阅读说明：本技术 紧固件用gh6159合金锭及其制备方法 (GH6159 alloy ingot for fastener and preparation method thereof ) 是由 张欢欢 栾吉哲 李爱民 田水仙 闫森 耿长建 于 2021-08-25 设计创作，主要内容包括：本发明提供了一种紧固件用GH6159合金锭及其制备方法,该制备方法包括如下步骤：原料经真空感应熔炼后浇注形成电极,然后对电极进行表面处理、真空自耗,得紧固件用GH6159合金锭；原料分别在真空感应熔炼的熔化期和精炼期加入,熔化期原料的加入顺序依次为Ni、Cr、Co、Mo、Fe、碳粉；真空自耗的熔速为2.2-2.8kg/min。本发明提供的紧固件用GH6159合金锭的制备方法,通过采用真空感应熔炼与真空自耗相结合,并限定熔化期特定的原料加入顺序,结合整个真空自耗过程熔速的限定,各步骤参数之间相互配合,能够确保直径大于Φ180mm的合金锭中心及边缘成分、组织及性能的均匀性,提高成材率。(The invention provides a GH6159 alloy ingot for a fastener and a preparation method thereof, wherein the preparation method comprises the following steps: the method comprises the following steps of pouring raw materials after vacuum induction melting to form an electrode, and then carrying out surface treatment and vacuum self-consumption on the electrode to obtain a GH6159 alloy ingot for a fastener; the raw materials are respectively added in the melting period and the refining period of vacuum induction melting, and the adding sequence of the raw materials in the melting period sequentially comprises Ni, Cr, Co, Mo, Fe and carbon powder; the melting rate of vacuum self-consumption is 2.2-2.8 kg/min. According to the preparation method of the GH6159 alloy ingot for the fastener, provided by the invention, the combination of vacuum induction melting and vacuum consumable electrode is adopted, the specific raw material adding sequence in the melting period is limited, the limitation of the melting speed in the whole vacuum consumable electrode process is combined, and the parameters of all the steps are matched with each other, so that the uniformity of components, tissues and performances of the center and the edge of the alloy ingot with the diameter larger than phi 180mm can be ensured, and the yield is improved.)

1. A preparation method of a GH6159 alloy ingot for a fastener is characterized by comprising the following steps:

pouring the raw materials after vacuum induction melting to form an electrode, and then carrying out surface treatment and vacuum self-consumption on the electrode to obtain a GH6159 alloy ingot for the fastener;

the raw materials are added in the melting period and the refining period of the vacuum induction melting respectively, and the raw materials in the melting period sequentially comprise Ni, Cr, Co, Mo, Fe and carbon powder;

the melting speed of the vacuum self-consumption is 2.2-2.8 kg/min.

2. The method for preparing the GH6159 alloy ingot for fasteners as claimed in claim 1, wherein the raw materials added during the refining period are Al, Ti, Nb and ferroboron.

3. The preparation method of the GH6159 alloy ingot for the fastener as claimed in claim 1, wherein the temperature in the melting period is 1460-1500 ℃ and the vacuum degree is less than 30 pa.

4. The preparation method of the GH6159 alloy ingot for the fastener as claimed in claim 1, wherein the temperature in the refining period is 1500-.

5. The preparation method of the GH6159 alloy ingot for fasteners as claimed in claim 1, wherein the refining period is every 15-25min, stirring is carried out for 3-5 min.

6. The preparation method of the GH6159 alloy ingot for fasteners as claimed in any one of claims 1 to 5, wherein the temperature of the pouring is 1460-1470 ℃.

7. The GH6159 alloy ingot for fasteners prepared by the method of any one of claims 1 to 6.

8. The GH6159 alloy ingot for fasteners as claimed in claim 7, which comprises the following components in percentage by mass: less than or equal to 0.04 percent of C, 34.00 to 38.00 percent of Co, 18.00 to 20.00 percent of Cr, 6.00 to 8.00 percent of Mo, 0.25 to 0.75 percent of Nb, 0.10 to 0.30 percent of Al, 2.50 to 3.25 percent of Ti, 8.00 to 10.00 percent of Fe, less than or equal to 0.03 percent of B, less than or equal to 0.20 percent of Mn, less than or equal to 0.20 percent of Si, less than or equal to 0.01 percent of S, less than or equal to 0.02 percent of P, less than or equal to 10ppm of O, less than or equal to 20ppm of N, and the balance of Ni.

Technical Field

The invention relates to the field of high-temperature alloy material processing, in particular to a GH6159 alloy ingot for a fastener and a preparation method thereof.

Background

The high-temperature alloy fastener is an important bearing connecting piece of military and civil aircraft engines, and is mainly used for connecting parts such as rotor interstage parts, rotor and transmission systems, casing interstage parts and the like of the aircraft engines. The fastener is 100 kinds such as high-strength bolt and screw, self-locking nut, stud and swivel nut. The GH6159 alloy is a deformed high-temperature alloy material for a high-strength cobalt-based fastener, and after aging treatment, the cold-drawn alloy has the room-temperature tensile strength of more than 1900MPa, is the highest fastener material in the current 600 ℃ environment, and is also the only material selected for a 600 ℃ high-strength bolt.

With the continuous development of aviation and aerospace technologies, the requirements on the service temperature, the bearing capacity and other properties of the high-temperature alloy material for the fasteners are gradually increased. However, the existing preparation method of the GH6159 alloy is only suitable for alloy ingots with the diameter not more than phi 180mm, and for alloy ingots with the larger bearing capacity and the diameter larger than phi 180mm, the distribution of the center and the edge is uneven and segregation is easy to generate, so that the yield of the alloy ingots with the diameter larger than phi 180mm is reduced. Therefore, a preparation method capable of obtaining a GH6159 alloy ingot for a fastener with high yield, uniform structure and higher bearing capacity is needed.

Disclosure of Invention

Aiming at the defect of low yield when the existing preparation method of the GH6159 alloy for the fastener is used for smelting an alloy ingot with the diameter larger than phi 180mm, the invention provides a preparation method of the GH6159 alloy ingot for the fastener, which has the diameter larger than phi 180mm and high yield.

In order to achieve the purpose of the invention, the embodiment of the invention adopts the following technical scheme:

a preparation method of a GH6159 alloy ingot for a fastener comprises the following steps:

pouring the raw materials after vacuum induction melting to form an electrode, and then carrying out surface treatment and vacuum self-consumption on the electrode to obtain a GH6159 alloy ingot for the fastener;

the raw materials are added in the melting period and the refining period of the vacuum induction melting respectively, and the raw materials in the melting period sequentially comprise Ni, Cr, Co, Mo, Fe and carbon powder;

the melting speed of the vacuum self-consumption is 2.2-2.8 kg/min.

Compared with the prior art, in the preparation method of the GH6159 alloy ingot for the fastener, the formation of carbides and the shape distribution of microstructures can be effectively controlled by controlling the addition of raw materials in a melting period and a refining period respectively and limiting the types of the raw materials added in the melting period and the specific feeding sequence of Ni, Cr, Co, Mo, Fe and carbon powder. By adding the raw materials such as Nb, Al, Ti and the like in the refining period, the range and the distribution uniformity of the raw materials such as Nb, Al, Ti and the like in the alloy ingot can be effectively controlled, and the burning loss of the raw materials such as Nb, Al, Ti and the like can be prevented. By limiting the melting rate of the whole vacuum consumable, the gas impurity elements can be effectively removed, and the segregation of each element and carbide and the burning loss of Nb, Al, Ti and other elements can be prevented. According to the preparation method of the GH6159 alloy ingot for the fastener, vacuum induction melting and vacuum consumable melting are combined, a specific raw material adding sequence in a melting period is limited, the melting speed in the whole vacuum consumable melting process is limited, parameters of all the steps are matched with each other, and the uniformity of components, structures and performances of the center and the edge of the alloy ingot with the diameter larger than phi 180mm can be ensured. Compared with the alloy ingot with the diameter larger than phi 180mm prepared by the existing preparation method of the GH6159 alloy ingot for the fastener, the yield of the alloy ingot with the diameter larger than phi 180mm prepared by the preparation method provided by the invention reaches more than 80%, and is improved by more than 15%.

Optionally, the surface treatment includes buffing, polishing, or the like.

Optionally, the raw materials added in the refining period are Al, Ti, Nb and ferroboron.

Optionally, the temperature of the melting period is 1460-1500 ℃, and the vacuum degree is less than 30 pa.

Optionally, the temperature in the refining period is 1500-.

And stirring for 3-5min every 15-25min in the refining period. The temperature and the vacuum degree in the refining period and the melting period are limited, and the stirring operation in the refining period is combined, so that the content of gas impurities in the alloy ingot can be obviously reduced, and the yield of the alloy ingot with the diameter larger than phi 180mm is further improved.

Preferably, the refining period is not less than 60min, including stirring time.

Optionally, the temperature of the casting is 1460-.

The invention also provides a GH6159 alloy ingot for a fastener, which is prepared by the preparation method of the GH6159 alloy ingot for the fastener.

Optionally, the GH6159 alloy ingot for the fastener consists of the following components in percentage by mass: less than or equal to 0.04 percent of C, 34.00 to 38.00 percent of Co, 18.00 to 20.00 percent of Cr, 6.00 to 8.00 percent of Mo, 0.25 to 0.75 percent of Nb, 0.10 to 0.30 percent of Al, 2.50 to 3.25 percent of Ti, 8.00 to 10.00 percent of Fe, less than or equal to 0.03 percent of B, less than or equal to 0.20 percent of Mn, less than or equal to 0.20 percent of Si, less than or equal to 0.01 percent of S, less than or equal to 0.02 percent of P, less than or equal to 10ppm of O, less than or equal to 20ppm of N, and the balance of Ni.

Drawings

FIG. 1 is an electron microscope scanning image of a cross section of a GH6159 alloy ingot for a fastener, prepared in example 1 of the present invention;

FIG. 2 is an electron microscope scanning image of a cross section of a GH6159 alloy ingot for a fastener prepared in comparative example 1 of the present invention;

FIG. 3 is an electron microscope scan of a cross section of a GH6159 alloy ingot for a fastener prepared according to comparative example 2 of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The composition range of the GH6159 alloy for fasteners is required to be as follows: the composite material comprises the following components in percentage by mass: less than or equal to 0.04 percent of C, 34.00 to 38.00 percent of Co, 18.00 to 20.00 percent of Cr, 6.00 to 8.00 percent of Mo, 0.25 to 0.75 percent of Nb, 0.10 to 0.30 percent of Al, 2.50 to 3.25 percent of Ti, 8.00 to 10.00 percent of Fe, less than or equal to 0.03 percent of B, less than or equal to 0.20 percent of Mn, less than or equal to 0.20 percent of Si, less than or equal to 0.01 percent of S, less than or equal to 0.02 percent of P, less than or equal to 10ppm of O, less than or equal to 20ppm of N, and the balance of Ni.

For comparison, the following examples and comparative examples were prepared according to the following ratio: according to weight percentage, 0.015 percent of C, 7.00 percent of Mo, 0.40 percent of Nb, 2.80 percent of Ti, 0.15 percent of Al, 19.00 percent of Cr, 36.00 percent of Co, 9.00 percent of Fe, 0.012 percent of B and the balance of Ni.

The raw materials adopted in the burdening process are pure metal Ni, pure metal Cr, pure metal Co, pure metal Mo, pure metal Fe, carbon powder, pure metal Al, pure metal Ti, pure metal Nb and ferroboron. The ferroboron alloy comprises the following components in percentage by mass: 0.26% of C, 0.28% of Si, 0.001% of S, 0.03% of P, 81.529% of Fe and 17.68% of B.

Example 1

The embodiment provides a preparation method of a GH6159 alloy ingot for a fastener, which comprises the following steps:

(1) vacuum induction melting: the materials are prepared according to the mixture ratio (the adding amount of each raw material is calculated).

Melting period: sequentially putting Ni, Cr, Co, Mo, Fe and carbon powder into a vacuum induction furnace, and melting at 1470 ℃ and under the vacuum degree of less than 30 pa;

and (3) refining period: after the raw materials added in the melting period are all melted, reducing the vacuum degree to be less than 1Pa, adding Al, Ti, Nb and ferroboron alloy when the temperature is raised to 1500-1510 ℃, and then refining under the condition, wherein the stirring is carried out for 3min every 20min for 60min (including the stirring time);

alloying: and sampling and analyzing after the refining period is finished, and simultaneously supplementing raw materials according to the component range requirement of the GH6159 alloy for the fastener and the analysis result, and adjusting components to ensure that the result of each chemical element is in the required range.

(2) Pouring: pouring the molten steel prepared in the step (1) into a phi 250mm electrode at 1460-1470 ℃, wherein the whole process of the pouring process is protected by argon, and the argon filling: 3000 Pa;

(3) vehicle polishing and vacuum self-consumption: polishing the electrode until no wrinkles, inclusions and the like exist on the surface of the electrode blank, then performing vacuum self-consumption on the polished electrode, and controlling the melting speed in the whole vacuum self-consumption process to be 2.2-2.8kg/min to obtain a GH6159 alloy ingot for fasteners with the diameter of phi 305 mm.

Example 2

The embodiment provides a preparation method of a GH6159 alloy ingot for a fastener, which comprises the following steps:

(1) vacuum induction melting: proportioning according to the proportion (calculating the adding amount of each raw material);

melting period: sequentially putting Ni, Cr, Co, Mo, Fe and carbon powder into a vacuum induction furnace, and melting at 1490 ℃ under the vacuum degree of less than 30pa and 1480-;

and (3) refining period: after the raw materials added in the melting period are all melted, reducing the vacuum degree to be less than 1Pa, adding Al, Ti, Nb and ferroboron alloy when the temperature is raised to 1510-1520 ℃, and then refining under the condition, wherein the stirring is carried out for 5min every 15min for 100min (including the stirring time);

alloying: and sampling and analyzing after the refining period is finished, and simultaneously supplementing raw materials according to the component range requirement of the GH6159 alloy for the fastener and the analysis result, and adjusting components to ensure that the result of each chemical element is in the required range.

(2) Pouring: pouring the molten steel prepared in the step (1) into a phi 250mm electrode at 1460-1470 ℃, wherein the whole process of the pouring process is protected by argon, and the argon filling: 3000 Pa;

(3) vehicle polishing and vacuum self-consumption: polishing the electrode until no wrinkles, inclusions and the like exist on the surface of the electrode blank, then performing vacuum self-consumption on the polished electrode, and controlling the melting speed in the whole vacuum self-consumption process to be 2.2-2.8kg/min to obtain a GH6159 alloy ingot for fasteners with the diameter of phi 305 mm.

Example 3

The embodiment provides a preparation method of a GH6159 alloy ingot for a fastener, which comprises the following steps:

(1) vacuum induction melting: proportioning according to the proportion (calculating the adding amount of each raw material);

melting period: sequentially putting Ni, Cr, Co, Mo, Fe and carbon powder into a vacuum induction furnace, and melting at the temperature of 1490-1500 ℃ under the vacuum degree of less than 30 pa;

and (3) refining period: after the raw materials added in the melting period are all melted, reducing the vacuum degree to be less than 1Pa, adding Al, Ti, Nb and ferroboron alloy when the temperature is raised to 1510-1520 ℃, and then refining under the condition, wherein the stirring is carried out for 4min every 25min for total refining of 80min (including the stirring time);

alloying: and sampling and analyzing after the refining period is finished, and simultaneously supplementing raw materials according to the component range requirement of the GH6159 alloy for the fastener and the analysis result, and adjusting components to ensure that the result of each chemical element is in the required range.

(2) Pouring: pouring the molten steel prepared in the step (1) into a phi 250mm electrode at 1460-1470 ℃, wherein the whole process of the pouring process is protected by argon, and the argon filling: 3000 Pa;

(3) vehicle polishing and vacuum self-consumption: polishing the electrode until no wrinkles, inclusions and the like exist on the surface of the electrode blank, then performing vacuum self-consumption on the polished electrode, and controlling the melting speed in the whole vacuum self-consumption process to be 2.2-2.8kg/min to obtain a GH6159 alloy ingot for fasteners with the diameter of phi 305 mm.

Comparative example 1

The preparation method of the GH6159 alloy ingot for the fastener provided by the comparative example is similar to that of example 1, the difference is only that the adding sequence of raw materials in the melting period is different, and the adding sequence in the melting period in the comparative example is as follows: ni, Mo, Fe, Cr, Co and carbon powder.

Comparative example 2

The preparation method of the GH6159 alloy ingot for the fastener provided by the comparative example is similar to that of the GH6159 alloy ingot for the fastener provided by the example 1, the difference is only that the melting speed in the whole vacuum consumable-up process is different, and the melting speed in the whole vacuum consumable-up process in the comparative example is controlled to be 3.0-3.5 kg/min.

Experimental example 1

The GH6159 alloy ingots for fasteners prepared in the examples and the comparative examples are subjected to component detection (a spectrometer and a carbon-sulfur analyzer), and the content of each element of the GH6159 alloy ingots for fasteners prepared in the examples and the comparative examples is within the range requirement, wherein the content of O, N impurities is shown in the following table.

TABLE 1O, N measurement results of impurity content

Elements and the content wt%	Example 1	Example 2	Example 3	Comparative example 1	Comparative example 2
						O	0.0008	0.0007	0.0008	0.0015	0.0017
N	0.0018	0.0015	0.0018	0.0022	0.0025

From the data in the table, the GH6159 alloy ingot for fasteners with phi 305mm prepared by the preparation method of the GH6159 alloy ingot for fasteners has O content controlled within 10ppm and N content controlled within 20 ppm.

Experimental example 2

Scanning Electron Microscope (SEM) tests are respectively carried out on the cross sections of GH6159 alloy ingots with phi 305mm prepared in example 1 and comparative examples 1-2, and scanning images of the SEM are shown in figures 1-3.

The GH6159 alloy ingot with the diameter of 305mm used for the fastener prepared in each embodiment and comparative example is forged and cogging to the diameter of 150mm under the conditions that the initial forging temperature is 1150 ℃, the final forging temperature is 1100 ℃, the cogging and upsetting rate is 80mm/s and the forging ratio is 4.0; then rolling and cogging to phi 16mm under the conditions that the initial rolling temperature is 1250 ℃, the final rolling temperature is 1000 ℃, the reduction of each pass of the first 2 passes is 40mm, and the reduction of each pass of the later passes is 50mm, peeling to phi 14.7mm after water-cooling solution treatment at 1040 ℃ for 4h, and cold-drawing to obtain the phi 10.5mm bar. The bar with the diameter of 10.5mm obtained by the same treatment method is tested for mechanical properties at room temperature (25 ℃) and 595 ℃, each test item is tested for four times, and the specific test results are shown in the following table 2.

The detection method comprises the following steps:

GB/T2039 metal tensile creep and endurance test method

GB/T4338 metal material high-temperature tensile test method

GB/T6394 metal average grain size determination method

GB/T14999.2 high-temperature alloy microstructure acid leaching test method

GB/T228 metal material room temperature tensile test method

Rockwell hardness test of GB/T230.1 metal material.

TABLE 2 results of mechanical Properties measurements

As can be seen from the data in the above table and the attached figures 1-3, the GH6159 alloy ingot for fasteners with the diameter of phi 305mm, which is prepared by the preparation method of the GH6159 alloy ingot for fasteners, provided by the invention, has the advantages that the formation of carbides and the morphological distribution of microstructures can be effectively controlled by combining the combination of vacuum induction melting and vacuum self-consumption, limiting the specific raw material adding sequence in the melting period and combining the limitation of the melting speed in the whole vacuum self-consumption process, and the parameters of all the steps are matched with each other, so that the uniformity of the center and edge components, the structure and the performance of the alloy ingot with the diameter of phi 180mm is ensured, the high-power structure is uniform, and the mechanical property of the product is improved.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents or improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.