Sample dissolving method of nickel-based alloy

Abstract

The invention provides a sample dissolving method of a nickel-based alloy, and belongs to the technical field of analytical chemistry, and the nickel-based alloy comprises the following components in percentage by mass: 0.15-0.20% of C, 0.15-0.20% of B, 0.15-0.20% of C, and the balance of Fe and inevitable impurities. Comprising the following steps: preliminarily dissolving a sample through concentrated hydrochloric acid and concentrated nitric acid; adding perchloric acid, and preserving heat for 1-2 minutes at the temperature of 100-120 DEG C to obtain a yellow insoluble substance, the ratio of the adding volume of the perchloric acid to the mass of the sample being (110-130) mL: 1g; transferring the liquid and the yellow insoluble substance into a second reaction cup, adding hydrofluoric acid, and keeping the temperature at 50-60 DEG C for 2-4 minutes; and fixing the volume after dissolving. Firstly, concentrated hydrochloric acid and concentrated nitric acid are adopted for dissolution, due to the fact that the content of Cr, Mo and W is high, and detection of Ce, Si and other metals cannot be affected, the adding mode of the concentrated nitric acid and the concentrated hydrochloric acid is limited, then perchloric acid is added, fuming of the perchloric acid is controlled, and the content of the perchloric acid and the content of the concentrated nitric acid which are added in the earlier stage are combined; the method has the advantages that low Cr content due to generation of CrO2Cl2 is avoided while metal carbides are dissolved, undissolved yellow substances are dissolved in combination with hydrofluoric acid, and low Si content due to generation of SiF4 is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of analytical chemistry, and in particular relates to a method for dissolving a nickel-based alloy sample. Background Art

[0002] Superalloys are key materials for hot-end components in aviation engines and various high-temperature components in space rocket engines. They also provide high-temperature, corrosion-resistant components required by industrial gas turbines, energy, and chemical industries, making them essential to the national economy. Superalloys are categorized by elemental composition into nickel-based, iron-based, and cobalt-based types. Nickel-based superalloys are the most widely used, accounting for 80% of the total.

[0003] Nickel-based alloys are high-temperature alloys used in high-end manufacturing fields such as aerospace. They contain numerous alloying elements, and their nickel matrix has a face-centered cubic lattice structure, which allows them to accommodate more alloying elements than iron-based alloys. Due to their excellent corrosion resistance and high-temperature strength, they are widely used in high-end manufacturing fields such as aerospace, marine, and shipbuilding. The chemical composition has a crucial impact on the various properties of these alloys, making accurate analysis of their composition particularly important. Currently, the main analytical methods include spectrophotometry, flame atomic absorption spectrometry, and gravimetric methods. However, these methods are complex and can only determine single elements, resulting in low efficiency. Arc emission spectrometry can determine impurity elements in nickel-based alloys, but this method requires dissolving and evaporating the sample, grinding it into a powder, and measuring it on an arc emission spectrometer. This is a cumbersome process and requires the purchase of equipment, making it equally undesirable.

[0004] Inductively coupled plasma optical emission spectrometry (ICP-AES) is widely used due to its advantages, including the ability to simultaneously determine multiple elements, low detection limits, a wide linear range, and high sensitivity. However, for samples high in Cr, Mo, W, and C, as well as for simultaneous measurement of Si and Ce, the existing technology lacks a specific dissolution method that can accurately measure these elements simultaneously. Multiple dissolution methods are typically used, such as dividing the sample into multiple portions, each dissolving and measuring a different alloying element. This occurs because the carbon in high-C nickel-based alloys reacts with various metal elements in the nickel-based alloy to form substances such as chromium carbide, tungsten carbide, molybdenum carbide, vanadium carbide, titanium carbide, niobium carbide, and cobalt carbide. The dissolution of these substances can affect other substances that have already dissolved or are about to dissolve. Improving the dissolution method to produce a solution that can simultaneously measure multiple alloying elements with different properties through a single dissolution method is an urgent problem to be solved. Summary of the Invention

[0005] In response to the above-mentioned deficiencies in the prior art, the present invention provides a method for dissolving a nickel-based alloy sample. For a nickel-based alloy material with a C content of 0.15%-0.20%, concentrated hydrochloric acid and concentrated nitric acid are first used to dissolve it. Due to the high content of Cr, Mo and W, and the fact that they cannot affect the detection of Ce, Si and other metals, the method of adding concentrated nitric acid and concentrated hydrochloric acid is limited. Perchloric acid is then added to control the fuming of perchloric acid. Combined with the concentrated hydrochloric acid and concentrated nitric acid added in the early stage, the metal carbides are dissolved while avoiding the generation of CrO2Cl2, which leads to a low Cr content measurement. Hydrofluoric acid is combined to dissolve the undissolved yellow substance to avoid the generation of SiF4, which leads to a low Si content measurement.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is as follows: In one aspect, the present invention provides a method for dissolving a nickel-based alloy sample for use in determining the contents of multiple metal elements by IPC-AES, wherein, in the nickel-based alloy, carbon is 0.15%-0.20% by mass. The method comprises the following steps: preliminarily dissolving the sample with concentrated hydrochloric acid and concentrated nitric acid; adding perchloric acid, and keeping the sample at 100°C-120°C for 1-2 minutes to obtain a yellow insoluble substance, wherein the ratio of the added volume of the perchloric acid to the sample mass satisfies (110-130) mL:1 g; transferring the liquid and the yellow insoluble substance to a second reaction cup, adding hydrofluoric acid, and keeping the sample at 50°C-60°C for 2-4 minutes; and fixing the volume after the dissolution is complete to obtain the sample.

[0007] Furthermore, in the nickel-based alloy, by mass percentage, Cr is 20.0%-22.0%, Mo is 8.0%-9.0%, W is 7.8%-8.2%, Co is 12.0%-14.0%, Ce is 0.015%-0.025%, and Si is 0.85%-0.95%.

[0008] Furthermore, the preliminary dissolution process is as follows: at a temperature of 150°C-200°C, a first preset volume of concentrated hydrochloric acid is added to a first reaction cup, and when the sample sinks to the bottom, concentrated nitric acid and concentrated hydrochloric acid are gradually added dropwise, wherein the amount of concentrated nitric acid added is a second preset volume, and the amount of concentrated hydrochloric acid added is a third preset volume. After the addition is completed, the mixture is kept warm for 3-5 minutes, and the ratio of the first preset volume to the sample mass satisfies (80-100) mL:1 g, the ratio of the second preset volume to the sample mass satisfies (45-55) mL:1 g, and the third preset volume is 40%-50% of the first preset volume.

[0009] Furthermore, during the dropwise addition, the dropping speed of concentrated nitric acid is 0.8-1.2 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 15-20 drops / min, and the volume of each drop is about 0.04-0.06 mL.

[0010] Furthermore, the first reaction cup is made of glass.

[0011] Furthermore, the second reaction cup is made of tetrafluoroethylene.

[0012] Furthermore, the mass percentage concentration of the concentrated hydrochloric acid is 35%-38%, the mass percentage concentration of the nitric acid is 65%-68%, and the mass percentage concentration of the hydrofluoric acid is 40-44%.

[0013] Furthermore, the nickel-based alloy sample is in powder form, and the average particle size of the powder is 200µm-500µm.

[0014] Furthermore, the ratio of the added volume of the hydrofluoric acid to the mass of the sample satisfies: (25-35) mL: 1 g.

[0015] Furthermore, the hydrofluoric acid is added dropwise, and the dropping speed gradually decreases; the dropping rate of the first 2 / 3 of the volume is 30-40 drops / min, and the dropping rate of the remaining volume is 10-20 drops / min; the volume of each drop is about 0.04-0.06 mL.

[0016] Compared with the prior art, the technical solution provided by the present invention brings the following beneficial effects: The present invention provides a method for dissolving a nickel-based alloy sample. Specifically, for high-carbon nickel-based alloys, a large amount of chromium carbide, tungsten carbide, molybdenum carbide, vanadium carbide, titanium carbide, niobium carbide, cobalt carbide and the like are generated inside the alloy. These substances are difficult to dissolve, and perchloric acid is usually used. However, perchloric acid needs to be fuming to dissolve the carbides well. Based on the above problem, the present invention proposes first using concentrated hydrochloric acid and concentrated nitric acid to preliminarily dissolve the sample to form a metal ion salt solution, and then adding perchloric acid. Under the combined action of concentrated hydrochloric acid and concentrated nitric acid, the carbides are mainly dissolved. However, the dissolution of the carbides cannot affect the amount of other elements. For example, the generation of CrO2Cl2 during the reaction may result in a low Cr content measurement, or the fuming of perchloric acid may cause some metal ions to be carried out. Therefore, the amount of concentrated hydrochloric acid and concentrated nitric acid needs to be limited before adding perchloric acid. , fully ensuring that the subsequent fuming effect of perchloric acid is suppressed without affecting the dissolution of carbides. Secondly, the amount of perchloric acid added and the treatment process are strictly controlled, and then hydrofluoric acid is added. On the one hand, hydrofluoric acid dissolves the yellow insoluble matter. On the other hand, since perchloric acid produces less smoke, the remaining perchloric acid drives away the subsequent hydrofluoric acid, thereby reducing the residual hydrofluoric acid as much as possible. Finally, the present invention limits the order, amount and treatment process of adding perchloric acid and hydrofluoric acid. The purpose is that concentrated nitric acid and concentrated hydrochloric acid, perchloric acid and hydrogen fluoride work together to treat the high-carbon nickel-based high-temperature alloy in this application, avoiding the generation of volatile gases during the reaction of some metal ions with perchloric acid, resulting in low test results. Too little perchloric acid addition cannot dissolve carbides and cannot subsequently drive away excess hydrogen fluoride. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A photograph of a yellow precipitate during the dissolution process provided in Example 1 of the present invention; Figure 2 This is a physical picture of the dissolved sample provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more apparent, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific implementation methods of the present invention are not limited to the specific embodiments given herein, and those skilled in the art may make similar improvements without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and do not limit the present invention.

[0021] An embodiment of the present invention provides a method for dissolving a nickel-based alloy sample for determining the contents of multiple metal elements by IPC-AES. In the nickel-based alloy, C is 0.15%-0.20% by mass. The method comprises the following steps: S1, preliminarily dissolving the sample using concentrated hydrochloric acid and concentrated nitric acid; S2, adding perchloric acid, and keeping the sample at 100° C.-120° C. for 1-2 minutes to obtain a yellow insoluble substance, wherein the ratio of the added volume of the perchloric acid to the sample mass satisfies (110-130) mL:1 g; S3, transferring the liquid and the yellow insoluble substance to a second reaction cup, adding hydrofluoric acid, and keeping the sample at 50° C.-60° C. for 2-4 minutes; and S4, fixing the volume after the dissolution is completed.

[0022] The present invention provides a method for dissolving a nickel-based alloy sample. Specifically, for high-carbon nickel-based alloys, a large amount of chromium carbide, tungsten carbide, molybdenum carbide, vanadium carbide, titanium carbide, niobium carbide, cobalt carbide and the like are generated inside the alloy. These substances are difficult to dissolve, and perchloric acid is usually used. However, perchloric acid needs to be fuming to dissolve the carbides well. Based on the above problem, the present invention proposes first using concentrated hydrochloric acid and concentrated nitric acid to preliminarily dissolve the sample to form a metal ion salt solution, and then adding perchloric acid. Under the combined action of concentrated hydrochloric acid and concentrated nitric acid, the carbides are mainly dissolved. However, the dissolution of the carbides cannot affect the amount of other elements. For example, the generation of CrO2Cl2 during the reaction may result in a low Cr content measurement, or the fuming of perchloric acid may cause some metal ions to be carried out. Therefore, the amount of concentrated hydrochloric acid and concentrated nitric acid needs to be limited before adding perchloric acid. , fully ensuring that the subsequent fuming effect of perchloric acid is suppressed without affecting the dissolution of carbides. Secondly, the amount of perchloric acid added and the treatment process are strictly controlled, and then hydrofluoric acid is added. On the one hand, hydrofluoric acid dissolves the yellow insoluble matter. On the other hand, since perchloric acid produces less smoke, the remaining perchloric acid drives away the subsequent hydrofluoric acid, thereby reducing the residual hydrofluoric acid as much as possible. Finally, the present invention limits the order, amount and treatment process of adding perchloric acid and hydrofluoric acid. The purpose is that concentrated nitric acid and concentrated hydrochloric acid, perchloric acid and hydrogen fluoride work together to treat the high-carbon nickel-based high-temperature alloy in this application, avoiding the generation of volatile gases during the reaction of some metal ions with perchloric acid, resulting in low test results. Too little perchloric acid addition cannot dissolve carbides and cannot subsequently drive away excess hydrogen fluoride.

[0023] Specifically, in the nickel-based alloy of the present invention, by mass percentage, Cr is 20.0%-22.0%, Mo is 8.0%-9.0%, W is 7.8%-8.2%, Co is 12%-14%, Ce is 0.015%-0.025%, and Si is 0.85%-0.95%. It can be seen that the C content of the present application is relatively high compared to the nickel-based high-temperature alloys in the prior art, and it is easy to form metal carbides. How to ensure the dissolution of carbides without affecting the content of other elements, such as Si, Co, Ce, and B, is a key issue.

[0024] For illustration purposes, the composition of the nickel-based high-temperature alloy used in the present invention is roughly as shown in Table 1.

[0025] Table 1 Chemical composition of nickel-based superalloys

[0026] The rest is Ni element.

[0027] In step S1, the preliminary dissolution process is as follows: at a temperature of 150°C-200°C, a first preset volume of concentrated hydrochloric acid is added to a first reaction cup, and when the sample sinks to the bottom, concentrated nitric acid and concentrated hydrochloric acid are gradually added dropwise, wherein the amount of concentrated nitric acid added is a second preset volume, and the amount of concentrated hydrochloric acid added is a third preset volume. After the addition is completed, the mixture is kept warm for 3-5 minutes, and the ratio of the first preset volume to the sample mass satisfies (80-100) mL:1 g, the ratio of the second preset volume to the sample mass satisfies 45 mL-55 mL:1 g, and the third preset volume is 40%-50% of the first preset volume. The element composition in this application is complex, such as Cr, Mo, W and other easily passivated elements with a high content, which are easy to form a passivation film during the dissolution process. Therefore, it is necessary to limit the way of adding acid to avoid the formation of a passivation film at a high concentration that reduces the dissolution rate, and the acid solubility needs to be high for the sample to be well dissolved; secondly, it is necessary to consider the effect on the dissolution of other elements, such as Ce and Co. Ce is a rare earth metal and has good solubility under acidic conditions, but high acid concentrations easily generate volatile substances. Finally, the content of Co and Ni is relatively high. How to ensure the co-dissolution of the above elements? Dissolution requires strict restrictions on the proportion and method of acid addition. Specifically, a certain volume of concentrated hydrochloric acid is added first. When the sample sinks to the bottom, concentrated nitric acid and concentrated hydrochloric acid are gradually added. After the sample sinks to the bottom of the concentrated hydrochloric acid, concentrated nitric acid and concentrated hydrochloric acid are added. The first volume of concentrated hydrochloric acid dilutes and diffuses the concentrated nitric acid to avoid high local nitric acid concentration, which causes local passivation on the sample surface. Secondly, by gradually adding concentrated hydrochloric acid and concentrated nitric acid, the dissolution of other elements and the dissolution of easily passivated elements are taken into consideration, which shortens the time required for dissolution and avoids the test results being smaller than the standard value.

[0028] Preferably, when adding dropwise, the dropwise addition rate of concentrated nitric acid is 0.8-1.2 times that of concentrated hydrochloric acid, and the dropwise addition rate of concentrated nitric acid is 15-20 drops / min, with the volume of each drop being approximately 0.04-0.06 mL. The dropwise addition rate and amount will affect the dissolution behavior of the sample, and the use of the above-mentioned dropwise addition rates of concentrated nitric acid and concentrated hydrochloric acid can achieve: (1) a shorter dissolution time, which can be shortened to within 20 minutes; (2) effective dissolution of elements with high content such as Co and Ni; and (3) avoidance of passivation of elements with high content such as Cr, Mo, and W.

[0029] Preferably, the first reaction cup is made of glass.

[0030] Preferably, the second reaction cup is made of tetrafluoroethylene.

[0031] In the embodiment of the present invention, the mass percentage concentration of the concentrated hydrochloric acid is 35%-38%, the mass percentage concentration of the nitric acid is 65%-68%, and the mass percentage concentration of the hydrofluoric acid is 40-44%.

[0032] To further improve the sample dissolution rate, in the embodiments of the present invention, the nickel-based alloy sample is in powder form, with an average particle size of 200µm to 500µm. Powdered samples are more conducive to dissolution in acidic liquids, but the average particle size should not be too small. If the particle size is too small, some of the powder will not be easily wetted during the initial dissolution process, resulting in the powder suspending in the upper layer of the acidic solution. The subsequent addition of concentrated nitric acid and concentrated hydrochloric acid may deactivate some of the powder, resulting in the test results being lower than the standard value. The particle size should also not be too large, as this will reduce the powder dissolution efficiency.

[0033] The ratio of the added volume of hydrofluoric acid to the sample mass satisfies the following criteria: (25-35) mL: 1 g. While the addition of hydrofluoric acid can dissolve the yellow substance, it can corrode equipment during subsequent testing. Therefore, the volume of hydrofluoric acid added is limited to ensure that the amount is sufficient to dissolve the yellow solid precipitate while also being moderate enough to allow the remaining hydrofluoric acid to be driven off by the aforementioned perchloric acid after the reaction is complete.

[0034] Furthermore, the hydrofluoric acid is added dropwise at a decreasing rate; the first two-thirds of the volume is added at a rate of 30-40 drops / min, and the remaining volume is added at a rate of 10-20 drops / min; the volume of each drop is approximately 0.04-0.06 mL. This process further ensures that the hydrofluoric acid is completely removed. Furthermore, it prevents the generation of SiF4 gas during the dissolution of the Si element, which can result in an underestimation of the Si content.

[0035] In step S4, the dissolved liquid is diluted to a volume in a 100 mL polytetrafluoroethylene beaker and shaken for testing.

[0036] The present invention uses IPC-AES to determine the content of various metal elements in the high-carbon nickel-based superalloy provided by the present invention. For comparison, the present invention uses GB / T38939-2020, spark discharge atomic emission spectrometry, for detection. First, when performing IPC-AES and spark discharge atomic emission spectrometry measurements, the samples are measured continuously for at least 10 times, and the average values are then taken for comparison.

[0037] In order to further illustrate the present invention, the technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0038] Example 1 The embodiment of the present invention provides a method for dissolving a sample of the high-carbon nickel-based alloy in the present application, comprising: S1 Weigh 0.05g of sample with an average particle size of 200µm. Add concentrated hydrochloric acid at a ratio of 80mL:1g to the sample mass in a glass container at 150°C. When the sample sinks to the bottom, add concentrated nitric acid at a ratio of 45mL:1g to the sample mass. While adding concentrated nitric acid, add concentrated hydrochloric acid at 40% of the volume of the first added concentrated hydrochloric acid. After the addition is completed, keep warm for 3 minutes.

[0039] The dropping speed of concentrated nitric acid is 0.8 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 15 drops / min.

[0040] S2 was added with perchloric acid and kept at 100℃ for 1 min to obtain a yellow insoluble substance, such as Figure 1 As shown, the ratio of the added volume of perchloric acid to the mass of the sample satisfies 110 mL: 1 g.

[0041] S3: Transfer the liquid and the yellow insoluble matter into a polytetrafluoroethylene beaker, add hydrofluoric acid, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 25 mL: 1 g.

[0042] The hydrofluoric acid is added dropwise, and the dropping speed gradually decreases; the dropping speed for the first 2 / 3 of the volume is 30 drops / min, and the dropping speed for the remaining volume is 10 drops / min.

[0043] S4 Add the dissolved liquid to a 100mL polytetrafluoroethylene beaker and shake well for testing.

[0044] The dissolution time is 20 min, and the obtained dissolved sample photo is as follows Figure 2The metal and some non-metal elements of the high carbon nickel-based alloy sample were measured by IPC-AES, and the results are shown in Table 2.

[0045] Example 2 The embodiment of the present invention provides a method for dissolving a sample of the high-carbon nickel-based alloy in the present application, comprising: S1 Weigh 0.05g of sample with an average particle size of 300µm. Add concentrated hydrochloric acid at a ratio of 90mL:1g to the sample mass in a glass container at 180°C. When the sample sinks to the bottom, add concentrated nitric acid at a ratio of 50mL:1g to the sample mass. While adding concentrated nitric acid, add concentrated hydrochloric acid at 45% of the volume of the first added concentrated hydrochloric acid. After the addition is completed, keep warm for 5 minutes.

[0046] The dropping speed of concentrated nitric acid is 1 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 20 drops / min.

[0047] S2 added perchloric acid and kept warm at 110°C for 1 minute to obtain a yellow insoluble substance. The ratio of the added volume of perchloric acid to the sample mass was 120 mL:1 g.

[0048] S3: Transfer the liquid and the yellow insoluble matter into a polytetrafluoroethylene beaker, add hydrofluoric acid, and the ratio of the added volume of hydrofluoric acid to the mass of the sample is 30 mL: 1 g.

[0049] The hydrofluoric acid was added dropwise, and the dropping speed gradually decreased; the dropping speed for the first 2 / 3 of the volume was 35 drops / min, and the dropping speed for the remaining volume was 15 drops / min.

[0050] S4 Add the dissolved liquid to a 100mL polytetrafluoroethylene beaker and shake well for testing.

[0051] The dissolution time was 20 min. The metal and some non-metal elements of the high carbon nickel-based alloy sample were measured by IPC-AES. The results are shown in Table 2.

[0052] Example 3 The embodiment of the present invention provides a method for dissolving a sample of the high-carbon nickel-based alloy in the present application, comprising: S1 weighs 0.05 g of a sample with an average particle size of 500 µm. At 200°C, add concentrated hydrochloric acid in a ratio of 100 mL:1 g to the sample mass in a glass container. When the sample sinks to the bottom, add concentrated nitric acid in a ratio of 55 mL:1 g to the sample mass. While adding concentrated nitric acid, add concentrated hydrochloric acid at 50% of the volume of the first added concentrated hydrochloric acid. After the addition is completed, keep warm for 5 minutes.

[0053] The dropping speed of concentrated nitric acid is 1.2 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 20 drops / min.

[0054] S2 added perchloric acid and kept warm at 120°C for 2 minutes to obtain a yellow insoluble substance. The ratio of the added volume of perchloric acid to the sample mass was 130 mL:1 g.

[0055] S3: Transfer the liquid and the yellow insoluble matter into a polytetrafluoroethylene beaker, add hydrofluoric acid, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 35 mL: 1 g.

[0056] The hydrofluoric acid is added dropwise, and the dropping speed gradually decreases; the dropping speed for the first 2 / 3 of the volume is 40 drops / min, and the dropping speed for the remaining volume is 20 drops / min.

[0057] S4 Add the dissolved liquid to a 100mL polytetrafluoroethylene beaker and shake well for testing.

[0058] The dissolution time was 19 min. The metal and some non-metal elements of the high carbon nickel-based alloy sample were measured by IPC-AES. The results are shown in Table 2.

[0059] Example 4 The embodiment of the present invention provides a method for dissolving a sample of the high-carbon nickel-based alloy in the present application, comprising: S1: Weigh 0.05g of a sample with an average particle size of 200µm. Add concentrated hydrochloric acid to a glass container at 150°C at a ratio of 80mL:1g to sample mass. Once the sample has sunk to the bottom, add concentrated nitric acid at a ratio of 45mL:1g to sample mass. Simultaneously, add 40% of the volume of the first addition of concentrated hydrochloric acid. After the addition is complete, incubate for 3 minutes. Simultaneously add the concentrated nitric acid and concentrated hydrochloric acid to the glass.

[0060] S2 added perchloric acid and kept warm at 100°C for 1 min to obtain a yellow insoluble substance. The ratio of the added volume of perchloric acid to the sample mass was 110 mL:1 g.

[0061] S3: Transfer the liquid and the yellow insoluble matter into a polytetrafluoroethylene beaker, add hydrofluoric acid, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 25 mL: 1 g.

[0062] The hydrofluoric acid is added dropwise, and the dropping speed gradually decreases; the dropping speed for the first 2 / 3 of the volume is 30 drops / min, and the dropping speed for the remaining volume is 10 drops / min.

[0063] S4 Add the dissolved liquid to a 100mL polytetrafluoroethylene beaker and shake well for testing.

[0064] The dissolution time was 30 min. The metal and some non-metal elements of the high carbon nickel-based alloy sample were measured by IPC-AES. The results are shown in Table 2.

[0065] Example 5 The embodiment of the present invention provides a method for dissolving a sample of the high-carbon nickel-based alloy in the present application, comprising: S1 Weigh 0.05g of sample with an average particle size of 200µm. Add concentrated hydrochloric acid at a ratio of 80mL:1g to the sample mass in a glass container at 150°C. When the sample sinks to the bottom, add concentrated nitric acid at a ratio of 45mL:1g to the sample mass. While adding concentrated nitric acid, add concentrated hydrochloric acid at 40% of the volume of the first added concentrated hydrochloric acid. After the addition is completed, keep warm for 3 minutes.

[0066] The dropping speed of concentrated nitric acid is 0.8 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 15 drops / min.

[0067] S2 added perchloric acid and kept warm at 100°C for 1 min to obtain a yellow insoluble substance. The ratio of the added volume of perchloric acid to the sample mass was 110 mL:1 g.

[0068] S3: Transfer the liquid and the yellow insoluble matter into a polytetrafluoroethylene beaker, add hydrofluoric acid, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 25 mL: 1 g.

[0069] S4 Add the dissolved liquid to a 100mL polytetrafluoroethylene beaker and shake well for testing.

[0070] The dissolution time was 35 min. The metal and some non-metal elements of the high carbon nickel-based alloy sample were measured by IPC-AES. The results are shown in Table 2.

[0071] Comparative Example 1 Different from Example 1, in step S1 of this comparative example, a solution composed of concentrated nitric acid and concentrated hydrochloric acid of the same volume as in Example 1 was directly added to the glass, and then 0.05 g of the sample was added.

[0072] A passive film is formed and cannot be effectively dissolved.

[0073] Comparative Example 2 Different from Example 1, in step S2 of this comparative example, the ratio of the added volume of perchloric acid to the mass of the sample satisfies 100 mL:1 g.

[0074] The prepared liquid contains a certain amount of hydrogen fluoride. The metal and some non-metallic elements of the high carbon nickel-based alloy sample were measured using IPC-AES. The results are shown in Table 2.

[0075] Comparative Example 3 Different from Example 1, in step S2 of this comparative example, the ratio of the added volume of perchloric acid to the mass of the sample satisfies 130 mL:1 g.

[0076] IPC-AES was used to measure the metal and some non-metallic elements of the high carbon nickel-based alloy samples. The results are shown in Table 2.

[0077] Comparative Example 4 Different from Example 1, in step S3 of this comparative example, hydrofluoric acid is added, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 20 mL: 1 g.

[0078] IPC-AES was used to measure the metal and some non-metallic elements of the high carbon nickel-based alloy samples. The results are shown in Table 2.

[0079] Comparative Example 5 Different from Example 1, in step S3 of this comparative example, hydrofluoric acid is added, and the ratio of the added volume of hydrofluoric acid to the mass of the sample satisfies: 40 mL: 1 g.

[0080] The prepared liquid contains a certain amount of hydrogen fluoride. The metal and some non-metallic elements of the high carbon nickel-based alloy sample were measured using IPC-AES. The results are shown in Table 2.

[0081] Table 2 Chemical composition of nickel-based high-temperature alloys

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for dissolving a nickel-based alloy sample for determining the content of multiple metal elements by IPC-AES, characterized in that: In the nickel-based alloy, C is 0.15%-0.20% by mass; The following steps are involved: The sample was initially dissolved by concentrated hydrochloric acid and concentrated nitric acid; Add perchloric acid and keep warm at 100-120°C for 1-2 minutes to obtain a yellow insoluble substance. The ratio of the added volume of perchloric acid to the mass of the sample satisfies (110-130) mL: 1 g. Transfer the liquid and the yellow insoluble matter to a second reaction cup, add hydrofluoric acid, and keep warm at 50°C-60°C for 2 min-4 min; After dissolution is complete, adjust to volume.

2. The sample dissolution method according to claim 1, characterized in that: In the nickel-based alloy, by mass percentage, Cr is 20.0%-22.0%, Mo is 8.0%-9.0%, W is 7.8%-8.2%, Co is 12%-14%, Ce is 0.015%-0.025%, and Si is 0.85%-0.95%.

3. The sample dissolution method according to claim 2, characterized in that: The preliminary dissolution process is as follows: at a temperature of 150° C. to 200° C., a first preset volume of concentrated hydrochloric acid is added to a first reaction cup; when the sample sinks to the bottom, concentrated nitric acid and concentrated hydrochloric acid are gradually added dropwise; the amount of concentrated nitric acid added is a second preset volume; the amount of concentrated hydrochloric acid added is a third preset volume; after the addition is completed, the mixture is kept warm for 3 min to 5 min; the ratio of the first preset volume to the sample mass satisfies (80-100) mL:1 g; the ratio of the second preset volume to the sample mass satisfies (45-55) mL:1 g; and the third preset volume is 40% to 50% of the first preset volume.

4. The sample dissolution method according to claim 3, wherein: When adding dropwise, the dropping speed of concentrated nitric acid is 0.8-1.2 times that of concentrated hydrochloric acid, and the dropping flow rate of concentrated nitric acid is 15-20 drops / min, and the volume of each drop is about 0.04-0.06 mL.

5. The sample dissolution method according to claim 3, characterized in that: The first reaction cup is made of glass.

6. The sample dissolution method according to claim 3 or 5, characterized in that: The second reaction cup is made of tetrafluoroethylene.

7. The sample dissolution method according to claim 1, characterized in that: The mass percentage concentration of the concentrated hydrochloric acid is 35%-38%, the mass percentage concentration of the nitric acid is 65%-68%, and the mass percentage concentration of the hydrofluoric acid is 40-44%.

8. The sample dissolution method according to claim 1, characterized in that: The nickel-based alloy sample is in powder form, and the average particle size of the powder is 200 μm-500 μm.

9. The sample dissolution method according to claim 1, characterized in that: The ratio of the added volume of the hydrofluoric acid to the mass of the sample satisfies: (25-35) mL: 1 g.

10. The sample dissolution method according to claim 9, characterized in that: The hydrofluoric acid is added dropwise, and the speed of the addition gradually decreases; The first 2 / 3 of the volume is dropped at an acceleration rate of 30-40 drops / min, and the remaining volume is dropped at an acceleration rate of 10-20 drops / min; The volume of each drop is approximately 0.04-0.06 mL.

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