Homogenized high-temperature alloy blank forming method

Abstract

The invention belongs to the technical field of metal materials, and particularly relates to a homogenized high-temperature alloy blank forming method. The homogenized high-temperature alloy blank forming method comprises metal surface treatment, and the metal surface treatment comprises the following steps that (1) a metal plate blank is subjected to surface pretreatment and then connected with the positive electrode of a power source, and a conductor plate is connected with the negative electrode of the power source; (2) immersing the metal plate blank and the conductor plate into an acidic electrolyte for electrolytic treatment; the voltage of the electrolytic treatment is 20-30 V, the current of the electrolytic treatment is 200-350 A, the temperature of the electrolytic treatment is 20-30 DEG C, and the time of the electrolytic treatment is 1.5-2.5 h; and (3) after the electrolytic treatment is finished, the surface of the metal plate blank is subjected to acid pickling treatment.

Description

Technical Field

[0001] The invention belongs to the technical field of metal materials, and in particular relates to a homogenized high-temperature alloy blank forming method. Background Art

[0002] Large forgings are core components of major equipment and play an indispensable role in national security and the national economy. Large forgings are often made from hundred-ton ingots. Due to the size effect of the metal solidification process, defects such as macrosegregation, shrinkage and looseness often exist inside the large ingots, which seriously affect the quality of forgings. This has become a global problem. The Institute of Metal Research, Chinese Academy of Sciences, was the first in the world to invent metal construction forming technology. This technology uses multiple small-sized homogenized slabs as primitives, and through surface activation, vacuum packaging, high-temperature deformation and other means, the construction interface is completely consistent with the matrix in terms of organization and performance, thereby obtaining the homogenized parent material required for large forgings, realizing a new type of manufacturing that "makes small things big".

[0003] High-temperature alloys are widely used in aerospace, petrochemical, ocean-going ships and other fields due to their excellent high-temperature performance. With the rapid development of science and technology and industry technology, more and more stringent requirements are placed on the performance of high-temperature alloys. In addition to the requirements for higher temperatures and more excellent performance, there is also a great demand for larger-sized components. However, due to the high degree of alloying, the serious size effect greatly limits the size of high-temperature alloy components. The application of metal construction forming technology in the preparation of large-sized high-temperature alloy components has great potential.

[0004] Typical construction steps include surface treatment of small-sized slabs, vacuum packaging, and high-temperature large deformation. A large number of laboratory and industrial-level construction tests have been carried out for different materials. Relevant research results show that achieving mutual contact between fresh metal surfaces during the construction process is the most important prerequisite and an extremely critical step. Therefore, more and more technicians are committed to the research of surface treatment technology. Summary of the invention

[0005] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0006] The current mainstream material surface treatment methods include milling, mechanical grinding and pickling. Milling can be divided into two types: with coolant and without coolant. Coolant will introduce contamination to the fresh metal surface milled, while milling without coolant usually causes surface oxidation due to local temperature rise, and the surface flatness is poor. Surface oxides can be effectively removed by mechanical grinding or chemical pickling after milling, but milling and mechanical grinding are prone to produce stress layers. Ordinary chemical pickling cannot completely remove surface milling marks and stress layers because the surface reaction layer is small and the oxide film formed on the surface will hinder the reaction of the matrix. A large number of studies have shown that surface oxides will hinder the bonding of the interface, and the stress layer will also affect the dynamic recrystallization and recovery process around the interface, which is not conducive to the complete healing of the interface. The current mainstream material surface treatment methods cannot completely achieve the complete removal of surface oxides and stress layers at the same time. For the construction and forming process, requirements are put forward for new surface treatment methods that can achieve these two goals.

[0007] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention provides a homogenized high-temperature alloy billet forming method, which includes metal surface treatment, wherein the surface treatment method uses an electrochemical corrosion method to remove the original surface metal oxide and surface metal, and the surface layer removal thickness is greater than the ordinary chemical pickling process, and no stress layer generated by mechanical grinding or the like is generated. At this time, the surface is a fresh base metal without residual stress.

[0008] The homogenized high-temperature alloy billet forming method according to the embodiment of the present invention comprises metal surface treatment, wherein the metal surface treatment comprises the following steps:

[0009] (1) After surface pretreatment, the metal sheet blank is connected to the positive electrode of the power supply, and the conductor plate is connected to the negative electrode of the power supply;

[0010] (2) immersing the metal sheet blank and the conductor plate described in step (1) in an acidic electrolyte for electrolytic treatment; the voltage of the electrolytic treatment is 20 to 30 V, the current of the electrolytic treatment is 200 to 350 A, the temperature of the electrolyte during the electrolytic treatment is 20 to 30° C., and the electrolytic treatment time is 1.5 to 2.5 h;

[0011] (3) After the electrolytic treatment in step (2) is completed, the surface of the metal sheet is pickled.

[0012] The advantages and technical effects brought by the homogenized high-temperature alloy billet forming method of the embodiment of the present invention are as follows: 1. The method of the embodiment of the present invention adopts an electrolytic treatment method to remove the original surface metal oxide and the surface metal. The thickness of the surface removed is greater than that of the ordinary chemical pickling process, and no stress layer generated by mechanical grinding or the like is generated, thereby obtaining a fresh base metal surface without residual stress; 2. The method of the embodiment of the present invention continues to perform pickling treatment after the electrolytic treatment to clean the surface reaction products and the surface oxides generated by electrolysis, so that the fresh base without residual stress is completely exposed, and the base performance can be better restored during the construction and forming process; 3. The method of the embodiment of the present invention adopts a small voltage and a large current method to carry out the electrolytic process, which can not only ensure the safety during the operation, but also is more conducive to obtaining a fresh base metal surface with uniform and smooth electrolysis; 4. The method of the embodiment of the present invention is simple and easy to operate, has a good implementation effect, and is convenient for promotion and application in industrial production.

[0013] In some embodiments, in step (1), the surface pretreatment includes first milling or mechanically grinding the surface of the metal sheet blank, and then cleaning the surface of the metal sheet blank with a cleaning liquid; the cleaning liquid includes at least one of water or alcohol.

[0014] In some embodiments, in step (1), the conductor plate includes at least one of a lead plate, a platinum plate or a copper plate.

[0015] In some embodiments, in step (2), the acidic electrolyte includes at least one of hydrofluoric acid, phosphoric acid, boric acid, sulfuric acid, hydrochloric acid or perchloric acid.

[0016] In some embodiments, in step (2), the conductor plate is placed directly in front of the surface to be processed of the metal sheet blank, and the projection of the conductor plate on the surface to be processed completely covers the surface to be processed.

[0017] In some embodiments, in step (2), a distance of 15 to 20 cm is maintained between the conductor plate and the metal sheet blank.

[0018] In some embodiments, the step (3) further includes performing a first cleaning treatment before the pickling treatment, and performing a second cleaning treatment and a drying treatment after the pickling treatment.

[0019] In some embodiments, the cleaning solution used in the first cleaning process and / or the second cleaning process includes at least one of water or alcohol.

[0020] In some embodiments, a brush is used for cleaning during the pickling process, and the pickling time is between 30 and 60 seconds;

[0021] In some embodiments, the pickling solution used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid or hydrofluoric acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of the power source, metal sheet blank and conductor plate in the electrolysis process;

[0023] Figure 2 is the surface of the metal blank after treatment in Example 1;

[0024] Figure 3 The surface of the metal blank after treatment in Comparative Example 1;

[0025] Figure 4 This is the surface of the metal blank after being treated in Comparative Example 2. DETAILED DESCRIPTION

[0026] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0027] The homogenized high-temperature alloy billet forming method according to the embodiment of the present invention comprises metal surface treatment, wherein the metal surface treatment comprises the following steps:

[0028] (1) After surface pretreatment, the metal sheet blank is connected to the positive electrode of the power supply, and the conductor plate is connected to the negative electrode of the power supply;

[0029] (2) immersing the metal sheet blank and the conductor plate described in step (1) in an acidic electrolyte for electrolytic treatment; the voltage of the electrolytic treatment is 20 to 30 V, the current of the electrolytic treatment is 200 to 350 A, the temperature of the electrolyte during the electrolytic treatment is 20 to 30° C., and the electrolytic treatment time is 1.5 to 2.5 h;

[0030] (3) After the electrolytic treatment in step (2) is completed, the surface of the metal sheet is pickled.

[0031] The homogenized high-temperature alloy billet forming method of the embodiment of the present invention adopts electrolytic treatment to remove the original surface metal oxide and surface metal. The thickness of the surface layer removed is greater than that of the ordinary chemical pickling process, and no stress layer generated by mechanical grinding or the like is generated, thereby obtaining a fresh base metal surface without residual stress; after the electrolytic treatment, the pickling treatment is continued to be performed to clean the surface reaction products and the surface oxides generated by electrolysis, so that the fresh base without residual stress is completely exposed, and the base performance can be better restored during the construction and forming process; the electrolytic process is carried out in a small voltage and large current manner, which can not only ensure the safety during the operation, but also is more conducive to obtaining a fresh base metal surface that is uniform and flat by electrolysis; the method is simple and easy to operate, has a good implementation effect, and is convenient for promotion and application in industrial production.

[0032] In some embodiments, preferably, in the step (1), the surface pretreatment includes first milling or mechanically grinding the surface of the metal sheet blank, and then cleaning the surface of the metal sheet blank with a cleaning liquid; the cleaning liquid includes at least one of water or alcohol.

[0033] In the embodiment of the present invention, the surface of the metal sheet blank is cleaned to remove dust, oil stains, etc. covering the surface of the metal sheet blank, thereby ensuring that the stains on the surface of the metal sheet blank will not affect the electrolytic treatment process.

[0034] In some embodiments, preferably, in step (1), the metal sheet blank is connected to the positive electrode of the power source by welding, overlapping or clamping. In order to ensure uniform electrolysis of the surface of the metal blank, multiple wires are drawn from the positive electrode and connected to the side of the surface of the metal blank to be processed, and are symmetrically distributed; the side of the surface of the metal blank to be processed can also be completely surrounded by wires or electrode plates.

[0035] In some embodiments, preferably, in step (1), the conductor plate comprises at least one of a lead plate, a platinum plate or a copper plate. Further preferably, the conductor plate is a single inactive metal plate, or a plurality of inactive metal plates extending from the negative pole of the power supply.

[0036] In the embodiment of the present invention, when the conductor plates are multiple inactive metal plates led from the negative electrode of the power supply, the electrolytic treatment of the surface of a larger metal sheet blank or multiple surfaces of a metal sheet blank can be achieved. Considering the uniformity and practical feasibility of electrolysis, the two opposite surfaces of the metal sheet blank are electrolyzed once, and the non-electrolytic surface will also be electrolyzed to a certain extent during the actual electrolysis process, but due to the clamping or fixing of the electrode, the non-electrolytic surface cannot be electrolyzed uniformly and effectively.

[0037] In some embodiments, preferably, in step (2), the acidic electrolyte comprises at least one of hydrofluoric acid, phosphoric acid, boric acid, sulfuric acid, hydrochloric acid or perchloric acid. Further preferably, the concentration of the acidic electrolyte is 10-30%.

[0038] like Figure 1 As shown, in some embodiments, preferably, in step (2), the conductor plate is placed in front of the surface to be processed of the metal sheet blank, and the projection of the conductor plate on the surface to be processed completely covers the surface to be processed. Further preferably, in step (2), a distance of 15 to 20 cm is maintained between the conductor plate and the metal sheet blank.

[0039] In some embodiments, preferably, the step (3) further includes performing a first cleaning treatment before the pickling treatment, and performing a second cleaning treatment and a drying treatment after the pickling treatment.

[0040] In some embodiments, preferably, the cleaning solution used in the first cleaning process and / or the second cleaning process includes at least one of water or alcohol.

[0041] In some embodiments, preferably, a brush is used for cleaning during the pickling process, and the time of the pickling process is between 30 and 60 seconds.

[0042] In some embodiments, preferably, the pickling solution used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid or hydrofluoric acid.

[0043] The technical solution of the present invention is described in detail below in conjunction with specific embodiments and drawings.

[0044] Example 1

[0045] (1) After mechanical grinding, the surface of the GH4169 alloy slab is cleaned with clean water to remove dust, oil and other stains on the surface of the metal slab;

[0046] (2) connecting the GH4169 alloy slab to the positive electrode of the power supply by welding, and connecting the conductor plate to the negative electrode of the power supply by welding, wherein the conductor plate is a lead plate;

[0047] (3) completely immersing the GH4169 alloy slab and the conductor plate in a 25% sulfuric acid solution for electrolytic treatment, wherein the voltage of the electrolytic treatment is 25 V, the current of the electrolytic treatment is 280-300 A, the temperature of the electrolytic treatment is 24-26° C., and the time of the electrolytic treatment is 2 h;

[0048] (4) After the electrolytic treatment, the surface of the GH4169 alloy slab is cleaned with clean water for the first time, and then the GH4169 alloy slab is placed in a mixed acid solution of hydrochloric acid and sulfuric acid, and cleaned with a brush for about 50 seconds. Then, the surface of the GH4169 alloy slab is cleaned with clean water for the second time, and then blown dry and stored.

[0049] The surface of the GH4169 alloy slab after treatment in this embodiment is as shown in the attached Figure 2 As shown, from Figure 2 It can be seen that the electrolysis treatment + pickling treatment and the control of the electrolysis parameters are within the appropriate range, and there are no obvious knife marks and processing marks on the metal surface.

[0050] Comparative Example 1

[0051] The treatment method of this comparative example is the same as that of Example 1, except that in step (2), the temperature of the electrolytic treatment is 15°C.

[0052] The surface of the GH4169 alloy slab after the comparative example treatment is as shown in the attached Figure 3 As shown, from Figure 3 It can be seen that the surface of the metal sheet is obviously insufficiently electrolyzed, and there are knife marks and grinding marks. This is because the temperature is low during the electrolytic treatment, resulting in a slow reaction in the initial stage.

[0053] Comparative Example 2

[0054] The treatment method of this comparative example is the same as that of Example 1, except that in step (2), the temperature of the electrolytic treatment is 35°C.

[0055] The surface of the GH4169 alloy slab after the comparative example treatment is as shown in the attached Figure 4 As shown, from Figure 4 It can be seen that the surface of the metal sheet is over-electrolyzed and the electrolysis is uneven. This is because the temperature is high during the electrolysis process, resulting in excessive electrolysis reaction.

[0056] Comparative Example 3

[0057] The treatment method of this comparative example is the same as that of Example 1, except that in step (2), the electrolytic treatment time is 1 hour.

[0058] When other electrolysis conditions remain unchanged, too short an electrolysis treatment time will result in insufficient electrolysis on the surface of the metal sheet, and tool and grinding marks will still remain.

[0059] Comparative Example 4

[0060] The treatment method of this comparative example is the same as that of Example 1, except that in step (2), the voltage of the electrolysis treatment is 10V, and the current of the electrolysis treatment is 150-180V.

[0061] When other conditions of electrolysis remain unchanged, if the voltage and current are too small during electrolysis treatment, it will lead to insufficient electrolysis on the surface of the metal sheet, and the knife marks and grinding marks will still exist.

[0062] Comparative Example 5

[0063] In this comparative example, after the surface of the GH4169 alloy slab was processed by a milling machine, it was washed with clean water to remove stains such as dust and oil on the surface of the metal slab.

[0064] Comparative Example 6

[0065] The processing method of this comparative example is the same as that of comparative example 5, except that: after the milling machine processing, the surface of the metal sheet blank is mechanically polished with an angle grinder, and then cleaned with clean water to remove dust, oil and other stains on the surface of the metal sheet blank.

[0066] Comparative Example 7

[0067] The processing method of this comparative example is the same as that of comparative example 6, except that: after mechanical grinding, the surface is mechanically polished with a polishing cloth and a polishing paste, and then cleaned with clean water to remove dust, oil stains and other stains on the surface of the metal sheet blank.

[0068] Comparative Example 8

[0069] The treatment method of this comparative example is the same as that of comparative example 7, except that: after mechanical polishing, a hydrochloric acid and hydrogen peroxide solution (the volume ratio of hydrochloric acid and hydrogen peroxide is 1:1) is used to chemically corrode the surface of the metal sheet blank, and after the chemical corrosion treatment at room temperature for 15 seconds, it is washed with clean water to remove dust, oil stains and other stains on the surface of the metal sheet blank.

[0070] Performance Testing

[0071] (1) The four-layer construction specimens treated in Example 1 and the control group (specimens without construction interfaces but subjected to the same thermal processing history) were subjected to room temperature and high temperature tensile property tests. In order to make the results more accurate, two sets of data were tested at the same temperature. The test results are shown in Table 1.

[0072] Table 1

[0073]

[0074] It can be seen from the data in Table 1 that the pattern treated with Example 1 exhibits strong performance stability, and the tensile strength, yield strength, elongation and cross-sectional shrinkage rate all reach the level of the control group, and some performances are even slightly higher than those of the control group. The construction pattern obtained after the surface treatment of the embodiment has been restored to a level consistent with the substrate.

[0075] (2) The four-layer construction specimens treated in Example 1 and the control group (specimens without construction interfaces) were subjected to a durability test (after a durability time of more than 48 h, a force of 35 MPa was applied every 10 h until the specimen broke). In order to make the results more accurate, two sets of data were tested at the same temperature. The test results are shown in Table 2.

[0076] Table 2

[0077]

[0078] It can be seen from the data in Table 2 that the pattern treated by Example 1 also exhibits a slightly higher durability than the control group, indicating that the constructed pattern obtained by the surface treatment of the example does not reduce the durability of the pattern.

[0079] (3) The four-layer construction samples treated by Comparative Examples 5 to 8 were subjected to room temperature and high temperature tensile property tests. The test results are shown in Table 3.

[0080] Table 3

[0081] Temperature / ℃ <![CDATA[R p0.2 / MPa]]> <![CDATA[R m / MPa]]> A / ％ Z / ％ Remark Comparative Example 5 Room temperature 1129 1204 6 14 Comparative Example 6 Room temperature 1069 1123 0.5 / Comparative Example 7 Room temperature / 1046 / / Brittle fracture Comparative Example 8 Room temperature 1013 1162 12 21 Comparative Example 5 650 811 871 8 15 Comparative Example 6 650 808 892 2.5 2 Comparative Example 7 650 825 830 2.5 10 Comparative Example 8 650 797 884 7.5 28

[0082] (5) The four-layer construction samples treated by Comparative Examples 5 to 8 were subjected to a durability test (after a durability time of more than 48 hours, a force of 35 MPa was applied every 10 hours until the sample broke). The test results are shown in Table 4.

[0083] Table 4

[0084] serial number Temperature / ℃ Initial stress / MPa Duration time / h Comparative Example 5 650 690 20.50 Comparative Example 6 650 690 48.57 Comparative Example 7 650 690 1.35 Comparative Example 8 650 690 29.15

[0085] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0086] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A homogenized high-temperature alloy billet forming method, characterized in that: The method comprises metal surface treatment, wherein the metal surface treatment comprises the following steps: (1) After surface pretreatment, the metal sheet blank is connected to the positive electrode of the power supply, and the conductor plate is connected to the negative electrode of the power supply; (2) immersing the metal sheet blank and the conductor plate described in step (1) in an acidic electrolyte for electrolytic treatment; the voltage of the electrolytic treatment is 20 to 30 V, the current of the electrolytic treatment is 200 to 350 A, the temperature of the electrolyte during the electrolytic treatment is 20 to 30° C., and the electrolytic treatment time is 1.5 to 2.5 h; (3) After the electrolytic treatment in step (2) is completed, the surface of the metal sheet is pickled.

2. The homogenized high-temperature alloy billet forming method according to claim 1, characterized in that: In the step (1), the surface pretreatment includes first milling or mechanically grinding the surface of the metal sheet blank, and then cleaning the surface of the metal sheet blank with a cleaning liquid; the cleaning liquid includes at least one of water or alcohol.

3. The homogenized high-temperature alloy billet forming method according to claim 1, characterized in that: In the step (1), the conductor plate includes at least one of a lead plate, a platinum plate or a copper plate.

4. The homogenized high-temperature alloy billet forming method according to claim 1, characterized in that: In the step (2), the acidic electrolyte includes at least one of hydrofluoric acid, phosphoric acid, boric acid, sulfuric acid, hydrochloric acid or perchloric acid.

5. The homogenized high-temperature alloy billet forming method according to claim 1 or 4, characterized in that: In the step (2), the conductor plate is placed directly in front of the surface to be processed of the metal sheet blank, and the projection of the conductor plate on the surface to be processed completely covers the surface to be processed.

6. The homogenized high-temperature alloy billet forming method according to claim 5, characterized in that: In the step (2), a distance of 15 to 20 cm is maintained between the conductor plate and the metal sheet blank.

7. The homogenized high-temperature alloy billet forming method according to claim 1, characterized in that: The step (3) also includes performing a first cleaning treatment before the pickling treatment, and performing a second cleaning treatment and a drying treatment after the pickling treatment.

8. The homogenized high-temperature alloy billet forming method according to claim 7, characterized in that: The cleaning liquid used in the first cleaning process and / or the second cleaning process includes at least one of water or alcohol.

9. The homogenized high-temperature alloy billet forming method according to claim 1 or 7, characterized in that: A brush is used for cleaning during the pickling process, and the pickling time is between 30 and 60 seconds.

10. The homogenized high-temperature alloy billet forming method according to claim 1 or 7, characterized in that: The pickling solution used in the pickling treatment includes at least one of hydrochloric acid, sulfuric acid or hydrofluoric acid.

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