A high and low temperature treatment method for improving the wear resistance of nickel-based high temperature alloy finished products

Abstract

The present invention discloses a high and low temperature treatment method for improving the wear resistance of a finished nickel-based high-temperature alloy. The method comprises homogenizing the nickel-based high-temperature alloy ingot, hot blanking, annealing, finished product processing, cyclic low-temperature treatment, oxidation treatment, and cyclic low-temperature treatment again. The treatment method of the present invention has a simple device, a simple process, and a low cost. It is suitable for nickel-based high-temperature alloy products of various sizes and shapes. The hardness of the nickel-based high-temperature alloy can be significantly improved by the treatment method of the present invention, and spinel oxide with excellent wear resistance can be generated, thereby effectively improving the wear resistance of the nickel-based high-temperature alloy product.

Description

Technical Field

[0001] The present invention relates to the technical field of material processing, and particularly relates to a high and low temperature treatment method for improving the wear resistance of nickel-based superalloy finished products. Background Art

[0002] Nickel-based superalloys are very promising high-temperature application materials. Due to their high high-temperature strength, good corrosion resistance, and excellent comprehensive properties such as fatigue, fracture toughness, and plasticity, they are widely used in manufacturing components of aerospace, marine, and transportation engines. However, when nickel-based superalloys are in service in the above fields, friction and wear problems will inevitably occur, which greatly reduces the performance and safety reliability of workpieces. In addition, these key components will also be tested by complex external factors such as high temperature, high speed, high load, and corrosion during service, thus increasing the difficulty of improving the wear resistance of nickel-based superalloys. How to improve the friction and wear performance of nickel-based superalloys through strengthening technologies has attracted the attention of many researchers. Of course, this is also the only way to promote the development of nickel-based superalloys.

[0003] Currently, there are numerous existing technologies and methods for improving the wear resistance of nickel-based superalloys, such as wide-temperature-range low-friction coatings, surface nitriding / carbonizing, surface plastic deformation strengthening and other strengthening technologies. Although these technologies and methods have strengthened the wear resistance of nickel-based superalloys in a certain service environment, they all have problems such as unstable strengthening layers and weak bonding. More importantly, these strengthening processes are complex and consume a large amount of manpower and material resources, ultimately greatly increasing the manufacturing cost. On the other hand, when the above strengthening technologies are applied to complex-structured products of nickel-based superalloys, such as bent pipes and closed-cavity parts, the prior art cannot uniformly treat their surfaces. Summary of the Invention

[0004] In order to solve the above-mentioned deficiencies existing in the prior art, the purpose of the present invention is to provide a high and low temperature treatment method for improving the wear resistance of nickel-based superalloy finished products, so as to solve the problems of unstable strengthening layers, complex strengthening processes, high costs, and difficulty in strengthening complex-structured components in the prior art.

[0005] The technical solution of the present invention for solving the above technical problems is as follows:

[0006] A high and low temperature treatment method for improving the wear resistance of nickel-based superalloy finished products, comprising the following steps:

[0007] (1) Cyclic low temperature treatment: subjecting the nickel-based superalloy product to low temperature treatment, returning to room temperature state after the treatment is completed, and then performing low temperature treatment again, wherein the low temperature treatment temperature is 60 - 120 °C, and the treatment time is 20 - 60 h;

[0008] (2) Oxidation treatment: The nickel-based superalloy product after the cyclic low-temperature treatment in step (1) is subjected to oxidation treatment, where the oxidation treatment temperature is 500 - 700 °C and the treatment time is 2.5 - 3.5 h;

[0009] (3) Repeated cyclic low-temperature treatment: The nickel-based superalloy product after the oxidation treatment in step (2) is subjected to repeated cyclic low-temperature treatment, and the treatment conditions are the same as those in step (1).

[0010] Preferably, in step (1), the low-temperature treatment temperature is 120 °C and the treatment time is 48 h.

[0011] Preferably, in step (3), the oxidation treatment temperature is 700 °C and the treatment time is 3 h.

[0012] Furthermore, the preparation method of the above nickel-based superalloy product includes the following steps:

[0013] (a) Vacuum smelt a nickel-based superalloy ingot;

[0014] (b) Homogenize the nickel-based superalloy ingot smelted in step (a) to eliminate low-melting-point phases and harmful phases;

[0015] (c) Perform hot cogging on the nickel-based superalloy ingot after homogenization treatment in step (b) to obtain a blank;

[0016] (d) Perform vacuum annealing on the blank obtained in step (c);

[0017] (e) Process the blank after vacuum annealing in step (d) to obtain a nickel-based superalloy product.

[0018] Furthermore, the gas content of the above nickel-based superalloy ingot: oxygen ≤ 80 ppm, nitrogen ≤ 80 ppm, inclusions < grade 2.

[0019] Furthermore, the specific steps of the homogenization treatment in step (b) include: first holding the nickel-based superalloy ingot at 1100 - 1200 °C for 8 - 12 h, and then holding it at 1200 - 1300 °C for 40 - 50 h.

[0020] Preferably, the nickel-based superalloy ingot is first held at 1140 °C for 10 h, and then held at 1210 °C for 48 h.

[0021] Furthermore, the hot cogging treatment temperature in step (c) is 1000 - 1300 °C.

[0022] Furthermore, the specific method of the vacuum annealing treatment in step (d) includes: first heating to 800 - 1000 °C, then holding in vacuum for 2 - 5 h, and finally cooling to room temperature.

[0023] Furthermore, in the cyclic low-temperature treatment of steps (1) and (2), the number of low-temperature treatment times is not less than 2 times.

[0024] The finished nickel-based superalloy product prepared by the above treatment method.

[0025] The present invention has the following beneficial effects:

[0026] (1) In the present invention, the cyclic low-temperature treatment plays a role in refining grains and increasing the grain boundary density, thereby improving the hardness of the nickel-based superalloy and increasing the channels for spinel oxidation; during the subsequent high-temperature oxidation process, the high-density grain boundaries promote the oxidation reaction and generate more spinel oxides; in order to avoid grain growth during the high-temperature oxidation process, the nickel-based superalloy product after high-temperature oxidation is subjected to cyclic low-temperature treatment again, so as to refine grains again, which can significantly improve the hardness of the nickel-based superalloy and generate spinel oxides with excellent wear resistance, effectively improving the wear resistance of the nickel-based superalloy product.

[0027] (2) The treatment method of the present invention has a simple device, a simple process, and low cost, and is suitable for nickel-based superalloy products of various sizes and shapes. Description of the Drawings

[0028] Figure 1 It is a Zeiss optical microscope photograph of Test Example 1, where (a) is an extruded pipe, (b) is a pipe after one low-temperature treatment, and (c) is a pipe after two low-temperature treatments;

[0029] Figure 2 It is a scanning electron microscope photograph of Test Example 2, where (a) is a pipe without low-temperature treatment, and (b) is a pipe after two low-temperature treatments;

[0030] Figure 3 It is a Raman peak diagram of Test Example 2;

[0031] Figure 4 It is a surface morphology photograph of the sample after the wear test of Test Example 3, where (a) is an untreated pipe, and (b) is a pipe after the final treatment. Detailed Embodiments

[0032] The following examples are only used to explain the present invention and are not intended to limit the scope of the present invention. For those not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0033] Example 1:

[0034] A high-low temperature treatment method for improving the wear resistance of nickel-based superalloys, comprising the following steps:

[0035] (1) Use a qualified Inconel 625 nickel-based superalloy ingot produced by vacuum smelting as the processing material;

[0036] (2) First, keep the Inconel 625 nickel-based superalloy at 1140 °C for 10 h, and then at 1210 °C for 48 h for homogenization treatment to eliminate microsegregation and harmful phases;

[0037] (3) Forge and break the billet of the Inconel 625 nickel-based superalloy after the homogenization treatment in step (2) at 1180 °C to refine the homogeneous structure and obtain a blank;

[0038] (4) Process the blank obtained in step (3) by machining to produce a hot extrusion blank;

[0039] (5) Hot extrude the hot extrusion blank obtained in step (4) under the conditions of an extrusion temperature of 1150 °C, an extrusion speed of 45 mm / s, and an extrusion ratio of 8 to obtain an extruded tube;

[0040] (6) Keep the extruded tube obtained in step (5) at 1050 °C for 1 h for solution treatment, then pickling to remove the surface lubricant, and straightening treatment to obtain a straightened tube;

[0041] (7) Perform cold rolling and heat treatment on the straightened tube obtained in step (6) to produce a nickel-based superalloy tube product;

[0042] (8) Place the nickel-based superalloy tube product obtained in step (7) in a low-temperature environmental chamber for low-temperature treatment, with a treatment temperature of 120 °C and a treatment time of 48 h;

[0043] (9) Restore the nickel-based superalloy tube product after the low-temperature treatment in step (8) to room temperature in the room temperature, and then place it in a low-temperature environmental chamber for low-temperature treatment, with a treatment temperature of 120 °C and a treatment time of 48 h to complete one cycle of low-temperature treatment;

[0044] (10) Perform oxidation treatment on the nickel-based superalloy tube product after the cyclic low-temperature treatment in step (9), with a treatment temperature of 700 °C and a treatment time of 3 h.

[0045] (11) Repeat step (8) and step (9) once, and perform cyclic low-temperature treatment on the nickel-based superalloy tube product after the oxidation treatment in step (10) to obtain the finally processed nickel-based superalloy tube product.

[0046] Example 2:

[0047] A high and low temperature treatment method for improving the wear resistance of nickel-based superalloys, comprising the following steps:

[0048] (1) Use a qualified Inconel 625 nickel-based superalloy ingot produced by vacuum smelting as the processing material;

[0049] (2) First, keep the Inconel 625 nickel-based superalloy at 1100 °C for 10 h, and then at 1250 °C for 40 h for homogenization treatment to eliminate microsegregation and harmful phases;

[0050] (3) Forge and bloom the Inconel 625 nickel-based superalloy after the homogenization treatment in step (2) at 1100 °C to refine the homogeneous structure and obtain a billet;

[0051] (4) Machine-process the billet obtained in step (3) to produce a hot extrusion billet;

[0052] (5) Perform hot extrusion on the hot extrusion billet obtained in step (4) under the conditions of an extrusion temperature of 1150 °C, an extrusion speed of 45 mm / s, and an extrusion ratio of 8 to obtain an extruded pipe;

[0053] (6) Subject the extruded pipe obtained in step (5) to solution treatment by keeping it at 1050 °C for 1 h, then pickling to remove the surface lubricant, and straightening to obtain a straightened pipe;

[0054] (7) Perform cold rolling and heat treatment on the straightened pipe obtained in step (6) to produce a nickel-based superalloy pipe product;

[0055] (8) Place the nickel-based superalloy pipe product obtained in step (7) in a low-temperature environmental chamber for low-temperature treatment at a treatment temperature of 100 °C and a treatment time of 55 h;

[0056] (9) Let the nickel-based superalloy pipe product after the low-temperature treatment in step (8) return to room temperature in the room, and then place it in a low-temperature environmental chamber for low-temperature treatment at a treatment temperature of 100 °C and a treatment time of 55 h to complete one cycle of low-temperature treatment;

[0057] (10) Perform oxidation treatment on the nickel-based superalloy pipe product after the cyclic low-temperature treatment in step (9) at a treatment temperature of 500 °C and a treatment time of 3.5 h.

[0058] (11) Repeat step (8) and step (9) once, and perform cyclic low-temperature treatment on the nickel-based superalloy pipe product after the oxidation treatment in step (10) to obtain the finally processed nickel-based superalloy pipe product.

[0059] Example 3:

[0060] A high-low temperature treatment method for improving the wear resistance of nickel-based superalloys, comprising the following steps:

[0061] (1) Use a qualified Inconel 625 nickel-based superalloy ingot produced by vacuum melting as the processing material;

[0062] (2) First, keep the Inconel 625 nickel-based superalloy at 1200 °C for 8 h, and then at 1300 °C for 50 h for homogenization treatment to eliminate microsegregation and harmful phases;

[0063] (3) Forge and bloom the Inconel 625 nickel-based superalloy after the homogenization treatment in step (2) at 1300 °C to refine the uniform structure and obtain a billet;

[0064] (4) Process the billet obtained in step (3) by machining to obtain a hot extrusion billet;

[0065] (5) Perform hot extrusion on the hot extrusion billet obtained in step (4) under the conditions of an extrusion temperature of 1150 °C, an extrusion speed of 45 mm / s, and an extrusion ratio of 8 to obtain an extruded pipe;

[0066] (6) Keep the extruded pipe obtained in step (5) at 1050 °C for 1 h for solution treatment, then pickling to remove the surface lubricant, and perform straightening treatment to obtain a straightened pipe;

[0067] (7) Perform cold rolling and heat treatment on the straightened pipe obtained in step (6) to produce a nickel-based superalloy pipe product;

[0068] (8) Place the nickel-based superalloy pipe product obtained in step (7) in a low-temperature environmental chamber for low-temperature treatment, with a treatment temperature of 90 °C and a treatment time of 40 h;

[0069] (9) Let the nickel-based superalloy pipe product after the low-temperature treatment in step (8) return to room temperature in the room temperature, and then place it in a low-temperature environmental chamber for low-temperature treatment again, with a treatment temperature of 90 °C and a treatment time of 40 h to complete one cycle of low-temperature treatment;

[0070] (10) Perform oxidation treatment on the nickel-based superalloy pipe product after the cyclic low-temperature treatment in step (9), with a treatment temperature of 600 °C and a treatment time of 2.5 h.

[0071] (11) Repeat step (8) and step (9) once, and perform cyclic low-temperature treatment on the nickel-based superalloy pipe product after the oxidation treatment in step (10) to obtain the finally treated nickel-based superalloy pipe product.

[0072] Test Example 1:

[0073] Take the extruded pipe obtained in step (4) of Example 1, the pipe after one low-temperature treatment obtained in step (8), and the pipe after two low-temperature treatments obtained in step (9), and process them respectively using a wire electrical discharge machine to cut out squares of 10×10×5 mm for metallographic structure observation. The metallographic structure was photographed using a Zeiss optical microscope as shown in Figure 1 shown.

[0074] From Figure 1 the results, it can be seen that the original structure without low-temperature treatment is equiaxed grains and a large number of annealing twins. In the structure after one low-temperature treatment, the grains in some regions are refined, and the twin boundaries also increase. In the structure after two low-temperature treatments, the grains are basically all refined, effectively increasing the grain boundary density.

[0075] Test Example 2:

[0076] Take the pipe that has not been low-temperature treated in step (7) of Example 1 and the pipe after two low-temperature treatments obtained in step (9), hold them at 700 °C for 3 h for high-temperature oxidation, and observe their oxidized surfaces using a scanning electron microscope. The test results are as shown in Figure 2 shown, and Raman spectroscopy analysis was carried out. The obtained Raman peak diagram is as shown in Figure 3 shown.

[0077] From Figure 2 it can be observed that spinel oxides (Raman shift value in the range of 650 - 700 cm -1 ) are formed on the surfaces of both the pipe without low-temperature treatment and the pipe after two low-temperature treatments. However, the spinel oxides on the surface of the pipe after cyclic low-temperature treatment are significantly denser.

[0078] From Figure 3 it can be observed that the spinel oxide peak on the surface of the nickel-based superalloy pipe after two low-temperature treatments is stronger, which also indicates that relatively more oxides are formed. The surface microhardness of the nickel-based superalloy pipe after two low-temperature treatments and high-temperature oxidation was tested, and the results showed that the hardness value reached 320 HV.

[0079] Test Example 3:

[0080] Take the pipe that has not been low-temperature treated in step (7) and the nickel-based superalloy pipe product finally processed in step (11) for testing. Use a high-temperature friction and wear testing machine to conduct a friction and wear test at 500 °C (friction parameters: Si 3 N 4 friction pair, 20 N, 1 m / s, 15 min). The results are shown in Table 1, and the friction morphology was observed using a scanning electron microscope. The results are as shown in Figure 4 shown.

[0081] Table 1 Friction and Wear Test

[0082] Average friction coefficient <![CDATA[Wear rate mm -3 / (N·m)]]> Pipe without low-temperature treatment 0.33 <![CDATA[5.7×10 -5 > Final processed nickel-based superalloy pipe product 0.24 <![CDATA[4.1×10 -5 >

[0083] It can be seen from the data in Table 1 that both the average friction coefficient and the wear rate of the nickel-based superalloy tube products processed by the method of the present invention have been significantly reduced. Figure 4 It can be found from the shown morphological features that the worn surface of the nickel-based superalloy tube products processed by the method of the present invention is relatively flat and the surface material spalling is relatively light. The test results show that the processing method of the present invention effectively improves the wear resistance of the nickel-based superalloy.

[0084] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy, characterized in that: The following steps are involved: (1) Cyclic low temperature treatment: The nickel-based high temperature alloy product is subjected to low temperature treatment, and then restored to room temperature after the treatment, and then subjected to low temperature treatment again, wherein the low temperature treatment temperature is 60-120°C and the treatment time is 20-60h; (2) oxidation treatment: subjecting the nickel-based high-temperature alloy product after the cyclic low-temperature treatment in step (1) to oxidation treatment, wherein the oxidation treatment temperature is 500-700° C. and the treatment time is 2.5-3.5 h; (3) Re-circulating low temperature treatment: the nickel-based high temperature alloy product after oxidation treatment in step (2) is subjected to re-circulating low temperature treatment under the same treatment conditions as step (1); In the step (1) and the step (3), the number of low-temperature treatments in the cyclic low-temperature treatment is no less than 2 times.

2. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 1, characterized in that: The low temperature treatment temperature in step (1) is 120°C and the treatment time is 48h.

3. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 1, characterized in that: The oxidation treatment temperature in step (2) is 700° C. and the treatment time is 3 h.

4. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 1, characterized in that: The method for preparing the nickel-based high-temperature alloy product comprises the following steps: (a) Vacuum smelting of nickel-based high-temperature alloy ingots; (b) homogenizing the nickel-based high-temperature alloy ingot smelted in step (a) to eliminate low melting point phases and harmful phases; (c) subjecting the nickel-based high-temperature alloy ingot subjected to the homogenization treatment in step (b) to a hot blanking treatment to obtain a blank; (d) subjecting the blank obtained in step (c) to vacuum annealing; (e) Processing the blank after vacuum annealing in step (d) to obtain a nickel-based high-temperature alloy product.

5. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 4, characterized in that: The gas content of the nickel-based high-temperature alloy ingot is: oxygen ≤80ppm, nitrogen ≤80ppm, and inclusions <level 2.

6. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 4, characterized in that: The specific steps of the homogenization treatment in step (b) include: firstly subjecting the nickel-based high-temperature alloy ingot to a heat preservation treatment at 1100-1200° C. for 8-12 hours, and then subjecting the nickel-based high-temperature alloy ingot to a heat preservation treatment at 1200-1300° C. for 40-50 hours.

7. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 4, characterized in that: The hot blanking treatment temperature in step (c) is 1000-1300°C.

8. The high and low temperature treatment method for improving the wear resistance of a finished nickel-based high temperature alloy according to claim 4, characterized in that: The vacuum annealing treatment in step (d) specifically includes: first heating to 800-1000° C., then keeping the temperature under vacuum for 2-5 hours, and finally cooling to room temperature.

9. A nickel-based high-temperature alloy product obtained by the treatment method according to any one of claims 1 to 8.

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