Preparation method of gradient quality control sample for trace element analysis of high-temperature alloy

Abstract

The invention discloses a preparation method of a gradient quality control sample for trace element analysis of a high-temperature alloy, and belongs to the technical field of material preparation and element analysis. Then, the gradient quality control sample for analyzing the trace elements of the high-temperature alloy is prepared through high-temperature multi-stage homogenization treatment, hot isostatic pressing treatment, rolling, uniformity inspection, constant value analysis and uncertainty evaluation, and a basis is provided for accurate and rapid analysis of the trace elements of the high-temperature alloy through a GDMS method; after the RSF is corrected by adopting a standard substance or a quality control sample matched with the high-temperature alloy matrix, the accuracy of analysis data can be improved.

Description

Technical Field

[0001] The technical field of material preparation and element analysis particularly relates to a method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy. Background Art

[0002] Nickel-based high-temperature alloys are used to manufacture hot-end components of aircraft engines and gas turbines due to their excellent high-temperature strength and corrosion resistance. The performance of high-temperature alloy products is usually closely related to the alloy composition. In addition to the main elements such as tungsten, molybdenum, aluminum, titanium and niobium, their service life is also affected by various trace elements such as lead, bismuth, tellurium, thallium, silver, tin, selenium, and arsenic. For example, in the GH4169 nickel-based high-temperature alloy with the largest usage and the widest application in aircraft engines, there are more than 20 trace elements that need to be controlled, and many of them are required to be controlled below 0.00003%. This not only places extremely high demands on the purity of the material, but also brings severe challenges to the composition analysis.

[0003] The testing of trace elements in high-temperature alloys usually adopts traditional wet methods plus instrumental analysis methods, such as atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS), inductively coupled plasma emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS), etc. These schemes require pre-treatment operations such as dissolution of the sample, but high-temperature alloys are difficult to dissolve due to the complexity of the matrix. The wasted time and large amounts of reagents also lead to high testing costs and low efficiency, which ultimately makes the analysis cost of trace elements high. Glow discharge mass spectrometry (GDMS) analysis technology can directly and quickly measure solid samples, with an element detection limit of 10 -9 The GDMS analysis method is the most effective solution for the rapid, accurate and low-cost analysis of trace elements in nickel-based high-temperature alloys.

[0004] The quantitative determination of GDMS technology adopts the relative method. The relative sensitivity factor (RSF) is obtained by using standard materials that match the matrix. The analysis accuracy is within 10%, which reaches the analysis accuracy of conventional wet methods. However, the lack of standard materials for GDMS technical analysis limits the application of the GDMS method in the field of high-temperature alloy composition analysis. The uniform distribution of dozens of trace elements in the gradient places high demands on the sample preparation process and quantitative analysis. Based on the requirements of trace element analysis of various high-temperature alloys, it is urgent to develop a set of nickel-based high-temperature alloy trace element gradient block quality control samples. Summary of the invention

[0005] The present invention proposes a method for preparing a gradient quality control sample for trace element analysis of high-temperature alloys, which is used to solve the problem of shortage of trace element high-temperature alloy quality control samples suitable for solid sampling analysis in China due to unreasonable quality control sample composition gradient design, great smelting difficulty, and time-consuming and high-cost composition uniformity detection methods.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy, comprising the following steps:

[0008] Based on the actual values ​​and standard ranges of trace elements in commonly used grades of deformed high-temperature alloys, 34 trace elements were screened out, and the upper and lower limits of each trace element were formulated as the design reference values ​​for the upper and lower limits of the target composition of the gradient quality control sample. The designed composition gradient spanned no less than two orders of magnitude. After determining the target composition and its gradient, the expected uncertainty of the gradient quality control sample was determined by the expanded uncertainty of the similar content of the corresponding elements in the commonly used grades of deformed high-temperature alloys. GH4169 alloy bars weighing no less than 800 kg were used as the raw materials for preparing the gradient quality control samples. The 34 trace elements were A g (silver), As (arsenic), Au (gold), B (boron), Ba (barium), Bi (bismuth), Ca (calcium), Cd (cadmium), Ce (cerium), Co (cobalt), Cu (copper), Ga (gallium), Ge (germanium), Hf (hafnium), In (indium), La (lanthanum), Mg (magnesium), Mn (manganese), P (phosphorus), Pb (lead), Pd (palladium), Pt (platinum), Ru (ruthenium), S (sulfur), Sb (antimony), Sc (scandium), Se (selenium), Si (silicon), Sn (tin), Ta (tantalum), Te (tellurium), Tl (thallium), Y (yttrium) and Zn (zinc);

[0009] According to the target composition of the gradient quality control sample, adding the elemental single substance or compound of the trace element component to the raw material composition through vacuum induction melting;

[0010] After the vacuum induction melting is completed, an ingot is obtained, and a high-temperature multi-stage homogenization treatment is performed on the ingot. The high-temperature multi-stage homogenization treatment is as follows: first, the temperature is raised to 1120-1140°C at a rate of 5-10°C / min, and the temperature is kept for 5-15h, then the temperature is raised to 1150-1170°C at a rate of 1-5°C / min, and the temperature is kept for 20-40h, and finally the temperature is raised to 1180-1200°C at a rate of 1-5°C / min, and the temperature is kept for 40-70h. Since the matrix of the gradient quality control sample is GH4169 alloy, the Nb content in the alloy is relatively high and is easy to segregate. Secondly, the alloy is also Contains a large amount of trace elements, the content of many trace elements exceeds the limit range of the alloy, and the diffusion rate of some elements with relatively high atomic numbers is slow, and the quality control sample has high requirements for the uniformity and consistency of the composition. Therefore, the present invention uses a high-temperature multi-stage homogenization treatment method to reduce the segregation of Nb elements and the uniform diffusion of high-content trace elements. The slow rate heating and heat preservation between 1120°C and 1170°C is to eliminate the low-melting point Laves phase and reduce the influence of Nb element segregation on the uniformity of the chemical composition of the alloy; the long-term heat preservation at 1180~1200°C is to achieve uniform distribution of trace elements;

[0011] Performing hot isostatic pressing on the ingot after the high-temperature multi-stage homogenization treatment;

[0012] The ingot after hot isostatic pressing is prepared into a round rod by blanking, the round rod is surface processed, and the head and tail of the round rod after surface processing are tested for composition to ensure the successful addition of the added trace element and the content of the trace element presents a designed gradient distribution. When the success rate of the added trace element is not less than 85%, the gradient quality control sample is processed, uniformity tested, fixed value analyzed and uncertainty evaluated;

[0013] The feasibility of the gradient quality control sample is evaluated by comparison and verification, and the comparison and verification includes linearity inspection and consistency inspection. When the correlation coefficients of the linearity inspection and the consistency inspection are not less than 0.99, the gradient quality control sample for trace element analysis of the high-temperature alloy is prepared.

[0014] Commonly used grades of the deformed high-temperature alloy are GH4169 alloy, GH4169D alloy, GH4720Li alloy, GH4065A alloy, GH4738 alloy, FGH4096 alloy, DD405 alloy and DD406 alloy.

[0015] The vacuum induction melting includes: processing the GH4169 alloy rod into a block raw material with a weight of not less than 100 kg, adding the block raw material into a vacuum induction melting furnace, evacuating the vacuum induction melting furnace to a vacuum degree not higher than 5 Pa, heating the vacuum induction melting furnace until the block raw material is completely melted, introducing argon gas, adding the element single substance or compound of the trace element component according to the target composition of the gradient quality control sample, refining time not exceeding 30 minutes, taking out of the furnace and pouring to obtain an ingot.

[0016] During the hot isostatic pressing treatment, the heating rate is 0.1-5°C / min, the temperature is 1150-1200°C, the pressure is 140MPa-180MPa, the temperature and pressure are kept for 2-4h, and the furnace is cooled with argon gas.

[0017] The step of preparing the round rod by opening the ingot after the hot isostatic pressing treatment is as follows: heating the ingot to 1060-1100°C at a rate of 2-5°C / min, keeping the temperature for 4 hours, and upsetting by 20-30%; then returning the ingot to the furnace for keeping the temperature for 4 hours, and unidirectionally stretching the ingot with a deformation of 20-40%; returning the ingot to the furnace for keeping the temperature again, keeping the temperature at 1040-1080°C, and continuing the unidirectional stretching with a deformation of 20-40%, and repeating the unidirectional stretching process 1-3 times to obtain the round rod. 32mm round rod.

[0018] The fixed value analysis adopts multi-laboratory and multi-method joint fixed value, and according to JJF 1343-2022 "Value Determination and Uniformity and Stability Evaluation of Reference Materials", the average of the average values ​​of the fixed value data of the characteristic quantity of each laboratory is used as the certified value of the characteristic quantity.

[0019] The uncertainty is the combined standard uncertainty, which is calculated in accordance with JJF 1343-2012 "General Principles and Statistical Principles for the Determination of Reference Materials", as shown in formula (1):

[0020] (1)

[0021] In formula (1), is the combined standard uncertainty, The standard uncertainty brought by the determination process, is the standard uncertainty due to the inhomogeneity between bottles, is the standard uncertainty due to long-term instability, is the standard uncertainty due to short-term instability;

[0022] The standard uncertainty caused by the determination process is A-rated weight (i.e., Type A uncertainty) and Type B assessment components (i.e., Type B uncertainty) synthesis, see formula (2) for details:

[0023] (2)

[0024] Class B uncertainty involves the influence of non-statistical factors in the measurement process, such as instrument calibration, changes in the measurement environment, etc. In the case of multiple accurate methods jointly determining the value, these non-statistical factors have been reflected in the observations of each laboratory, so the Class B uncertainty is no longer calculated separately in the determination process. In the preparation process of the gradient quality control sample for trace element analysis of high-temperature alloys of the present invention, the laboratory determination data was tested for normality, and the test data that caused the normality test to be non-normally distributed was eliminated. When the overall normality of the determination data is good, the Class A uncertainty is calculated by formula (3):

[0025] (3)

[0026] In formula (3), is the standard deviation in the setting process, is the number of data sets;

[0027] The rounding off of the standard value data of the gradient quality control samples follows the rounding off rule for uncertainty in GB 8170-2008 “Rules for numerical rounding off and expression and determination of limit values” and adopts the principle of only increasing and not decreasing.

[0028] Compared with the prior art, the present invention has the following advantages and technical effects:

[0029] (1) The present invention successfully prepared a gradient quality control sample for trace element analysis of high-temperature alloys. 31 elements were successfully added and distributed in a gradient, meeting the requirements of target composition design, and providing a reference for the subsequent preparation of high-temperature alloys and other quality control samples. The route of the present invention is simple and low-cost, and can achieve large-scale manufacturing of quality control samples, effectively reducing the cost of component analysis.

[0030] (2) The gradient quality control sample for trace element analysis of high-temperature alloys prepared by the present invention provides a basis for accurate and rapid analysis of trace elements in high-temperature alloys by the GDMS method. The GDMS analysis method can improve the accuracy of the analysis data after the RSF is corrected by using standard materials or quality control samples that match the high-temperature alloy matrix. The present invention solves the problem of the lack of high-temperature alloy standard materials for the GDMS analysis method in my country, fills the gap in this field in China, and has great significance in the production control of high-temperature alloy products, finished product analysis, and test equipment measurement.

[0031] (3) The present invention lays a foundation for the application of rapid analysis technology of trace elements in high-temperature alloys. By combining gradient quality control samples with the GDMS method, the analysis cycle of traditional chemical wet methods and instrumental analysis methods can be shortened from 15 working days to less than 1 working day, and the cost can be reduced by about 90%. It provides technical support for low-cost, rapid and accurate analysis of high-temperature alloy materials, serves the preparation of my country's high-end equipment and ensures its service safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 This is a schematic diagram of the process of preparing quality control samples for trace element analysis of high-temperature alloys according to the present invention;

[0034] Figure 2 This is a physical picture of the ingot after rolling in Comparative Example 1. DETAILED DESCRIPTION

[0035] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0036] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0037] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0038] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0039] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0040] An embodiment of the present invention provides a method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy, comprising the following steps:

[0041] (1) Composition gradient design of gradient quality control samples for trace element analysis of high-temperature alloys: The present invention uses the actual values ​​and standard ranges of trace elements in the most commonly used grades of deformed high-temperature alloys in my country (GH4169 alloy, GH4169D alloy, GH4720Li alloy, GH4065A alloy, GH4738 alloy, FGH4096 alloy, DD405 alloy and DD406 alloy) to screen out 34 trace elements as the object. The 34 trace elements are Ag, As, Au, B, Ba, Bi, Ca, Cd, Ce, Co, Cu, Ga, Ge, Hf, In, La, Mg, Mn, P, Pb, Pd, Pt, Ru, S, Sb, Sc, Se, Si, Sn, Ta, Te, Tl, Y and Zn. Following the principle of meeting wider analysis requirements with fewer sample points, we strive to cover the composition requirements of high-temperature alloy grades with one set or fewer sample points. Based on the principle of improving compatibility, we formulate the upper and lower limits of each trace element as the design reference values ​​for the upper and lower limits of the target composition of the gradient quality control sample. The designed composition gradient spans no less than two orders of magnitude. After determining the target composition and its gradient, the expected uncertainty of the gradient quality control sample is determined by the expanded uncertainty of the similar content of the corresponding elements in steel and alloys. Based on high purity, low cost and output, the GH4169 alloy prepared by triple smelting is selected as the master alloy. After testing the composition of 50 batches of GH4169 alloy, it is finally determined that GH4169 alloy bars weighing no less than 800kg are used as the raw materials for the preparation of gradient quality control samples.

[0042] (2) According to the target composition of the gradient quality control sample, on the basis of the raw material composition of GH4169 alloy, the elemental single metal or compound of the trace element composition is added by vacuum induction melting, that is, after the raw materials and the elemental single metal or compound to be added are prepared, the vacuum induction melting method is used for remelting to achieve the preparation of the target alloy ingot, specifically: first, the GH4169 alloy bar is cut into block raw materials with a weight of not less than 100kg (preferably the weight of the block raw materials is 100kg~500kg), and then added into a vacuum induction melting furnace, evacuated to a vacuum degree of not more than 5Pa, heated to between 1300℃ and 1400℃ to ensure that the alloy is completely melted, and then argon (Ar gas) not higher than 0.1MPa is introduced, and the target trace element is added to make the component ratio weight reach the alloy target value, the refining time does not exceed 30min, and then the ingot containing different trace elements is cast out of the furnace;

[0043] (3) The ingots containing different trace elements were subjected to homogenization treatment: the temperature was raised to 1120~1140℃ at a rate of 5~10℃ / min, and kept at this temperature for 5~15h, then the temperature was raised to 1150℃~1170℃ at a rate of 1~5℃ / min, and kept at this temperature for 20~40h, and finally the temperature was raised to 1180~1200℃ at a rate of 1~5℃ / min, and kept at this temperature for 40~70h. Since the matrix of the gradient quality control sample is GH4169 alloy, the Nb content in the alloy is high and easy to segregate. Secondly, the alloy also contains a large number of trace elements, and the content of many trace elements exceeds the limit range of the alloy. In addition, the diffusion rate of some elements with relatively high atomic numbers is slow. The quality control sample has high requirements for the uniformity and consistency of the composition. The high-temperature multi-stage homogenization method is used to reduce the segregation of the Nb element and the uniform diffusion of high-content trace elements. The slow rate heating and heat preservation between 1120℃~1170℃ is to eliminate the low-melting point Laves phase and reduce the influence of Nb element segregation on the uniformity of the chemical composition of the alloy; the long-term heat preservation at 1180~1200℃ is to achieve uniform distribution of trace elements.

[0044] (4) The ingot after homogenization treatment is subjected to hot isostatic pressing treatment: heating rate 0.1~5℃ / min, temperature 1150~1200℃, pressure 140MPa~180Mpa, heat and pressure maintenance for 2~4h, and cooling with Ar gas. The ingot after vacuum induction melting has shrinkage holes at the head and local microcracks inside. Some trace elements are easy to segregate at the grain boundary, resulting in grain boundary weakening, and high-temperature plasticity is seriously reduced. Direct thermal deformation will cause cracking. Therefore, hot isostatic pressing treatment effectively reduces the microcracks inside the ingot and further improves the thermoplasticity.

[0045] (5) The ingot is prepared into a round bar by opening the blank, and the ingot after hot isostatic pressing is heated to 1060~1100℃ at a rate of 2~5℃ / min, kept at this temperature for 4h, and then upset by 20~30%; then it is returned to the furnace for keeping at this temperature for 4h, and unidirectionally stretched with a deformation of 20%~40%; after returning to the furnace for keeping at this temperature again, the holding temperature is 1040~1080℃, and unidirectionally stretched with a deformation of 20%~40% is continued. By repeating the unidirectional stretching process 1~3 times, a round bar is obtained. 32mm round bar;

[0046] (6) Yes The 32mm round bar is surface processed to remove the black skin on the surface and the metallic luster is visible. 30mm round rods are used for subsequent gradient quality control sample processing;

[0047] (7) Select small-sized rolled bars (i.e. 30mm round rod) to ensure the successful addition of various trace elements and the content presents the designed gradient distribution. When the success rate of added trace elements is not less than 85%, subsequent gradient quality control sample processing and uniformity inspection are carried out;

[0048] (8) The rolled small-size bars are cut in 30 mm lengths to obtain The cylindrical samples of 30mm×30mm are the spectral quality control samples, and are marked in order as 1-1, 1-2, 1-3, 1-4, 1-5, etc. The first number is the code of the five samples, arranged from low to high in terms of composition, and the last number is the order in which the samples of a certain component are cut. Ten samples of each sample are randomly selected and processed into chip-like samples using a milling machine, fully mixed, and packaged into 50g / bottles. The components of each element are accurately determined by traditional wet methods and instrumental analysis methods in several laboratories with inspection qualifications;

[0049] (9) Conduct uniformity test. The uniformity test of this batch of quality control samples shall be sampled in accordance with JJF1342-2022 "General Requirements for Research and Development (Production) Organizations of Reference Materials"; data shall be processed in accordance with JJF 1343-2012 "General Principles and Statistical Principles for the Determination of the Value of Reference Materials";

[0050] (10) Perform fixed value analysis and uncertainty assessment on quality control samples:

[0051] In the present invention, the quality control samples have many elements with low element content, and the determination of values ​​is difficult. Multi-laboratory and multi-method joint determination is adopted. According to JJF 1343-2022 "Value Determination and Uniformity and Stability Evaluation of Standard Materials", the mean of the average values ​​of the characteristic quantity determination data of each laboratory is used as the recognition value of the characteristic quantity.

[0052] Referring to JJF 1343-2012 "General Principles and Statistical Principles for the Determination of Standard Materials", JJF 1343-2012 "General Principles and Statistical Principles for the Determination of Standard Materials" specifies in detail the evaluation method of the uncertainty of standard materials. The specification points out that the uncertainty of standard materials consists of three parts: the uncertainty introduced by uniformity, the uncertainty introduced by stability, and the uncertainty caused by the determination process. The combined standard uncertainty is obtained by calculating the square root of the sum of the squares of these three parts, and finally multiplying it by the inclusion factor k to obtain the expanded uncertainty, where k is usually 2, corresponding to a 95% confidence probability of 2. The basic calculation formula for the combined standard uncertainty is detailed in formula (1):

[0053] (1)

[0054] In formula (1), is the combined standard uncertainty, The standard uncertainty brought by the determination process, is the standard uncertainty due to the inhomogeneity between bottles, is the standard uncertainty due to long-term instability, is the standard uncertainty due to short-term instability;

[0055] Standard uncertainty caused by the determination process A-rated weight (i.e., Type A uncertainty) and Type B assessment components (i.e. Class B uncertainty) synthesis. The assessment of Class B and Class A uncertainties comes from JJF 1059.1-2012 "Evaluation and Expression of Uncertainty in Measurement", referred to as the GUM method, which can also be called the Bottom-up method. It is the measurement uncertainty assessment method currently used in various industries internationally. Class B uncertainty refers to the uncertainty component evaluated by non-statistical methods, which is usually evaluated based on experience, information or assumed probability distribution. First, it is necessary to identify the source of uncertainty, which includes factors such as the metrological performance of the measuring instrument, the influence of environmental conditions, and the accuracy of the measurement model. Based on relevant information or experience, the possible value range of the measured value is judged, and the probability distribution of the measured value is assumed. On this basis, the inclusion factor k is determined according to the probability distribution and the required inclusion probability p, thereby calculating the Class B standard uncertainty. The calculation method of is shown in formula (2):

[0056] (2)

[0057] Class B uncertainty involves the influence of non-statistical factors in the measurement process, such as instrument calibration, changes in the measurement environment, etc. In the case of multiple accurate methods jointly determining the value, these non-statistical factors have been reflected in the observations of each laboratory, so the Class B uncertainty is no longer calculated separately in the determination process. In the preparation process of the gradient quality control sample for trace element analysis of high-temperature alloys of the present invention, the laboratory determination data was tested for normality, and the test data that caused the normality test to be non-normally distributed was eliminated. When the overall normality of the determination data is good, the Class A uncertainty is calculated by formula (3):

[0058] (3)

[0059] In formula (3), is the standard deviation in the setting process, is the number of data sets.

[0060] The rounding off of the standard value data of trace elements in the gradient quality control samples used for trace element analysis of high-temperature alloys follows the rounding off rule of uncertainty in GB8170-2008 "Rules for numerical rounding off and expression and determination of limit values" and adopts the principle of only improving and not reducing.

[0061] (11) The feasibility of preparing gradient trace element quality control samples for high-temperature alloys was evaluated by comparative verification (including linearity test and consistency test). When the correlation coefficients of linearity test and consistency test were not less than 0.99, the gradient quality control samples passed the finished product uniformity test, uniformity test and comparative verification in turn, and the gradient quality control samples were successfully prepared.

[0062] In the following embodiments of the present invention, 34 trace elements are added in the following forms: silver, arsenic, gold, barium, bismuth, cadmium, gallium, germanium, hafnium, indium, lead, palladium, platinum, ruthenium, antimony, scandium, selenium, tin, tellurium, thallium, zinc, copper, cobalt and tantalum are added in the form of elemental metals; silicon, chromium, manganese, boron, phosphorus and sulfur are added in the form of ferrosilicon, ferrochromium nitride, ferromanganese, ferroboron, ferrophosphorus and ferrosulfur, respectively; calcium, lanthanum, cerium and yttrium are added in the form of calcium oxide, lanthanum oxide, cerium oxide and yttrium oxide, respectively.

[0063] In the following examples of the present invention, standard samples GBW01636-GBW01640 were purchased from China Steel Research Institute NAK Testing Technology Co., Ltd.

[0064] In the following embodiments of the present invention, information values ​​refer to those characteristic values ​​that have certain use value to the users of the reference material, but these values ​​lack sufficient information in terms of uncertainty assessment. Information values ​​are usually not regarded as traceable or rigorously measured values, but are provided to users more as reference information to help users understand the matrix composition of the reference material or judge its applicability.

[0065] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in the art and are not the focus of the present invention.

[0066] The technical solution of the present invention is further illustrated by the following embodiments.

[0067] Example 1

[0068] The composition points are designed by referring to the standard regulations of other commonly used grades of deformed high-temperature alloys (GH4169 alloy, GH4169D alloy, GH4720Li alloy, GH4065A alloy, GH4738 alloy, FGH4096 alloy, DD405 alloy and DD406 alloy). For example, the composition requirement of trace element Ag in deformed and powder high-temperature alloys is ≤0.0005%, and the composition requirement of single crystal high-temperature alloys is <0.0001%, so the composition design for Ag is 0.00001%, 0.0005%, 0.0001%, and 0.0002%, and the expected uncertainties are 0.00001%, 0.00003%, 0.00005%, and 0.00007% respectively; the composition requirement of As in deformed high-temperature alloys is ≤0.0025%, and the composition requirement of single crystal high-temperature alloys is The requirement for the composition of Au in single crystal high temperature alloy is ≤0.001%, the composition design is 0.0007%, 0.0010%, 0.0020%, 0.0040%, and the expected uncertainties are 0.0003%, 0.0003%, 0.0004%, 0.0007%, respectively; the requirement for the composition of Au in single crystal high temperature alloy is <0.000005%, the composition design is 0.00005%, 0.0001%, 0.0002%, 0.0005%, and the expected uncertainties are 0.00003%, 0.000 05%, 0.00008%, 0.0002%; the composition requirement of La in single crystal high temperature alloy is 0.00007%, and the composition design is 0.00001%, 0.00005%, 0.0001%, 0.0002%, and the expected uncertainty is 0.00001%, 0.00003%, 0.00005%, 0.00007%; the composition requirement of Ce in single crystal high temperature alloy is <0.0001%, and the composition design is 0.00001%, 0.00005% , 0.0001%, 0.0002%, and the expected uncertainties are 0.00001%, 0.00003%, 0.00005%, 0.00007%, respectively; the composition requirement of matrix elements such as Cu in deformed high-temperature alloys is ≤0.3%, and the composition requirement of single-crystal high-temperature alloys is ≤0.1%, and the composition design is 0.0039%, 0.010%, 0.020%, 0.050%, and the expected uncertainties are 0.001%, 0.002%, 0.004%, 0.005%, etc. The target values, composition gradient design and uncertainty of 34 trace elements in 5 samples are shown in Tables 1 and 2. Sample No. 1 is a GH4169 alloy without any additional elements, so it is not reflected in Tables 1 and 2. Samples No. 2 to 4 are gradient quality control samples for trace element analysis of high-temperature alloys of the present invention with different gradients.

[0069] Table 1 Design of standard material composition (mass fraction (×10 -2 )

[0070]

[0071] Table 2 Design of standard material composition (mass fraction (×10 -2 )

[0072]

[0073] (2) Cut GH4169 alloy bars weighing not less than 800 kg into blocks weighing 120 kg and add them into a vacuum induction melting furnace as raw materials. The vacuum induction melting furnace is evacuated to less than 5 Pa and heated to 1340 ° C to ensure that the alloy is completely melted. Ar gas is introduced to 0.06 MPa, and target trace elements (single substance or compound) are added to make the component ratio weight reach the target value of the alloy. The alloy is fully heated and stirred, and poured after 20 minutes of refining. After the pouring is completed, wait for 20 minutes before taking it out of the furnace to obtain alloys containing different trace elements. 200mm ingot.

[0074] (3) The temperature was raised to 1130°C at a rate of 10°C / min, and kept at this temperature for 10 hours. Then, the temperature was raised to 1160°C at a rate of 5°C / min, and kept at this temperature for 30 hours. Finally, the temperature was raised to 1190°C at a rate of 2°C / min, and kept at this temperature for 50 hours. After being taken out of the furnace, the ingot was further subjected to hot isostatic pressing treatment at a heating rate of 2°C / min, and maintained at 1190°C and 150MPa for 3 hours. The ingot was cooled by cooling with Ar gas, and then air-cooled after being taken out of the furnace.

[0075] (4) The ingot after hot isostatic pressing was heated to 1080°C at a rate of 3°C / min, kept at this temperature for 4 hours, and then upset by 25%. Then, the ingot was returned to the furnace for keeping at this temperature for 4 hours, and then unidirectionally stretched with a deformation of 30%. After being returned to the furnace for keeping at this temperature again, the ingot was kept at this temperature at 1060°C, and then unidirectionally stretched with a deformation of 35%. By repeating the unidirectional stretching process twice, the ingot was obtained. 32mm round rod, the round rod is polished to remove the black skin on the surface and the metallic luster is visible, 30mm round rod.

[0076] (5) Take one rolled sample each ( 30mm round bars), finished product inspection was carried out using the GDMS method, and the results are shown in Tables 3 and 4.

[0077] Table 3 Finished product inspection (mass fraction (×10 -2 )

[0078]

[0079] Table 4 Finished product inspection (mass fraction (×10 -2 )

[0080]

[0081] The results of Tables 3 and 4 show that the Ba element was not successfully added, the Cd and Sc elements were only added at high points, and the other elements basically met the addition requirements. The success rate of the added target elements was 91%, and the success rate exceeded 85%, proving that the preparation process of the present invention is reasonable and feasible.

[0082] (6) Take samples from the five samples at intervals of 20 cm to obtain 12 block samples respectively, and measure them in the following order (three tests each). Repeat measurement 1: 1-3-5-7-9-11-2-4-6-8-10-12; Repeat measurement 2: 12-11-10-9-8-7-6-5-4-3-2-1; Repeat measurement 3: 2-4-6-8-10-12--1-3-5-7-9-11.

[0083] The GDMS method was used to study the homogeneity of 34 trace elements. A complete GDMS analysis method was established by optimizing the glow discharge conditions (discharge current 40mA, discharge gas flow 450mL / min, pre-sputtering time 10min), studying isotope interference, correcting RSF factors, etc., and the uniformity detection data was obtained using the optimized method.

[0084] The F statistic and F critical value of comparative variance analysis were used for the uniformity results. The uniformity test results showed that the fixed elements of the quality control samples had good uniformity (the F statistic was less than the F critical value), which met the uniformity requirements of the quality control samples.

[0085] (7) The values ​​were determined by 10 laboratories with testing capabilities and qualifications. The trace element values ​​were determined by ICP-MS and ICP-AES. The normality test, outlier test and equal precision test were performed on the valued data to obtain valid data.

[0086] (8) Determine the uncertainty of quality control samples. In the process of developing gradient quality control samples for trace element analysis of high-temperature alloys: multiple laboratories are used to determine the value, and each element is determined by two or more methods, and Class B uncertainty is no longer considered. is the standard uncertainty caused by the non-uniformity between bottles. The uncertainty caused by uniformity includes the uncertainty between units and the uncertainty within units. In the present invention, when the F value is greater than 1, is the uncertainty between units s bb ; When F﹤1, Estimated by the variance of the inhomogeneity within the unit. In the stability study, the chemical properties of the high-temperature alloy are very stable, so the effect of stability can be ignored. The expanded uncertainty U is calculated according to Calculate, where is the inclusion factor. When the confidence probability is 95%, k=2.

[0087] (9) The gradient quality control samples have passed the composition design, sample development, finished product inspection, uniformity inspection, and comparison test in sequence, proving that they have been successfully developed. The certified values ​​(X) and expanded uncertainties (U) of the gradient quality control samples for trace element analysis of high-temperature alloys are shown in Tables 5 and 6.

[0088] Table 5 Certification values ​​and expanded uncertainties (mass fraction (×10 -6 )

[0089]

[0090] Table 6 Certification values ​​and expanded uncertainties (mass fraction (×10 -6 )

[0091]

[0092] Note: In Table 5 and Table 6, “X” is the certified value and “U” is the expanded uncertainty ( =2), the values ​​in “()” are reference values, and the values ​​with “#” are information values.

[0093] Example 2

[0094] Same as Example 1, except that in step (6), in addition to the F statistic test, the total standard deviation S and the heterogeneity variance S are also examined in the uniformity study. 2 bb Whether it meets the actual needs, a supplementary uniformity evaluation is conducted on the simple F test. The specific method is as follows:

[0095] (1) Compared with the uncertainty associated with the fixed value, the standard deviation between units and / or within units is smaller, such as ;

[0096] (2) Allowing for material inhomogeneity, calculate the combined standard uncertainty of the standard value , and confirm that it is acceptable for its intended use;

[0097] (3) For those who do not calculate the combined standard uncertainty Standard deviations of inter-laboratory reproducibility typical for the application area, such as quality control standards By comparison, the standard deviation between units is small enough, ideally, ;

[0098] The uniformity test results of other methods show that the trace elements of the gradient quality control sample of the present invention still have good uniformity and meet the actual needs.

[0099] Example 3

[0100] The same as Example 1, except that, in step (6), in order to save time, when using glow mass spectrometry to detect the uniformity of the sample, the pre-sputtering time is set to 5 minutes, and the other conditions remain the same.

[0101] The experimental results show that within 5 to 10 minutes of the start of discharge, the intensity of the interfering element Ca is unstable and shows a trend from high to low, which cannot meet the normal test requirements. However, after 10 minutes, the intensity of Ca tends to be stable, indicating that the pollution caused by it can be completely removed at least after 10 minutes. At this time, the strength of the matrix Ni also changes slowly, which meets the test requirements.

[0102] GDMS was used to fit the 30 trace elements and 5 content level gradients of the gradient quality control sample for trace element analysis of the high-temperature alloy prepared in this embodiment, and it was found that the fitting results were linear. The results show that the 5-point standard curve has a very good linear relationship, and the correlation coefficients are all greater than 0.995. At the same time, the gradient quality control sample for trace element analysis of the high-temperature alloy prepared in this embodiment was curve-fitted with the 16 elements of the nickel-based deformed high-temperature alloy standard material (standard sample) GBW01636~GBW01640 developed in 2002. The 10-point standard curve has a very good linear relationship, and the correlation coefficients are all greater than 0.998, indicating that the consistency of the two sets of standard materials is good. Through comparison experiments, it is proved that the present invention successfully prepared gradient quality control samples.

[0103] Comparative Example 1

[0104] The same as Example 1, except that in step (3), the hot isostatic pressing step is omitted to save time and energy consumption, and the subsequent effect is observed.

[0105] Results: The ingot of this comparative example exhibited severe cracking during the rolling process of step (4) (see Figure 2 ), it is speculated that due to the presence of shrinkage holes at the head of the vacuum induction melted ingot and local microcracks inside, some trace elements are prone to segregation at the grain boundaries, resulting in grain boundary weakening, a serious decrease in high temperature plasticity, and direct thermal deformation leading to the occurrence of cracking.

[0106] Application Example 1

[0107] Taking the gradient quality control sample prepared in Example 1 as an example, by combining the gradient quality control sample with the GDMS method, a relatively complete set of analysis methods for trace impurity elements in high-temperature alloys by glow discharge mass spectrometry was established in the optimization of glow discharge conditions, the study of isotope interference, and the correction of RSF factors. The stability of similar nickel-based high-temperature alloy component analysis standard materials numbered GBW01636 to GBW0640 was monitored within 8 hours. The measured elements were 20 trace elements such as Ag, As, B, and Bi. The standard values ​​of the elements did not change significantly. The monitoring results are shown in Tables 7 and 8. The specific method is:

[0108] According to JJF 1343-2022 "Value determination and uniformity and stability evaluation of reference materials", if the conditions are met: Then it can be considered that the material is sufficiently stable and the stability has been proven. Indicates the characteristic value of CRM, is the observed value of the measurement, k is the coverage factor, and k=2 when the confidence level is 95%. The standard uncertainty due to the measurement, Standard uncertainty of the characteristic value.

[0109] According to the expanded uncertainty definition: ,because is a non-negative value, it can be proved that in this stability monitoring, if If established, The stability is thus proved.

[0110] Table 7 Summary of stability monitoring results of GBW01636 to GBW01640 in January 2022 (μg / g)

[0111]

[0112] Table 8 Summary of stability monitoring results of GBW01636 to GBW01640 in January 2022 (μg / g)

[0113]

[0114] The above results show that the use of the GDMS method for stability monitoring shortens the analysis cycle of traditional chemical wet methods and instrumental analysis methods from 15 working days to less than 1 working day. The GDMS method mainly relies on the same type of standard substances and detection instruments, and does not require the use of additional chemical reagents, reducing the detection cost by about 90% (from more than 20,000 yuan to about 2,000 yuan).

[0115] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy, characterized in that: The following steps are involved: Based on the actual values ​​and standard ranges of trace elements in commonly used grades of deformed high-temperature alloys, 34 trace elements were screened out, and the upper and lower limits of each trace element were formulated as the design reference values ​​for the upper and lower limits of the target composition of the gradient quality control sample. The designed composition gradient spanned no less than two orders of magnitude; after determining the target composition and its gradient, the expected uncertainty of the gradient quality control sample was determined by the expanded uncertainty of the similar content of the corresponding elements in the commonly used grades of deformed high-temperature alloys; A GH4169 alloy rod weighing not less than 800 kg is used as a raw material for preparing the gradient quality control sample, and the 34 trace elements are Ag, As, Au, B, Ba, Bi, Ca, Cd, Ce, Co, Cu, Ga, Ge, Hf, In, La, Mg, Mn, P, Pb, Pd, Pt, Ru, S, Sb, Sc, Se, Si, Sn, Ta, Te, Tl, Y and Zn; According to the target composition of the gradient quality control sample, adding the elemental single substance or compound of the trace element component to the raw material composition through vacuum induction melting; After the vacuum induction melting is completed, an ingot is obtained, and the ingot is subjected to a high-temperature multi-stage homogenization treatment, wherein the high-temperature multi-stage homogenization treatment is as follows: firstly, the temperature is increased to 1120-1140°C at a rate of 5-10°C / min, and the temperature is kept for 5-15 hours, then the temperature is increased to 1150-1170°C at a rate of 1-5°C / min, and the temperature is kept for 20-40 hours, and finally, the temperature is increased to 1180-1200°C at a rate of 1-5°C / min, and the temperature is kept for 40-70 hours; Performing hot isostatic pressing on the ingot after the high-temperature multi-stage homogenization treatment; The ingot after hot isostatic pressing is prepared into a round rod by blanking, the round rod is surface processed, and the head and tail of the round rod after surface processing are tested for composition to ensure the successful addition of the added trace element and the content of the trace element presents a designed gradient distribution. When the success rate of the added trace element is not less than 85%, the gradient quality control sample is processed, uniformity tested, fixed value analyzed and uncertainty evaluated; The feasibility of the gradient quality control sample is evaluated by comparison and verification, and the comparison and verification includes linearity inspection and consistency inspection. When the correlation coefficients of the linearity inspection and the consistency inspection are not less than 0.99, the gradient quality control sample for trace element analysis of the high-temperature alloy is prepared.

2. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: The commonly used grades of deformed high-temperature alloys are GH4169 alloy, GH4169D alloy, GH4720Li alloy, GH4065A alloy, GH4738 alloy, FGH4096 alloy, DD405 alloy and DD406 alloy.

3. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: The vacuum induction melting includes: processing the GH4169 alloy rod into a block raw material with a weight of not less than 100 kg, adding the block raw material into a vacuum induction melting furnace, evacuating the vacuum induction melting furnace to a vacuum degree not higher than 5 Pa, heating the vacuum induction melting furnace until the block raw material is completely melted, introducing argon gas, adding the element single substance or compound of the trace element component according to the target composition of the gradient quality control sample, refining time not exceeding 30 minutes, taking out of the furnace and pouring to obtain an ingot.

4. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: During the hot isostatic pressing treatment, the heating rate is 0.1-5°C / min, the temperature is 1150-1200°C, the pressure is 140MPa-180MPa, the temperature and pressure are kept for 2-4h, and the furnace is cooled with argon gas.

5. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: The step of preparing the round rod by opening the ingot after the hot isostatic pressing treatment is as follows: heating the ingot to 1060-1100°C at a rate of 2-5°C / min, keeping the temperature for 4 hours, and upsetting by 20-30%; then returning the ingot to the furnace for keeping the temperature for 4 hours, and unidirectionally stretching the ingot with a deformation of 20-40%; returning the ingot to the furnace for keeping the temperature again, keeping the temperature at 1040-1080°C, and continuing the unidirectional stretching with a deformation of 20-40%, and repeating the unidirectional stretching process 1-3 times to obtain the round rod. 32mm round rod.

6. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: The fixed value analysis adopts multi-laboratory and multi-method joint fixed value, and according to JJF 1343-2022 "Value Determination and Uniformity and Stability Evaluation of Reference Materials", the average of the average values ​​of the fixed value data of the characteristic quantity of each laboratory is used as the certified value of the characteristic quantity.

7. The method for preparing a gradient quality control sample for trace element analysis of a high-temperature alloy according to claim 1, characterized in that: The uncertainty is the combined standard uncertainty. The calculation formula of the combined standard uncertainty is shown in formula (1): （1） In formula (1), is the combined standard uncertainty, The standard uncertainty brought by the determination process, is the standard uncertainty due to the inhomogeneity between bottles, is the standard uncertainty due to long-term instability, is the standard uncertainty due to short-term instability; The standard uncertainty caused by the determination process is A-rated weight and B-level rating Synthesis, see formula (2): （2） When the overall normality of the fixed value data is good, the type A uncertainty is calculated by formula (3): （3） In formula (3), is the standard deviation in the setting process, is the number of data sets.

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