deviation of hydrogen element is 3.4%.
[0090] Step 4, wire preparation: using the rare metal hydrogen content standard material ingot obtained in step 3 as raw material, the ingot is subjected to homogenization annealing (temperature is 580°C, holding time is 4h) to eliminate potential dendritic segregation and local segregation, further improve the uniformity of the ingot composition and organization, and prevent the ingot from cracking during the forging process; then forging at 1100°C to prepare a rare metal hydrogen content standard material forging blank; the forged forging blank is further prepared into a rare metal hydrogen content standard material wire by extrusion, rolling, cold drawing, etc.
[0091] Step 5, hydrogenation: Place the rare metal hydrogen content standard material wire described in step 4 in a gas phase hydrogenation furnace, open the vacuum device to extract the air in the furnace, and inject 0.9 MPa hydrogen-argon mixed gas (V H2 :V Ar =2:98) and then keep the atmosphere flowing and start heating to keep the temperature in the furnace at 420°C for 10 hours. After the temperature is reduced to room temperature, the rare metal hydrogen content standard material is taken out and the value is determined by chemical analysis to obtain the zirconium alloy H2 standard material. When the zirconium alloy H2 standard material is hydrogenated, the gas flow rate of the hydrogen-argon mixed gas is 17L / min.
[0092] For the rare metal hydrogen content standard material described in this embodiment, sampling and analysis are carried out at least 9 positions of the finished ingot or forging blank, including the head center, head 1 / 2 radius, head edge, middle center, middle 1 / 2 radius, middle edge, tail center, tail 1 / 2 radius, and tail edge. The obtained H element content W H 572ppm≤W H ≤628ppm, that is, the expanded uncertainty of hydrogen (H) element is 28ppm.
[0093] Example 4
[0094] This embodiment also provides a rare metal hydrogen content standard substance, which is composed of the following elements: H75ppm, Ni 10ppm, Fe 300ppm, and the rest are titanium (Ti) element and unavoidable impurity elements.
[0095] Furthermore, since hydrogen (H) cannot be added during the melting of standard material ingots, in order to meet specific technical requirements, a hydrogenation process is required to perform fine hydrogenation treatment on the wire.
[0096] The preparation method of the above rare metal hydrogen content standard substance comprises the following specific steps:
[0097] Step 1, ingredients: Use sponge titanium as raw material, add iron (Fe) and nickel (Ni) as additives, calculate the ingredients according to 10ppm nickel (Ni), 300ppm iron (Fe), and the rest titanium (Ti), and weigh the above raw materials respectively. It should be noted here that adding nickel (Ni) elements during ingot smelting helps to improve the stability of hydrogen atoms in the internal structure of the standard substance.
[0098] Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, and the rare metal matrix elements and additive electrode mixing method are adopted to achieve uniform distribution of alloy elements in the electrode blocks, and the electrode blocks are prepared by cold pressing; the pressed electrode blocks are plasma welded to form consumable electrodes under the protection of an inert gas atmosphere.
[0099] Step 3, smelting: using the rare metal hydrogen content standard material consumable electrode described in step 2 as raw material, placing it in a vacuum consumable arc furnace and smelting it for a total of 4 times to prepare a high-uniform rare metal hydrogen content standard material ingot; the specific smelting process is:
[0100] First smelting: firstly, the ingot obtained from the first vacuum consumable smelting (i.e., the first ingot) is cut into four equal parts along its radial direction to form four sub-ingots; then, the outer circumference of each sub-ingot is turned inward and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the second smelting;
[0101] Secondary smelting: the consumable electrode for the second smelting is subjected to the second vacuum consumable smelting to obtain a secondary ingot, and the obtained secondary ingot is cut into four equal parts along its radial direction to form four sub-ingots; the outer circumference of each sub-ingot is then turned inward and assembled, and then re-welded under the protection of an inert gas (such as argon) atmosphere to form a consumable electrode for the third smelting;
[0102] Three smeltings: The third smelting is performed by using a consumable electrode to perform the third vacuum consumable smelting to obtain a highly uniform rare metal hydrogen content standard material ingot.
[0103] Step 4, wire preparation: The rare metal hydrogen content standard material ingot obtained in step 3 is used as a raw material, and the ingot is subjected to homogenization annealing (temperature is 560°C, holding time is 4.5h) to eliminate potential dendrite segregation and local segregation, further improve the uniformity of ingot composition and organization, and prevent the ingot from cracking during forging; then, it is forged at 950°C to prepare a rare metal hydrogen content standard material forging blank, and sampling and analysis are performed at 9 locations of the forging blank (see Figure 5 ), the relative standard deviation of hydrogen element is 3.9%; the forged forging billet is further prepared into rare metal hydrogen content standard material wire by extrusion, rolling, cold drawing, etc.
[0104] Step 5, hydrogenation: Place the rare metal hydrogen content standard material wire described in step 4 in a gas phase hydrogenation furnace, open the vacuum device to extract the air in the furnace, and inject 0.75MPa hydrogen-argon mixed gas (V H2 :V Ar=3:97) and then close the furnace door and start heating to keep the temperature in the furnace at 410°C for 7 hours. After the temperature is reduced to room temperature, take out the rare metal hydrogen content standard material and determine the value through chemical analysis, which is the titanium alloy H1 standard material.
[0105] For the rare metal hydrogen content standard substance described in this embodiment, sampling and analysis are performed at 9 positions, including the head center (1# position), head 1 / 2 radius (2# position), head edge (3# position), middle center (4# position), middle 1 / 2 radius (5# position), middle edge (6# position), tail center (7# position), tail 1 / 2 radius (8# position), and tail edge (9# position), 1 / 2 of the line connecting the 1# position and the 4# position (10# position), 1 / 2 of the line connecting the 2# position and the 5# position (11# position), 1 / 2 of the line connecting the 3# position and the 6# position (12# position), 1 / 2 of the line connecting the 4# position and the 7# position (13# position), 1 / 2 of the line connecting the 5# position and the 8# position (14# position), and 1 / 2 of the line connecting the 6# position and the 9# position (15# position), that is, 15 positions, and the H element content W is obtained. H :71.6ppm≤W H ≤78.4ppm, that is, the expanded uncertainty of hydrogen (H) element is 3.4ppm.
[0106] Through analysis, it can be known that the rare metal hydrogen content standard substances prepared in Examples 1 to 4 of the present invention, the expanded uncertainty of the hydrogen (H) element all meet the range of the expanded uncertainty requirements shown in Table 1, and the H element expanded uncertainty of the standard substances prepared in Example 2 (H 350ppm, U=21ppm) and Example 3 (H 600ppm, U=28ppm) is significantly lower than the H element expanded uncertainty of the imported standard substance (H 290ppm, U=30ppm), and the H element expanded uncertainty of the standard substance prepared in Example 4 (H 75ppm, U=3.4ppm) is less than the H element expanded uncertainty of the imported standard substance (H75ppm, U=6ppm). That is to say, the measurement results of the rare metal hydrogen content standard substances provided by the present invention are closer to the true value, and the reliability and accuracy of the measurement are stronger.
[0107] In summary, the inventors of this application believe that the rare metal hydrogen content standard material provided by the present invention has a wide range of application value, especially in the chemical analysis of zirconium and zirconium alloys, titanium and titanium alloys: its application is not limited to the establishment of calibration curves and working curves, but also includes quality monitoring, quality control, period verification, proficiency verification, measurement review, comparison samples and blind sample testing. These application solutions are all aimed at improving the precision, accuracy and traceability of chemical analysis of zirconium and zirconium alloys in various laboratories in the industry.
[0108] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.
[0109] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.
Claims
1. A rare metal hydrogen content standard substance, characterized in that: It is composed of the following elements: H 7ppm~600ppm, Ni 10ppm~200ppm, Fe 50ppm~700ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of the elements is 100%.
2. The rare metal hydrogen content standard substance according to claim 1, characterized in that: It is composed of the following elements: The H content is greater than or equal to 7ppm and less than 200ppm, the Ni content is greater than or equal to 10ppm and less than 100ppm, the Fe content is greater than or equal to 50ppm and less than 300ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of each element is 100%.
3. The rare metal hydrogen content standard substance according to claim 1, characterized in that: It is composed of the following elements: H 200ppm~600ppm, Ni 100ppm~200ppm, Fe300ppm~700ppm, the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of each element is 100%.
4. The rare metal hydrogen content standard substance according to claim 1, characterized in that: By sampling and analyzing at least 9 locations of the finished rare metal ingot or forging billet, the relative standard deviation of hydrogen element is no more than 5%.
5. The method for preparing a rare metal hydrogen content standard substance according to any one of claims 1 to 4, characterized in that: Firstly, a rare metal hydrogen content standard material ingot is prepared by vacuum consumable arc melting method, then a rare metal hydrogen content standard material wire is prepared by using the rare metal hydrogen content standard material ingot, and finally the rare metal hydrogen content standard material wire is subjected to hydrogen permeation treatment to obtain the rare metal hydrogen content standard material.
6. The method for preparing the rare metal hydrogen content standard substance according to claim 5, characterized in that: When the rare metal hydrogen content standard material is composed of the following elements: H content is greater than or equal to 7ppm and less than 200ppm, Ni content is greater than or equal to 10ppm and less than 100ppm, Fe content is greater than or equal to 50ppm and less than 300ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of the elements is 100%, the hydrogenation treatment is specifically as follows: The rare metal hydrogen content standard material wire is placed in a gas phase hydrogen permeation furnace, the vacuum device is turned on to extract the air in the furnace, 0.5MPa~0.8MPa of hydrogen-argon mixed gas is sent into the furnace, and then the furnace door is closed and heating is started to keep the temperature in the furnace at 350℃~450℃ for 6h~8h. After the insulation is completed and the temperature drops to room temperature, the rare metal hydrogen content standard material is taken out; wherein, the volume ratio of hydrogen to argon is (1~3):(97~99).
7. The method for preparing the rare metal hydrogen content standard substance according to claim 5, characterized in that: When the rare metal hydrogen content standard material is composed of the following elements: H 200ppm~600ppm, Ni 100ppm~200ppm, Fe 300ppm~700ppm, and the rest are matrix elements and unavoidable impurity elements, and the sum of the mass percentages of the elements is 100%, the hydrogenation treatment is specifically as follows: The rare metal hydrogen content standard material wire is placed in a gas phase hydrogen permeation furnace, the vacuum device is turned on to extract the air in the furnace, and after sending 0.6MPa~0.9MPa of hydrogen-argon mixed gas into the furnace, the atmosphere is kept circulating and heating is turned on to keep the temperature in the furnace at 350℃~450℃, and the insulation time is 8h~12h. After the insulation is completed and the temperature drops to room temperature, the rare metal hydrogen content standard material is taken out; wherein, the gas flow rate of the hydrogen-argon mixed gas is 2L / min~20L / min, and the volume ratio of hydrogen to argon is (1~3):(97~99).
8. The method for preparing the rare metal hydrogen content standard substance according to claim 5, characterized in that: First, the vacuum consumable arc melting method is used to produce the rare metal hydrogen content standard material ingot. The specific process is as follows: Step 1, ingredients: using rare metal matrix elements as raw materials, adding iron and nickel as additives, calculating the ingredients according to the content of each element of the rare metal hydrogen content standard material and weighing the above raw materials respectively; Step 2, consumable electrode preparation: according to the required ingot size and the number of electrode blocks, the weighed raw materials are evenly divided, mixed evenly and then pressed into electrode blocks; the pressed electrode blocks are welded together with a corresponding number of electrode blocks under the protection of an inert gas atmosphere to form consumable electrodes; Step 3, vacuum consumable arc furnace smelting: placing the consumable electrode in a vacuum consumable arc furnace and smelting for 3 to 5 times to obtain an ingot of a rare metal hydrogen content standard material; Among them, after each smelting is completed, the ingot obtained from the current smelting is first cut into at least four equal parts along its radial direction to form at least four sub-ingots; then the outer circumference of each sub-ingot is turned inward and each sub-ingot is assembled, and then re-welded under the protection of an inert atmosphere to form a consumable electrode for the next smelting.
9. The method for preparing the rare metal hydrogen content standard substance according to claim 5, characterized in that: The rare metal hydrogen content standard material wire is made by using the rare metal hydrogen content standard material ingot. The specific process is as follows: Firstly, the ingot of the standard substance of rare metal hydrogen content is homogenized and annealed to improve the uniformity of the ingot composition and structure and prevent the ingot from cracking during the forging process; Then, forging is performed at a temperature of 900° C. to 1100° C. to obtain a forging blank of a standard substance of rare metal hydrogen content; Finally, the rare metal hydrogen content standard substance forging blank is used to produce the rare metal hydrogen content standard substance wire.
10. Use of the rare metal hydrogen content standard substance as claimed in any one of claims 1 to 4 or the rare metal hydrogen content standard substance prepared by the preparation method as claimed in any one of claims 5 to 9 in the chemical analysis of zirconium and zirconium alloys, titanium and titanium alloys.