Preparation method of nickel-based alloy UNS7080

Abstract

The invention provides a preparation method of a nickel-based alloy UNS7080, which comprises the following steps of: 1, proportioning: calculating the raw material proportioning amount of each element of the alloy according to the mass ratio and the component control requirement of the UNS7080 alloy, and proportioning; secondly, the raw materials prepared in the first step are subjected to blank smelting; thirdly, the blank produced in the second step is subjected to cogging forging; fourthly, the blank forged in the third step is rolled; fifthly, the product rolled in the fourth step is subjected to heat treatment; sixthly, peeling, polishing and sawing the product subjected to heat treatment in the fifth step into sections; seventhly, UT flaw detection operation is conducted on the product treated in the sixth step; by adjusting the mass percent of elements in a formula contained in the preparation method and optimizing a heat treatment process, the hardness of a final finished product can be remarkably improved, and the high-hardness heat-resistant steel is more accepted and welcomed by the market and has good market and economic values.

Description

Technical Field

[0001] The present invention relates to the field of high-temperature alloys, and in particular to a method for preparing nickel-based alloy UNS7080. Background Art

[0002] UNS N07080 is a nickel-chromium-based precipitation-hardening, wrought-type high-temperature alloy. Its US designation is Nimonic alloy 80A, its UK counterpart is Nimonic 80A, and its Chinese counterpart is GH80A1. It is widely used in aerospace, energy, petrochemical, and other fields. In aerospace, it is used to manufacture engine rotor blades, guide vane supports, bolts, blade lock plates, and other parts. In the energy sector, it can be used in nuclear reactor fuel rods and solar water heaters. In the chemical industry, it is often used in refinery heating furnace tubes and chemical reactors.

[0003] The heat treatment process parameters (temperature, time, cooling rate, etc.) included in its manufacturing method have a significant impact on the structure and properties of the alloy. To obtain ideal performance, these parameters need to be precisely controlled, otherwise problems such as uneven structure and unstable performance may occur. In addition, different preparation processes and application requirements require corresponding adjustments to the heat treatment process, which increases the complexity of process development. Summary of the Invention

[0004] The present invention aims to provide a preparation method of nickel-based alloy UNS7080, and to improve the performance of the finished product by adjusting the formula and heat treatment process included in the preparation method.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing nickel-based alloy UNS7080 comprises the following steps:

[0007] Step 1: Batching: According to the UNS7080 alloy composition control requirements, calculate the raw material dosage of each element of the alloy according to the mass ratio and batch the ingredients;

[0008] Step 2: smelting the raw materials prepared in the first step into billets;

[0009] Step 3: Forging the blank produced in the second step;

[0010] Step 4: Rolling the billet after forging in the third step;

[0011] Step 5: Heat treat the product after the fourth step of rolling;

[0012] Step 6: Peel, polish and saw the product after the heat treatment in step 5 into sections;

[0013] The seventh step is to perform UT testing on the product processed in the sixth step.

[0014] In one embodiment, the raw material addition amount is: C≦0.10%, Mn≦1.0%, SI≦1.0%, S≦0.015%, Cr: 18.0-21.0%, Ti: 1.80-2.70%, Al: 0.50-1.80%, Fe≦3.0%, and the balance is Ni and other inevitable impurities.

[0015] In one embodiment, the raw material dosage is: C: 0.066%, Mn: 0.017%, SI: 0.017%, S: 0.0009%, Cr: 19.61%, Ti: 2.36%, Al: 1.32%, Fe: 0.62%, Ni: 75.8% and P: 0.001%.

[0016] In one embodiment, the billet smelting method includes vacuum induction melting and electroslag remelting.

[0017] In one embodiment, the rolling is performed by hot rolling and finishing rolling.

[0018] In one embodiment, the heat treatment method is solution heat treatment: 1046°C, hold for 8 hours, and air cool.

[0019] Compared with the prior art, the present invention has the following advantages or beneficial effects:

[0020] The present invention can significantly improve the hardness of the final product by adjusting the mass percentage of the elements in the formula included in the preparation method and optimizing the heat treatment process, thereby being more recognized and welcomed by the market and having good market and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A metallographic image of the nickel-based alloy prepared by the method provided by the present invention, magnified 100 times under a metallographic microscope;

[0022] Figure 2 The present invention provides a metallographic image of a nickel-based alloy prepared by the method of the present invention, obtained by magnifying the metallographic image 500 times under a metallographic microscope. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] Example

[0025] A method for preparing nickel-based alloy UNS7080 comprises the following steps:

[0026] Step 1: Batching: According to the UNS7080 alloy composition control requirements, calculate the raw material dosage of each element of the alloy according to the mass ratio and batch the ingredients;

[0027] Step 2: smelting the raw materials prepared in the first step into billets;

[0028] Step 3: Forging the blank produced in the second step;

[0029] Step 4: Rolling the billet after forging in the third step;

[0030] Step 5: Heat treat the product after the fourth step of rolling;

[0031] Step 6: Peel, polish and saw the product after the heat treatment in step 5 into sections;

[0032] Step 7: Perform UT testing on the product after step 6.

[0033] The raw material content is: C: 0.066%, Mn: 0.017%, SI: 0.017%, S: 0.0009%, Cr: 19.61%, Ti: 2.36%, Al: 1.32%, Fe: 0.62%, Ni: 75.8% and P: 0.001%;

[0034] Billet smelting methods include vacuum induction melting and electroslag remelting;

[0035] Vacuum induction melting (VIM) is a melting method that uses electromagnetic induction to generate eddy currents in a metal conductor to heat the charge under vacuum conditions. The chemical composition is controlled to the greatest extent possible to prevent the melt from coming into contact with hydrogen, oxygen, and nitrogen in the atmosphere. Electromagnetic stirring not only makes the melt uniform but also continuously brings reactants to the melt-vacuum interface, thereby enabling subsequent refining reactions to proceed smoothly. The volatilization and precipitation of gas content and non-metallic inclusions can significantly improve the mechanical properties of most high-temperature alloys.

[0036] Electro-Slag Remelting (ESR) utilizes the resistance heat generated by passing an electric current through molten slag as a heat source for smelting. Current is passed through a liquid slag pool, where the slag resists the heat, melting the metal electrodes. The molten metal forms droplets, which then fall through the slag layer into the molten metal pool. These droplets then crystallize and solidify into steel ingots in a water-cooled crystallizer. Electroslag metallurgy is currently an important method for producing high-quality materials. It combines high-temperature smelting, chemical refining, and cold crystallization to produce high-quality ingots with the advantages of high purity, low sulfur content, minimal non-metallic inclusions, a smooth ingot surface, uniform and dense crystals, and consistent metallographic structure and chemical composition.

[0037] The purpose of billet forging is to heat the billet to a certain temperature and, through forging, improve the internal structure of the metal, enhance its overall performance, and produce products with a certain shape. This provides billets for extrusion, rolling, and other processes, or produces finished products. Forging can break up coarse structures or inclusions with poor plasticity in the billet into fine structures, thereby improving the plasticity of the billet, reducing deformation resistance, and providing a fine-textured billet that is conducive to deformation for subsequent processing. Forging in a hot state allows smaller equipment to be used to achieve greater deformation.

[0038] The rolling is carried out by hot rolling and finishing.

[0039] Hot rolling can improve the processing performance of metals and alloys, that is, it can break up the coarse grains in the cast state, significantly improve the healing of edge lines, reduce or eliminate casting defects, transform the cast structure into a deformed structure, and improve the processing performance of the alloy.

[0040] Hot rolling usually uses large ingots and large reduction rolling, which not only improves production efficiency, but also creates conditions for increasing rolling speed and realizing continuous and automated rolling process.

[0041] The heat treatment method is solution heat treatment at 1046℃, maintaining for 8 hours, air cooling,

[0042] Then peel and remove the surface burrs, grind to a bright finish, and cut into sections at a fixed length;

[0043] Finally, 100% UT testing and level 2 acceptance are performed according to customer requirements.

[0044] Comparative Example 1

[0045] The adjusted formula ratio is: new material accounts for 70%, returned material accounts for 30%, and the adjusted raw material intake is: C: 0.057%, Ti: 1.85%, Ni: 76.319%; at the same time, the solution heat treatment temperature is 1066°C, and the others are consistent with Example 1.

[0046] Comparative Example 2

[0047] The adjusted formula ratio is: new material accounts for 80%, returned material accounts for 20%, and the adjusted raw material intake is: C: 0.047%, Ti: 1.85%, Ni: 76.329%; at the same time, the solution heat treatment temperature is 1066°C, and the others are consistent with Example 1.

[0048] Comparative Example 3

[0049] The solution heat treatment temperature was adjusted to 1066°C, and the other conditions were the same as in Example 1.

[0050] The following table shows the test data of Examples and Comparative Examples:

[0051] Example Sample number Proportion of waste materials C％ Ti% Solution annealing temperature Hardness HRC inclusions 500x metallographic Comparative Example 1 AL-24-01 30％ 0.057 1.85％ 1066 36 4 types of inclusions Continuous status quo precipitates Comparative Example 2 AL-24-02 20％ 0.047 1.85％ 1066 35 4 types of inclusions Continuous status quo precipitates Comparative Example 3 AL-24-03 0％ 0.066 2.36％ 1066 38 No inclusions mixed crystal Example AL-24-04 0％ 0.066 2.36％ 1046 38 No inclusions Grain size 5.5

[0052] The data in the above table and the attached Figure 1 and 2 It can be concluded that the strength of the nickel-based alloy in the embodiment prepared by the preparation method provided by the present invention is significantly improved compared with the strength of other comparative examples, and at the same time has the advantages of being free of inclusions and being able to reach a grain size of 5.5.

[0053] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive in all respects. The scope of the present invention is defined by the appended claims rather than the foregoing description, and all changes that come within the meaning and range of equivalents of the claims are intended to be included therein.

[0054] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing nickel-based alloy UNS7080, characterized in that: The following steps are involved: first step: Batching: According to the UNS7080 alloy composition control requirements, the raw material dosage of each element of the alloy is calculated according to the mass ratio and the batching is carried out; Step 2: smelting the raw materials prepared in the first step into billets; Step 3: Forging the blank produced in the second step; Step 4: Rolling the billet after forging in the third step; Step 5: Heat treat the product after the fourth step of rolling; Step 6: Peel, polish and saw the product after the heat treatment in step 5 into sections; The seventh step is to perform UT testing on the product processed in the sixth step.

2. The method for preparing a nickel-based alloy UNS7080 according to claim 1, characterized in that: The raw material addition amounts are: C≦0.10%, Mn≦1.0%, SI≦1.0%, S≦0.015%, Cr: 18.0-21.0%, Ti: 1.80-2.70%, Al: 0.50-1.80%, Fe≦3.0%, and the balance is Ni and other inevitable impurities.

3. The method for preparing a nickel-based alloy UNS7080 according to claim 2, characterized in that: The raw material addition amounts are: C: 0.066%, Mn: 0.017%, SI: 0.017%, S: 0.0009%, Cr: 19.61%, Ti: 2.36%, Al: 1.32%, Fe: 0.62%, Ni: 75.8% and P: 0.001%.

4. The method for preparing a nickel-based alloy UNS7080 according to claim 1, characterized in that: The billet smelting methods include vacuum induction melting and electroslag remelting.

5. The method for preparing nickel-based alloy UNS7080 according to claim 1, characterized in that: The rolling is performed by hot rolling and finishing.

6. The method for preparing nickel-based alloy UNS7080 according to claim 1, characterized in that: The heat treatment method is solution heat treatment: 1046°C, holding for 8 hours, and air cooling.

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