Alloy hot salt stress corrosion test method

Abstract

The invention discloses an alloy hot salt stress corrosion testing method which comprises the following steps: after 2N alloy samples are obtained, performing salt deposition treatment on scale distance sections of N alloy samples to obtain N samples with salt films; respectively mounting the N samples with the salt films and the N alloy samples in a durability testing machine, heating to a set test temperature, then carrying out heat preservation treatment, respectively breaking the N samples with the salt films under different stresses, and respectively breaking the N alloy samples under different stresses; then fitting test results of the M samples with the salt films and the M alloy samples at the set test temperature by adopting a fitting formula; and finally, setting the fitting parameter I of the M samples with the salt film as As, setting the fitting parameter II of the M samples with the salt film as Bs, setting the fitting parameter I of the M alloy samples as A0, setting the fitting parameter II of the M samples with the salt film as B0, and evaluating the thermal salt stress corrosion resistance of the alloy based on an As / A0 value and a Bs / B0 value.

Description

Technical Field

[0001] This invention relates to the field of alloy material testing technology, and in particular, to a method for testing hot salt stress corrosion of alloys. Background Technology

[0002] As advanced aero engines develop towards higher power-to-weight ratios, they are made of alloy materials with excellent performance. However, when operating in marine environments, they are prone to hot salt stress corrosion under complex conditions of high temperature, high salt, and high stress, which has an uncertain impact on the service life and reliability of the alloy. Therefore, it is necessary to accurately evaluate the alloy's resistance to hot salt stress corrosion.

[0003] Currently, existing testing methods such as salt spray testing (salt corrosion only), hot salt corrosion (hot + salt corrosion), and stress corrosion testing (stress + salt corrosion) can only simulate single or two-factor effects. They cannot reproduce the test conditions of high temperature (400-950℃), high stress (100-900MPa), and salt corrosion coupled during actual service, resulting in significant deviations between the evaluation results and engineering reality.

[0004] For example, Chinese invention patent application CN117723478A discloses a stress-thermal corrosion coupling test method, which includes the following steps: S1, pretreatment: the sample is ground and degreased, then weighed and the weight is recorded; S2, salting: the pretreated sample is heated and then salted; S3, test: two samples are connected by a connecting block, and clamp blocks are connected to the ends of the two samples that are far apart from each other. The samples are mounted on a creep quencher through the two clamp blocks and the test is conducted. The samples are heated during the test; S4, after the test, the samples are removed, one of the samples is weighed, and the corrosion kinetic curve of the sample is determined; one sample is used for corrosion product analysis, and the other sample is cold-mounted with epoxy resin and then cut to observe the cross-sectional morphology. However, the above test method focuses on corrosion products, corrosion kinetic curves, and fracture morphology analysis, and cannot directly and accurately evaluate the resistance of alloy materials to hot salt stress corrosion based on the test results, which is difficult to meet engineering requirements. Summary of the Invention

[0005] This invention provides a method for testing hot salt stress corrosion of alloys, in order to solve the technical problem that existing testing methods have significant deviations between the evaluation results and engineering practice, or cannot directly and accurately assess the resistance of alloys to hot salt stress corrosion.

[0006] According to one aspect of the present invention, a method for testing hot salt stress corrosion of alloys is provided, characterized by comprising the following steps: S1: Obtaining 2N alloy samples, each alloy sample including a clamping section and a gauge length section, and depositing salt on the gauge length sections of the N alloy samples respectively to obtain N samples with salt film, where N is an integer greater than 1; S2: Installing the N samples with salt film and the N alloy samples respectively in a stress-testing machine, heating to a set test temperature and holding for heat treatment, then causing the N samples with salt film to fracture under different stresses, and causing the N alloy samples to fracture under different stresses, and controlling the fracture time of M samples with salt film and M alloy samples within a set fracture time, where M is a positive integer, M ≤ N; S3: Using a fitting formula to fit the test results of the M samples with salt film and M alloy samples at the set test temperature, respectively, to obtain fitting parameters one and two for the M samples with salt film, and fitting parameters one and two for the M alloy samples, wherein the fitting formula is: t=A · σ –B In the formula: t is the fracture time, σ is the applied stress, A is the first fitting parameter, and B is the second fitting parameter; S4: Set the first fitting parameter of the M salt film samples as A s Let the fitting parameter 2 of the M salt film samples be B. s Let the fitting parameter one for the M alloy samples be A0, and the fitting parameter two for the M samples with salt films be B0, based on A s / A0 value and B s The / B0 value is used to assess the alloy's resistance to hot salt stress corrosion.

[0007] As a further improvement to the above technical solution: Furthermore, the method for controlling the fracture time within the set fracture time is as follows: select 0.8Rm to 0.95Rm as the initial test stress, obtain the corresponding fracture time, and when the fracture time is lower than the set fracture time, reduce the test stress of subsequent specimens; when the fracture time is higher than the set fracture time, increase the test stress of subsequent specimens, where Rm is the tensile strength of the alloy.

[0008] Further, in step S1, the specific steps of the salt deposition treatment are as follows: preheat the alloy sample to a surface temperature greater than 100°C, then spray the salt solution onto the gauge length section in a spray form, rotating the alloy sample during the spraying process, followed by drying, ensuring that the salt deposition amount on the dried gauge length section is 0.1 mg / cm³. 2 ~10mg / cm 2 .

[0009] Furthermore, the drying temperature is 100℃~120℃, and the drying time is 10min~30min.

[0010] Furthermore, the salt concentration in the brine is 0.1 wt% to 26.5 wt%.

[0011] Furthermore, the heat preservation treatment time is 1 hour to 3 hours.

[0012] Furthermore, the fracture time is set to 10h to 1000h, and M≥3.

[0013] Furthermore, the fracture time is defined as including X fracture time regions, which are arranged in ascending order. Each fracture time region contains at least one salt film sample and at least one alloy sample. X is a positive integer and X≤M.

[0014] Furthermore, the test temperature was set at 300℃-800℃.

[0015] Furthermore, before step S1, the steps include: cleaning the alloy sample and then installing a protective sleeve on the clamping section.

[0016] The present invention has the following beneficial effects: The alloy hot salt stress corrosion testing method of this invention involves obtaining 2N alloy samples, depositing salt on the gauge length of N of these samples to obtain N samples with salt films as the test group, and the remaining N alloy samples as the control group, ensuring that N is greater than 1 to improve the reliability of subsequent test results. The N samples with salt films and the N alloy samples are then installed in a long-term stress testing machine, heated to a set test temperature, and held at that temperature. The N samples with salt films and the N alloy samples are then fractured under different stresses to complete the tensile fracture tests of the test and control groups. The test group achieves three-field coupling of thermal field, salt corrosion field, and stress field, closely reflecting actual service conditions and providing a testing basis for the performance evaluation of alloys under complex conditions. The fracture time of at least M samples with salt films and at least M alloy samples is controlled within a set fracture time, ensuring that M is a positive integer less than N to improve the reliability of the test results. Then, the method uses t=A•σ. –B This fitting formula is applied to the test results of M salt film samples and M alloy samples at a set test temperature to obtain fitting parameters one and two for the M salt film samples, and fitting parameters one and two for the M alloy samples, providing data support for the subsequent hot salt stress corrosion resistance of the alloys; finally, the fitting parameter one for the M salt film samples is set as A. s Let the fitting parameter 2 of the M salt film samples be B. s Let the fitting parameter one for the M alloy samples be A0, and the fitting parameter two for the M samples with salt films be B0, based on A s / A0 value and B sThe / B0 value is used to assess the alloy's resistance to hot salt stress corrosion, enabling a direct and accurate evaluation of its resistance. Compared to existing technologies, this method closely matches the actual service conditions of the alloy, significantly reducing the deviation between the evaluation results and engineering realities. It can directly and accurately assess the alloy's resistance to hot salt stress corrosion, providing a reliable testing basis for the alloy's application in marine environments. Furthermore, the testing process is highly standardized and repeatable, making it widely applicable to the evaluation of the hot salt stress corrosion resistance of various alloys. It is highly practical and suitable for widespread promotion and application.

[0017] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0018] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a flowchart illustrating the steps of a preferred embodiment of the alloy hot salt stress corrosion testing method of the present invention. Detailed Implementation

[0019] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of this specification.

[0020] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not restrictive. For example, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein may also include the plural forms. When used in this specification, the terms “comprising,” “including,” and / or “containing” mean that the associated integers, steps, operations, elements, and / or components are present, but do not preclude the presence of one or more other features, integers, steps, operations, elements, components, and / or groups, or that other features, integers, steps, operations, elements, components, and / or groups may be added to the system / method.

[0021] Considering the following description, these and other features of this specification, as well as the operation and function of the related components of the structure, and the economy of assembly and manufacture of the parts, can be significantly improved. All of these form part of this specification with reference to the accompanying drawings. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale.

[0022] like Figure 1 As shown, the alloy hot salt stress corrosion testing method of this embodiment includes the following steps: S1: Obtain 2N alloy samples, each alloy sample including a clamping section and a gauge length section, and deposit salt on the gauge length sections of the N alloy samples respectively to obtain N samples with salt film, where N is an integer greater than 1; S2: Install the N samples with salt film and the N alloy samples in a rupture testing machine, heat to the set test temperature and hold for heat treatment, then cause the N samples with salt film to fracture under different stresses, and cause the N alloy samples to fracture under different stresses, and control the fracture time of at least M samples with salt film and at least M alloy samples within the set fracture time, where M is a positive integer and M ≤ N; S3: Use a fitting formula to fit the test results of the N samples with salt film and the N alloy samples at the set test temperature to obtain fitting parameters one and two for the N samples with salt film, and fitting parameters one and two for the N alloy samples, wherein the fitting formula is: t= A · σ –B In the formula: t is the fracture time, σ is the applied stress, A is the first fitting parameter, and B is the second fitting parameter; S4: Set the first fitting parameter of N salt film samples as A s Let the fitting parameter 2 of the N salt film samples be B. s Let the fitting parameter one for N alloy samples be A0, and the fitting parameter two for N samples with salt film be B0, based on A s / A0 value and B s The / B0 value is used to assess the alloy's resistance to hot salt stress corrosion.

[0023] like Figure 1As shown, specifically, the alloy hot salt stress corrosion testing method of the present invention, after obtaining 2N alloy samples, deposits salt on the gauge length of N of the alloy samples to obtain N samples with salt film as the test group, and the remaining N alloy samples are also used as the test group, ensuring that N is greater than 1 to improve the reliability of subsequent test results; then, the N samples with salt film and the N alloy samples are respectively installed in a long-term testing machine, heated to the set test temperature and held for heat treatment, and then the N samples with salt film are fractured under different stresses, and the N alloy samples are fractured under different stresses to complete the tensile fracture test of the test group and the control group. The test group realizes the three-field coupling of thermal field, salt corrosion field and stress field, which is close to the actual service conditions and provides a test basis for the performance evaluation of alloys under complex conditions. The fracture time of M samples with salt film and M alloy samples is controlled within the set fracture time, and M is a positive integer less than N to improve the reliability of test results; then, t=A•σ is used. –B This fitting formula is applied to the test results of M salt film samples and M alloy samples at a set test temperature to obtain fitting parameters one and two for the M salt film samples, and fitting parameters one and two for the M alloy samples, providing data support for the subsequent hot salt stress corrosion resistance of the alloys; finally, the fitting parameter one for the M salt film samples is set as A. s Let the fitting parameter 2 of the M salt film samples be B. s Let the fitting parameter one for the M alloy samples be A0, and the fitting parameter two for the M samples with salt films be B0, based on A s / A0 value and B s The / B0 value is used to assess the alloy's resistance to hot salt stress corrosion, enabling a direct and accurate evaluation of its resistance. Compared to existing technologies, this method closely matches the actual service conditions of the alloy, significantly reducing the deviation between the evaluation results and engineering realities. It can directly and accurately assess the alloy's resistance to hot salt stress corrosion, providing a reliable testing basis for the alloy's application in marine environments. Furthermore, the testing process is highly standardized and repeatable, making it widely applicable to the evaluation of the hot salt stress corrosion resistance of various alloys. It is highly practical and suitable for widespread promotion and application.

[0024] Optionally, the alloy specimen also includes a transition section disposed between the clamping section and the gauge length section, which connects the clamping section and the gauge length section into a whole.

[0025] Optionally, there are two clamping sections, and the transition section and clamping section are arranged in a one-to-one correspondence, with the clamping section and transition section arranged at opposite ends of the gauge length section.

[0026] Optionally, the clamping section is provided with connecting threads, and the clamping section is reliably connected to the endurance testing machine through the connecting threads.

[0027] Optionally, the gauge length section is arranged in a cylindrical shape, and the transition section is arranged in an arc shape.

[0028] Alternatively, the alloys include Ti2AlNb alloys, titanium-aluminum intermetallic compound alloys, and high-temperature titanium alloys.

[0029] It should be understood that by depositing salt on the gauge length of the alloy sample, the salt hydrolyzes to form ions, which react with the alloy to release active hydrogen atoms. These hydrogen atoms penetrate into the grain boundaries or phase interfaces, causing hydrogen embrittlement.

[0030] It should be understood that, at the set test temperature, the interfacial energy of the O phase / B2 phase in the alloy can be reduced, which can exacerbate crack propagation along the phase boundary.

[0031] It should be understood that by applying stress, the passivation film on the alloy can be accelerated to break and hydrogen diffusion can be driven, resulting in a significantly shorter fracture life of the sample with salt film compared to the alloy sample without salt film under the same stress, and the effect of stress on corrosion sensitivity is more significant.

[0032] It should be understood that A s The larger the value of A0 and / or B, the greater the value of B. s The smaller the / B0 value, the better the alloy's resistance to hot salt stress corrosion; A s The smaller the A0 value and / or B s The higher the / B0 value, the worse the alloy's resistance to hot salt stress corrosion.

[0033] In this embodiment, the method for controlling the fracture time within a set fracture time is as follows: 0.8Rm to 0.95Rm is selected as the initial test stress, and the corresponding fracture time is obtained. When the fracture time is lower than the set fracture time, the test stress of subsequent samples is reduced; when the fracture time is higher than the set fracture time, the test stress of subsequent samples is increased. Here, Rm is the tensile strength of the alloy. Specifically, the fracture times of M salt film samples and M alloy samples are controlled within the set fracture time using the above method to improve the accuracy of the test results and thus improve the reliability of subsequent evaluation results. Specifically, when the initial test stress is 0.8Rm to 0.95Rm, the fracture time is moderate and convenient for guiding subsequent test stresses; when the initial test stress is less than 0.8Rm or greater than 0.95Rm, the fracture time is too long or too short, and is not valid data, making it inconvenient for guiding subsequent test stresses.

[0034] In this embodiment, the specific steps of the salt deposition treatment are as follows: the alloy sample is preheated to a surface temperature greater than 100°C, then the salt solution is sprayed onto the gauge length section in a spraying manner, while rotating the alloy sample during the spraying process, followed by drying, and the salt deposition amount on the gauge length section after drying is 0.1 mg / cm³. 2 ~10mg / cm2 Specifically, in the above steps, the preheating temperature is controlled to ensure rapid evaporation of moisture in the salt solution and to avoid mitigating the impact of the salt deposition stage on the alloy sample; the amount of salt deposited on the gauge length after drying is precisely controlled to accurately reflect the alloy's resistance to hot salt stress corrosion under different levels of salt deposition; and the alloy sample is rotated during spraying to ensure uniform salt spraying, realistically simulating actual service conditions and improving the reliability of the evaluation results. Specifically, when the salt deposition amount is 0.1 mg / cm³... 2 ~10mg / cm 2 When the corrosion effect is closer to the actual service conditions, it has engineering reference value; when the salt deposition is less than 0.1 mg / cm³, the corrosion effect is more similar to the actual service conditions. 2 Or greater than 10 mg / cm 2 If the corrosion effect is too small or too large, it has no engineering reference value.

[0035] Optionally, the salt deposition on the gauge length after drying can be 0.1 mg / cm³. 2 0.5 mg / cm 2 1mg / cm 2 3mg / cm 2 5mg / cm 2 8mg / cm 2 10mg / cm 2 Or a range consisting of any two of them.

[0036] Optionally, the alloy sample is preheated to a surface temperature of 105℃ to 120℃. When the surface temperature of the alloy sample after preheating is between 105℃ and 120℃, the water in the salt solution evaporates rapidly, thus avoiding the reduction of the impact of the salt deposition stage on the alloy sample. When the surface temperature of the alloy sample after preheating is less than 105℃, the water in the salt solution evaporates slowly, affecting the efficiency of the salt deposition process. When the surface temperature of the alloy sample after preheating is greater than 120℃, the impact of the salt deposition stage on the alloy sample will be reduced, thereby affecting the accuracy of subsequent test results.

[0037] Optionally, the surface temperature of the alloy sample after preheating can be a range of 105°C, 108°C, 110°C, 115°C, 120°C, or any combination thereof.

[0038] It should be understood that the amount of salt deposited on the gauge length after drying can be calculated by measuring the mass of the alloy sample before salt deposition treatment and the mass of the alloy sample after drying treatment.

[0039] In this embodiment, the drying temperature is 100℃~120℃, and the drying time is 10min~30min. Specifically, when the drying temperature is between 100℃ and 120℃ and the drying time is between 10min and 30min, no moisture will remain after drying, and the experimental efficiency will not be affected.

[0040] In this embodiment, the salt concentration in the brine solution is between 0.1 wt% and 26.5 wt%. Specifically, when the salt concentration is between 0.1 wt% and 26.5 wt%, the salt can dissolve, and the salt deposition time is appropriate; when the salt concentration is less than 0.1 wt%, the salt deposition time is too long; and when the salt concentration is greater than 26.5 wt%, the salt cannot dissolve.

[0041] Optionally, the mass concentration of the salt can be a range of 0.1 wt%, 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 24 wt%, 26.5 wt%, or any combination thereof.

[0042] Optionally, the brine solution includes sodium chloride and sodium sulfate.

[0043] In this embodiment, the heat preservation treatment time is 1 hour to 3 hours. Specifically, when the heat preservation treatment time is between 1 hour and 3 hours, the temperature of the treated sample is uniform and it does not affect the test efficiency.

[0044] In this embodiment, the fracture time is set to 10h to 1000h, and M ≥ 3. Specifically, when the fracture time is set between 10h and 1000h, the range is wide enough to ensure that the parameters obtained by the fitting formula are accurate, thereby improving the reliability of the evaluation results.

[0045] In this embodiment, the fracture time is defined as X fracture time regions, arranged in ascending order. Each fracture time region contains at least one sample with a salt film and at least one alloy sample, where X is a positive integer and X ≤ M. Specifically, by ensuring that each fracture time region contains at least one sample with a salt film and at least one alloy sample, and that X is a positive integer and X ≤ M, the accuracy of the fitted parameters one and two obtained through fitting is ensured, thereby improving the reliability of the evaluation results.

[0046] Optionally, in one embodiment, the X fracture time regions are 10h-15h, 28h-32h, 48h-52h, 95h-105h, 450h-550h, and 900h-1000h, respectively.

[0047] In this embodiment, the test temperature is set to 300℃-800℃. Specifically, when the test temperature is set between 300℃ and 800℃, it can cover the high temperatures in actual service, thereby accurately reflecting the alloy's resistance to salt thermal stress corrosion at actual service temperatures. When the test temperature is set below 300℃ or above 800℃, it exceeds the actual service temperature range, causing the test results at that temperature to interfere with subsequent evaluation results.

[0048] In this embodiment, before step S1, the steps include: cleaning the alloy sample and then installing a protective sleeve on the clamping section. Specifically, cleaning the alloy sample helps to eliminate external interference factors as much as possible, and installing a protective sleeve on the clamping section prevents salt from depositing on the clamping section during the salt deposition treatment, thus making it impossible to accurately determine the amount of salt deposited on the gauge section and thus interfering with the evaluation results.

[0049] Optionally, the alloy sample can be ultrasonically cleaned with alcohol.

[0050] In one embodiment: Prepare 12 alloy samples (Ti2AlNb alloy), using 100% NaCl (chemically pure), and prepare a 15% salt solution with deionized water; Six alloy samples were taken, and protective sleeves were installed in the clamping section of the samples to ensure that only the gauge length section cracked. The samples were heated to a surface temperature of 105–110°C, and salt solution was sprayed onto the gauge length section using a salt spraying device. The alloy samples rotated during spraying, and then dried in an oven at 105–110°C for 10 minutes. The salt deposition on the gauge length section of the alloy samples was 1.55 mg / cm³. 2 ±0.3mg / cm 2 Six samples with salt films were obtained. Six salt-coated specimens and six alloy specimens were mounted in the endurance testing machine using a threaded clamp. After heating to 650℃ and holding for 2 hours, an initial test stress of 0.85 Rm was applied to one salt-coated specimen and one alloy specimen. Based on the corresponding fracture time, stresses of 220 MPa, 160 MPa, 130 MPa, 90 MPa, and 60 MPa were applied to the remaining five salt-coated specimens, respectively, and the corresponding fracture times were measured to be 15.1 h, 22.5 h, 61.6 h, 122.6 h, and 525.2 h. Stresses of 600 MPa, 520 MPa, 480 MPa, 440 MPa, and 350 MPa were applied to the remaining five alloy specimens, and the corresponding fracture times were measured to be 12.5 h, 28.3 h, 58.5 h, 115.6 h, and 565.2 h. The test results of 5 salt film samples and 5 alloy samples at the set test temperature were fitted using fitting formulas to obtain fitting parameters one and two for the 5 salt film samples, and fitting parameters one and two for the 5 alloy samples. The fitting parameter 1 for the five salt film samples is set as A. s The fitting parameter 2 for the five salt-coated samples is set as B. s The fitting parameter one for the five alloy samples is set as A0, and the fitting parameter two for the five samples with salt film is set as B0, i.e., A s =573.3, Bs=0.37, A0=844.2, B0=0.14, we find that A s / A0 value is 0.67, B s The / B0 value is 2.64.

[0051] In one embodiment: Prepare 12 alloy samples (Ti2AlNb alloy), and use 5% NaCl (chemically pure) + 95% Na2SO4 (chemically pure) to prepare a 15% salt solution with deionized water; Six alloy samples were taken, and protective sleeves were installed in the clamping section of the samples to ensure that only the gauge length section cracked. The samples were heated to a surface temperature of 105–110°C, and salt solution was sprayed onto the gauge length section using a salt spraying device. The alloy samples were rotated during spraying, and then dried in an oven at 105–110°C for 10 minutes. The salt deposition on the gauge length section of the alloy samples was 3 mg / cm³. 2 ±0.5mg / cm 2 Six samples with salt films were obtained. Six salt film specimens and six alloy specimens were installed in the endurance testing machine using the threaded chuck clamp. After heating to 500°C and holding for 2 hours, an initial test stress of 0.85Rm was applied to one salt film specimen and one alloy specimen. The fracture time of the five salt film specimens and five alloy specimens was controlled within the set fracture time according to the corresponding fracture time. The test results of 5 salt film samples and 5 alloy samples at the set test temperature were fitted using fitting formulas to obtain fitting parameters one and two for the 5 salt film samples, and fitting parameters one and two for the 5 alloy samples. The fitting parameter 1 for the five salt film samples is set as A. s The fitting parameter 2 for the five salt-coated samples is set as B. s Let the fitting parameter 1 of the 5 alloy samples be A0, and the fitting parameter 2 of the 5 samples with salt film be B0. The result is: A s / A0 value is 0.78, B s The / B0 value is 1.85.

[0052] Furthermore, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some implementations, multitasking and parallel processing are possible or potentially advantageous.

[0053] In summary, after reading the detailed disclosure of this specification, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand that this specification requires various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be made by this specification and are within the spirit and scope of the exemplary embodiments described herein.

[0054] Furthermore, certain terms in this specification have been used to describe embodiments of this specification. For example, "an embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of this specification. Therefore, it is to be emphasized and understood that two or more references to "an embodiment" or "an embodiment" or "alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. Moreover, specific features, structures, or characteristics may be suitably combined in one or more embodiments of this specification.

[0055] It should be understood that in the foregoing description of the embodiments in this specification, various features are combined in a single embodiment, drawing, or description for the purpose of simplifying the description and aiding in the understanding of a feature. However, this does not mean that the combination of these features is necessary, and those skilled in the art may readily identify some of the devices as separate embodiments when reading this specification. That is, the embodiments in this specification can also be understood as an integration of multiple secondary embodiments. It is also valid when each secondary embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

[0056] Each patent, patent application, publication of the patent application, and other materials such as articles, books, specifications, publications, documents, articles, etc., cited herein may be incorporated by reference hereafter. For example, in the event of any inconsistency or conflict between the description, definition, and / or use of terms related to any of the included materials and those related to this document, the terms used herein shall prevail.

[0057] Finally, it should be understood that the embodiments disclosed herein are illustrative of the principles of the embodiments described in this specification. Other modified embodiments are also within the scope of this specification. Therefore, the embodiments disclosed in this specification are merely examples and not limitations. Those skilled in the art can implement the applications described in this specification using alternative configurations based on the embodiments in this specification. Therefore, the embodiments in this specification are not limited to the embodiments precisely described in the applications.

Claims

1. A method for testing hot salt stress corrosion of alloys, characterized in that, Includes the following steps: S1: Obtain 2N alloy samples, each including a clamping section and a gauge length section, and deposit salt on the gauge length sections of the N alloy samples respectively to obtain N samples with salt film, where N is an integer greater than 1. S2: Install N salt film samples and N alloy samples in a rupture testing machine, heat them to the set test temperature and then hold them at the temperature. Then, make the N salt film samples break under different stresses and make the N alloy samples break under different stresses. Control the breaking time of M salt film samples and M alloy samples within the set breaking time, where M is a positive integer and M ≤ N. S3: The test results of M salt film samples and M alloy samples at the set test temperature are fitted using fitting formulas to obtain fitting parameters one and two for the M salt film samples, and fitting parameters one and two for the M alloy samples. The fitting formula is as follows: t=A · σ –B In the formula: t is the fracture time, σ is the applied stress, A is the first fitting parameter, and B is the second fitting parameter; S4: Set the fitting parameters of the M salt film samples as A. s Let the fitting parameter 2 of the M salt film samples be B. s Let the fitting parameter one for the M alloy samples be A0, and the fitting parameter two for the M samples with salt films be B0, based on A s / A0 value and B s The / B0 value is used to assess the alloy's resistance to hot salt stress corrosion.

2. The alloy hot salt stress corrosion test method according to claim 1, characterized in that, The method to control the fracture time within the set fracture time is as follows: The initial test stress was selected as 0.8Rm to 0.95Rm, and the corresponding fracture time was obtained. When the fracture time was lower than the set fracture time, the test stress of subsequent specimens was reduced. When the fracture time is higher than the set fracture time, the test stress of subsequent specimens is increased, where Rm is the tensile strength of the alloy.

3. The alloy hot salt stress corrosion test method according to claim 1, characterized in that, In step S1, the specific steps of the salt deposition treatment are as follows: The alloy sample was preheated to a surface temperature greater than 100°C. Then, the salt solution was sprayed onto the gauge length section while rotating the sample during spraying. The sample was then dried, with the salt deposition on the dried gauge length section set at 0.1 mg / cm³. 2 ~10mg / cm 2 .

4. The alloy hot salt stress corrosion test method according to claim 3, characterized in that, The drying temperature is 100℃~120℃, and the drying time is 10min~30min.

5. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, In the brine solution, the salt concentration ranges from 0.1 wt% to 26.5 wt%.

6. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, The heat preservation treatment time is 1 hour to 3 hours.

7. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, The fracture time is set to 10h~1000h, and M≥3.

8. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, The fracture time is set to include X fracture time regions, which are arranged in ascending order. Each fracture time region contains at least one salt film sample and at least one alloy sample. X is a positive integer, and X≤M.

9. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, The test temperature was set at 300℃-800℃.

10. The alloy hot salt stress corrosion test method according to any one of claims 1-4, characterized in that, Step S1 is preceded by the following steps: The alloy sample is cleaned, and then a protective sleeve is installed on the clamping section.

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