Rapid destressing method for nickel-based alloy

Abstract

The invention relates to the field of heat treatment of aeronautical materials, in particular to a rapid destressing method for nickel-based alloy. The method provided by the invention aims to solve the problems of high strength, poor plasticity, relatively large residual stress and the like of a sample formed by additive manufacturing by adopting a rapid heating method, and the electromagnetic induction heating technology is applied to improvement of an additive manufacturing material for the first time; a circular treatment method of electromagnetic induction heating and intermittent cooling (namely, the step S1 and the step S2 are repeated for more than five times) is adopted, the inherent thinking that single-time heat treatment is generally adopted in a conventional heat treatment method is broken through, and the hardness of the material is rapidly improved within a short time through the treatment method. Experiments show that compared with an untreated GH4169 sample formed by selective laser melting, the hardness is remarkably improved after electromagnetic induction heating treatment, and the hardness can reach 50 HV or above.

Description

Technical Field

[0001] The invention relates to the field of heat treatment of aviation materials, in particular to a rapid stress relief method for a nickel-based alloy. Background Art

[0002] As a nickel-based high-temperature alloy, GH4169 has excellent high-temperature mechanical properties, fatigue resistance and corrosion resistance, and is widely used in aerospace, nuclear energy, petrochemical and other fields. However, these parts are usually very complex in shape, and traditional processing methods are difficult or even impossible to process. Therefore, 3D printing, a new material forming method, can quickly manufacture parts of any complex shape by accumulating layer by layer, and has gained widespread attention. However, the samples formed by it usually show problems such as high strength, poor plasticity and large residual stress, so they need to be eliminated through appropriate post-heat treatment methods to improve the comprehensive mechanical properties. Traditional heat treatment methods mainly include stress relief annealing, solid solution + aging treatment, etc., and this process is generally completed in a heat treatment furnace. However, traditional heat treatment methods take a long time, consume high energy, and have requirements on sample size.

[0003] Electromagnetic induction heating uses the thermal effect of induced eddy currents to quickly heat samples, which can effectively improve productivity, reduce energy consumption, and can process samples of any size. At present, this technology is mainly used for surface quenching of materials, which can improve the surface hardness of the material and thus improve wear resistance. For example, the invention patent with patent number CN112813235A discloses an induction heating tempering treatment method, which is used to solve the technical problem of difficult local tempering treatment when there are differences in the technical indicators of multiple parts of a single rolling mill product. The invention patent with patent number CN114934167A discloses a composite heat treatment process of induction heating and pit furnace heating, which is used to solve the problem that the heating process of the workpiece after being placed in the furnace is relatively time-consuming, affecting the heat treatment production efficiency.

[0004] The above-mentioned application of induction heating technology is mainly used in traditional manufacturing methods, and most of them are for the purpose of quenching heating. In addition, the processing method is relatively simple, and only a single heating treatment is performed. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a method for quickly relieving stress of nickel-based alloys. The method provided by the present invention can perform partial or complete heating treatment on nickel-based high-temperature alloy molding materials and their products of different sizes, thereby removing stress in a short time and efficiently.

[0006] The present invention provides a method for rapidly relieving stress of a nickel-based alloy, comprising the following steps:

[0007] S1) subjecting the nickel-based alloy to electromagnetic induction heating for 30 s to 120 s;

[0008] S2) cooling the nickel-based alloy after step S1) for 10 s to 60 s;

[0009] S3) Repeat steps S1) and S2) at least 5 times.

[0010] The nickel-based alloy described in the present invention is specifically GH4169 alloy. The nickel-based alloy described in the present invention is a nickel-based alloy material obtained by 3D printing; specifically, the present invention is directed to a nickel-based alloy material obtained by 3D printing technology of selective laser melting (SLM). In one embodiment of the present invention, the nickel-based alloy is GH4169 nickel-based high temperature alloy.

[0011] The present invention firstly performs electromagnetic induction heating treatment on the nickel-based alloy, wherein the electromagnetic induction heating treatment is performed by an electromagnetic induction coil, and the distance between the nickel-based alloy and the electromagnetic induction coil is 2 mm to 10 mm. The electromagnetic induction heating treatment time of the present invention is 30 s to 120 s, preferably 30 s to 60 s.

[0012] After the nickel-based alloy is subjected to electromagnetic induction heating, the nickel-based alloy after the electromagnetic induction heating is cooled for 10 s to 60 s. In one embodiment of the present invention, the cooling is water cooling, and the cooling time is 10 s to 30 s. In another embodiment of the present invention, the cooling is air cooling, and the cooling time is 30 s to 60 s.

[0013] The present invention cools the nickel-based alloy after the electromagnetic induction heating treatment, and then performs the electromagnetic induction heating treatment and cooling in sequence for one time as one repetition, and repeats the electromagnetic induction heating treatment and cooling for at least 5 times. Preferably, the number of repetitions is 5 to 40 times. More preferably, the number of repetitions is 5 to 25 times. The present application repeatedly performs the electromagnetic induction heating treatment and cools the nickel-based alloy for a certain period of time, which can significantly improve the hardness of the nickel-based alloy and achieve the effect of short-term and efficient stress removal.

[0014] In one embodiment of the present invention, the method for rapid stress relief of nickel-based alloys of the present invention comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 30 s to 40 s; S2) air cooling the nickel-based alloy after step S1) for 30 s to 40 s; S3) repeating step S1) and step S2) for 5 to 8 times.

[0015] In one embodiment of the present invention, the method for rapid stress relief of nickel-based alloys of the present invention comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 50 s to 60 s; S2) water cooling the nickel-based alloy after step S1) for 10 s to 20 s; S3) repeating step S1) and step S2) for 8 to 12 times.

[0016] In one embodiment of the present invention, the method for rapid stress relief of nickel-based alloys of the present invention comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 50 s to 60 s; S2) air cooling the nickel-based alloy after step S1) for 50 s to 60 s; S3) repeating step S1) and step S2) for 13 to 17 times.

[0017] In one embodiment of the present invention, the method for rapid stress relief of nickel-based alloys of the present invention comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 50 s to 60 s; S2) water cooling the nickel-based alloy after step S1) for 10 s to 20 s; S3) repeating step S1) and step S2) for 18 to 22 times.

[0018] The present invention provides a method for rapidly relieving stress of a nickel-based alloy, comprising the following steps:

[0019] S1) subjecting the nickel-based alloy to electromagnetic induction heating for 30 s to 120 s;

[0020] S2) cooling the nickel-based alloy after step S1) for 10 s to 60 s;

[0021] S3) Repeat steps S1) and S2) at least 5 times.

[0022] The method provided by the present invention aims to solve the problems of high strength, poor plasticity and large residual stress of samples formed by additive manufacturing by a rapid heating method. For the first time, electromagnetic induction heating technology is applied to improve additive manufacturing materials. A cyclic treatment method of electromagnetic induction heating and intermittent cooling is adopted (i.e., step S1 and step S2 are repeated more than 5 times), breaking the inherent thinking of single heat treatment in conventional heat treatment methods. Through this treatment method, the hardness of the material is quickly improved in a short time.

[0023] Compared with traditional heat treatment methods, the advantages of the present invention are as follows: 1. It is highly efficient in a short time and can quickly reach the required temperature, thereby significantly reducing energy consumption and reducing production costs. 2. It can process a wide range of sample sizes, has strong operability, and can also perform separate heating treatments on local areas. 3. It is easy to achieve large-scale automated production in industry. Experiments show that compared with the untreated GH4169 sample formed by selective laser melting, the hardness after electromagnetic induction heating treatment has been significantly improved, reaching more than 50 HV. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The microstructure diagram of the original state of the GH4169 alloy prepared by the selective laser melting of the present invention;

[0025] Figure 2 This is a microstructure diagram of the sample after 10 times of electromagnetic induction treatment in Example 2 of the present invention;

[0026] Figure 3 This is the microstructure diagram of this embodiment after 20 times of electromagnetic induction treatment. DETAILED DESCRIPTION

[0027] The present invention discloses a method for rapid stress relief of nickel-based alloys. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0028] The present invention conducts experiments on GH4169 alloy prepared by selective laser melting. Figure 1 As shown, Figure 1 The microstructure of the original state of the GH4169 alloy prepared by selective laser melting of the present invention is shown in FIG. The original state hardness of the GH4169 alloy prepared by selective laser melting of the present invention is 304 HV.

[0029] The present invention will be further described below in conjunction with embodiments:

[0030] Example 1

[0031] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 5 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0032] Step 2: electromagnetic induction heating the sample after step 1 for 30 s;

[0033] Step 3: air cool the sample after step 2 for 30 s;

[0034] Step 4: Repeat steps 2 and 3 for a total of 5 times to obtain the final product.

[0035] In this example, after five electromagnetic induction heating treatments, the hardness of the SLM GH4169 alloy is 318 HV, which is 14 HV higher than that of the original sample (304 HV).

[0036] Example 2

[0037] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 2 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0038] Step 2: electromagnetic induction heating the sample after step 1 for 60 s;

[0039] Step 3: Cool the sample after step 2 in water for 15 s;

[0040] Step 4: Repeat steps 2 and 3 10 times to obtain the final product.

[0041] like Figure 2 As shown, Figure 2 The microstructure of the sample of Example 2 of the present invention after 10 times of electromagnetic induction treatment is shown in FIG. Figure 2 It can be seen that the low-magnification microstructure of the treated sample is different from the original state ( Figure 1 ) showed no significant difference, but the white precipitates in the high-magnification tissue increased significantly.

[0042] In this example, after 10 electromagnetic induction heating treatments, the hardness of the SLM GH4169 alloy is 354 HV, which is 50 HV higher than that of the original sample (304 HV).

[0043] Example 3

[0044] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 10 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0045] Step 2: electromagnetic induction heating the sample after step 1 for 60 s;

[0046] Step 3: air cool the sample after step 2 for 60 s;

[0047] Step 4: Repeat steps 2 and 3 for a total of 15 times to obtain the final product.

[0048] In this example, after five electromagnetic induction heating treatments, the hardness of the SLM GH4169 alloy is 341 HV, which is 37 HV higher than that of the original sample (304 HV).

[0049] Example 4

[0050] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 2 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0051] Step 2: electromagnetic induction heating the sample after step 1 for 60 s;

[0052] Step 3: Cool the sample after step 2 in water for 15 s;

[0053] Step 4: Repeat steps 2 and 3 20 times to obtain the final product.

[0054] like Figure 3 As shown, Figure 3 The microstructure of this embodiment after 20 times of electromagnetic induction treatment is shown in FIG. Figure 3 It can be seen that the low-magnification microstructure of the treated sample is different from the original state ( Figure 1 ) showed no significant difference, but the white precipitates in the high-magnification tissue increased significantly.

[0055] In this example, after 20 times of electromagnetic induction heating treatment, the hardness of the SLM GH4169 alloy is 326 HV, which is 22 HV higher than that of the original sample (304 HV).

[0056] Comparative Example 1

[0057] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 2 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0058] Step 2: electromagnetic induction heating the sample after step 1 for 600 s;

[0059] Step 3: Cool the sample after step 2 to room temperature to obtain the final product.

[0060] In this comparative example 1, after the SLM GH4169 alloy was directly subjected to electromagnetic induction heating for 600 s, the hardness was 293 HV, which was 11 HV lower than the original sample (304 HV). Compared with Example 2, it can be seen that under the same electromagnetic induction treatment time, due to the lack of repeated heating-cooling treatment, the hardness of the sample was not only not improved compared with the original state, but also decreased to a certain extent. It can be seen that repeated heating-cooling is important for this heat treatment method.

[0061] Comparative Example 2

[0062] Step 1: Place the GH4169 alloy sample prepared by selective laser melting at a distance of 2 mm from the electromagnetic induction coil and start electromagnetic induction heating treatment;

[0063] Step 2: electromagnetic induction heating the sample after step 1 for 200 s;

[0064] Step 3: Cool the sample after step 2 in water for 50 s;

[0065] Step 4: Repeat steps 2 and 3 for a total of 3 times to obtain the final product.

[0066] In this comparative example 2, after three electromagnetic induction heating treatments, the hardness of the SLM GH4169 alloy is 308 HV, which is 4 HV higher than the original sample (304 HV). Compared with Example 2, it can be seen that under the same electromagnetic induction treatment time, due to the reduction in the number of electromagnetic induction treatments, the hardness of the sample is only slightly higher than the original state. It can be seen that increasing the number of electromagnetic induction treatments is helpful to improve the hardness of the sample.

[0067] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for rapid stress relief of nickel-based alloys, characterized in that: The following steps are involved: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 30 s to 120 s; S2) cooling the nickel-based alloy after step S1) for 10 s to 60 s; S3) Repeat steps S1) and S2) at least 5 times.

2. The method according to claim 1, characterized in that In step S1), the electromagnetic induction heating treatment is performed using an electromagnetic induction coil, and the distance between the nickel-based alloy and the electromagnetic induction coil is 2 mm to 10 mm.

3. The method according to claim 1, characterized in that In step S1), the electromagnetic induction heating treatment time is 30 s to 60 s.

4. The method according to claim 1, characterized in that: In step S2), the cooling is water cooling, and the cooling time is 10 s to 30 s.

5. The method according to claim 1, characterized in that In step S2), the cooling is air cooling, and the cooling time is 30 s to 60 s.

6. The method according to claim 1, characterized in that In step S3), the number of repetitions is 5 to 40 times.

7. The method according to claim 6, characterized in that In step S3), the number of repetitions is 5 to 25 times.

8. The method according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 30 s to 40 s; S2) air cooling the nickel-based alloy after step S1) for 30 s to 40 s; S3) repeating step S1) and step S2) for 5 to 8 times); or, The method comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 50 s to 60 s; S2) air cooling the nickel-based alloy after step S1) for 50 s to 60 s; S3) repeating step S1) and step S2) for 13 to 17 times); or, The method comprises the following steps: S1) subjecting the nickel-based alloy to electromagnetic induction heating for 50 s to 60 s; S2) subjecting the nickel-based alloy after step S1) to water cooling for 10 s to 20 s; and S3) repeating step S1) and step S2) for 18 to 22 times.

9. The method according to claim 8, characterized in that In step S1), the nickel-based alloy is GH4169 alloy.

10. The method according to claim 8, characterized in that In step S1), the nickel-based alloy is a nickel-based alloy material obtained by 3D printing.

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