CN117701926A - A method for preparing large-size ingots of easily segregated nickel-based alloys - Google Patents

Abstract

This application relates to the technical field of nickel-based alloy smelting, and specifically discloses a method for preparing large-size ingots of nickel-based alloys that are prone to segregation. The preparation method specifically includes the following steps: vacuum induction smelting → electrode annealing → electroslag remelting smelting → electroslag ingot annealing → forging electrodes → vacuum consumable smelting; the electrode annealing includes first-stage annealing and second-stage annealing; In the first-stage annealing treatment, the annealing temperature is 400-600°C, and the holding time is 2-4h; in the second-stage annealing treatment, the annealing temperature is 800-1000°C, and the holding time is 6-8h; The temperature rise rate from the first stage annealing treatment to the second stage annealing treatment does not exceed 70°C/h. The preparation method provided in this application is suitable for GH4065A and such high-temperature alloys close to the grade. The produced ingots are φ610mm and have a unit weight of more than 4t. The metallurgical quality is better than the consumable ingots produced by Sanlian Smelting.

Description

A method for preparing large-size ingots of easily segregated nickel-based alloys

Technical field

The present application relates to the technical field of nickel-based alloy smelting, and more specifically, to a method for preparing large-size ingots of nickel-based alloys that are prone to segregation.

Background technique

With the continuous development of aero-engine technology, the hot-end components of aero-engines have increasingly higher requirements on the temperature they can withstand. This requires high-temperature alloy materials with higher temperature-bearing capacity to meet the use requirements of hot-end components of aeroengines. In particular, the demand for high-performance high-temperature alloy materials for manufacturing turbine disks is more urgent.

In recent years, my country has successively developed turbine disc materials represented by alloys such as GH4065A and GH4720Li. Such materials precipitate a higher content of γ' phase by adding a large amount of Al and Ti content (Al+Ti>5.5wt%). After strengthening, the maximum service temperature of the alloy exceeds 700°C, which better meets the requirements for the use of turbine disks in high-thrust engines. Among them, GH4065A alloy adopts the "cast-forging" production method. The performance of the turbine disk forgings produced reaches the level of the second-generation powder disk, and the production cost is greatly reduced. While meeting the performance requirements of the turbine disk forgings, it is extremely economical and extremely The earth meets the needs of civil aviation engines.

At present, GH4065A alloy is produced by triple smelting, namely vacuum induction + electroslag remelting + vacuum self-consumption. First, through vacuum induction and electroslag remelting, dense consumable electrodes are obtained while greatly reducing the content of S and other impurity elements in the alloy to purify the alloy. The consumable electrode forms a consumable ingot after vacuum consumable remelting, which is further degassed and forms a dendritic solidification structure in the water-cooled crystallizer, which is more conducive to subsequent thermal processing.

The conventional ingot type of consumable ingots produced by Sanlian Smelting in China is The weight of the ingot is about 2t. After the steel ingot is hot-processed and forged, the weight of the finished bar is only about 1t. However, as the requirements for the size of turbine disks in aero-engines continue to increase, especially the turbine disks used in larger thrust engines for wide-body passenger aircraft, the size and unit weight of the turbine disks are required to be larger. The consumable ingots produced by conventional Sanlian smelting are of small size and weight. Therefore, conventional ingot materials cannot meet the requirements and the material utilization rate is also very low.

Among related technologies, there is no reference technology for the preparation method of large-size ingots of alloys prone to segregation. Therefore, there is an urgent need to develop key technologies for large-size ingots of alloys that are prone to segregation to meet the requirements for high-temperature alloy materials for hot-end components of aerospace engines.

Contents of the invention

This application provides a method for preparing large-size ingots of nickel-based alloys that are prone to segregation. The large-size ingots of nickel-based alloys prepared by this preparation method can meet the production requirements for high-performance nickel-based alloy large-size forgings required by aerospace engines, gas turbines, etc. Require.

The method for preparing large-size ingots of easily segregated nickel-based alloys provided in this application is suitable for GH4065A and such high-temperature alloys close to the grade. The ingots produced The unit weight is more than 4t, and the metallurgical quality is better than the consumable ingots produced by Sanlian Smelting. The breakthrough in technology for preparing large-size high-temperature alloy ingots provided by this application meets the requirements for the use of high-performance nickel-based alloys in aerospace engines, gas turbines, etc., and at the same time greatly improves the material utilization rate from finished bars to forgings.

In the first aspect, this application provides a method for preparing large-size ingots of nickel-based alloys that are prone to segregation, using the following technical solution:

A method for preparing large-size ingots of easily segregated nickel-based alloys, characterized in that the preparation method specifically includes the following steps: vacuum induction smelting → electrode annealing → electroslag remelting smelting → electroslag ingot annealing → forging electrodes → vacuum Self-consumption smelting;

The electrode annealing includes first-stage annealing and second-stage annealing;

In the first stage of annealing treatment, the annealing temperature is 400-600°C, and the holding time is 2-4 hours;

In the second stage annealing treatment, the annealing temperature is 800-1000°C, and the holding time is 6-8 hours;

The temperature rise rate from the first stage annealing treatment to the second stage annealing treatment does not exceed 70°C/h.

Preferably, in the first stage of electrode annealing, the annealing temperature is 500-550°C.

Preferably, in the second stage of electrode annealing, the annealing temperature is 850-930°C.

In a specific embodiment, in the first stage of electrode annealing, the annealing temperature may be 400°C, 500°C, 550°C, or 600°C.

In some specific embodiments, in the first stage of electrode annealing, the annealing temperature may be 400-500°C, 400-550°C, 400-600°C, 500-550°C, or 550-600°C.

In a specific embodiment, in the first stage annealing treatment of the electrode annealing, the holding time may be 2h, 3h, or 4h.

In some specific embodiments, in the first stage annealing treatment of the electrode annealing, the holding time may be 2-3h, 3-4h, or 2-4h.

In a specific embodiment, in the second stage annealing treatment of the electrode annealing, the annealing temperature may be 800°C, 850°C, 900°C, 930°C, or 1000°C.

In some specific embodiments, in the second stage annealing treatment of electrode annealing, the annealing temperature can be 800-850°C, 800-900°C, 800-930°C, 800-1000°C, 850-900°C, 850°C -930℃, 850-1000℃, 900-930℃, 900-1000℃, 930-1000℃.

In a specific embodiment, in the second stage annealing treatment of the electrode annealing, the holding time may be 6h, 7h, or 8h.

In some specific embodiments, in the second stage annealing treatment of the electrode annealing, the holding time may be 6-7h, 6-8h, or 7-8h.

In a specific embodiment, in the electrode annealing step, the temperature rise rate from the first stage annealing treatment to the second stage annealing treatment may be 50°C/h, 55°C/h, or 65°C/h.

In some specific embodiments, in the electrode annealing step, the temperature rise rate from the first stage annealing treatment to the second stage annealing treatment may be 50-55°C/h, 50-65°C/h, 55 -65℃/h.

Preferably, the electroslag ingot annealing includes first-stage annealing and second-stage annealing;

In the first stage of annealing treatment, the annealing temperature is 300-500°C, and the holding time is 4-6 hours;

In the second stage annealing treatment, the annealing temperature is 800-1000°C, and the holding time is 10-15h;

The temperature rise rate from the first stage annealing treatment to the second stage annealing treatment does not exceed 70°C/h.

Preferably, in the first stage of annealing treatment of electroslag ingot annealing, the annealing temperature is 350-450°C.

Preferably, in the second stage annealing treatment of electroslag ingot annealing, the annealing temperature is 850-950°C.

In a specific embodiment, in the first stage of annealing treatment of electroslag ingot annealing, the annealing temperature may be 300°C, 350°C, 450°C, or 500°C.

In some specific embodiments, in the first stage of annealing treatment of electroslag ingot annealing, the annealing temperature can be 300-350°C, 300-450°C, 300-500°C, 350-450°C, 350-500°C , 450-500℃.

In a specific embodiment, in the first stage of annealing treatment of electroslag ingot annealing, the holding time may be 4h, 5h, or 6h.

In some specific embodiments, in the first stage of annealing treatment of electroslag ingot annealing, the holding time may be 4-5h, 4-6h, or 5-6h.

In a specific embodiment, in the second stage annealing treatment of electroslag ingot annealing, the annealing temperature may be 800°C, 850°C, 900°C, 950°C, or 1000°C.

In some specific embodiments, in the second stage annealing treatment of electroslag ingot annealing, the annealing temperature can be 800-850°C, 800-900°C, 800-950°C, 800-1000°C, 850-900°C , 850-950℃, 850-1000℃, 900-950℃, 900-1000℃, 950-1000℃.

In a specific embodiment, in the second stage annealing process of electroslag ingot annealing, the holding time may be 12h, 13h, or 15h.

In some specific embodiments, in the second stage annealing treatment of electroslag ingot annealing, the holding time may be 12-13h, 12-15h, or 13-15h.

In a specific embodiment, in the electroslag ingot annealing step, the temperature rise rate from the first stage annealing treatment to the second stage annealing treatment may be 50°C/h, 55°C/h, 65°C/h. h.

In some specific embodiments, in the electroslag ingot annealing step, the temperature rise rate from the first stage annealing treatment to the second stage annealing treatment may be 50-55°C/h or 50-65°C/h. ,55-65℃/h.

Preferably, in the electroslag remelting smelting step, the melting rate is 4.0-7.0Kg/min.

In a specific embodiment, in the electroslag remelting smelting step, the melting speed can be 4.0Kg/min, 5.0Kg/min, 5.5Kg/min, 6.5Kg/min, or 7.0Kg/min.

In some specific embodiments, in the electroslag remelting smelting step, the melting rate can be 4.0-5.0Kg/min, 4.0-5.5Kg/min, 4.0-6.5Kg/min, 4.0-7.0Kg/min, 5.0-5.5Kg/min, 5.0-6.5Kg/min, 5.0-7.0Kg/min, 5.5-6.5Kg/min, 5.5-7.0Kg/min, 6.5-7.0Kg/min.

Preferably, in the vacuum consumable smelting step, the melting rate is 2.5-3.5Kg/min.

In a specific embodiment, in the vacuum consumable smelting step, the melting rate can be 2.5Kg/min, 2.7Kg/min, 3.1Kg/min, 3.3Kg/min, or 3.5Kg/min.

In some specific embodiments, in the vacuum consumable smelting step, the melting rate can be 2.5-2.7Kg/min, 2.5-3.1Kg/min, 2.5-3.3Kg/min, 2.5-3.5Kg/min, 2.7 -3.1Kg/min, 2.7-3.3Kg/min, 2.7-3.5Kg/min, 3.1-3.3Kg/min, 3.1-3.5Kg/min, 3.3-3.5Kg/min.

In a second aspect, the present application provides a large-size ingot of a nickel-based alloy that is prone to segregation and is prepared by the above preparation method. The ingot The unit weight is more than 4t, and the metallurgical quality is better than the consumable ingots produced by Sanlian Smelting. The breakthrough in technology for preparing large-size high-temperature alloy ingots provided by this application meets the requirements for the use of high-performance nickel-based alloys in aerospace engines, gas turbines, etc., and at the same time greatly improves the material utilization rate from finished bars to forgings.

To sum up, this application has the following beneficial effects:

The preparation method provided in this application can be used to prepare The ingot shape and unit weight are over 4t, and the metallurgical quality is better than the self-consumable ingots produced by Sanlian Smelting. Through open forging, this steel ingot can be used to prepare bars with a unit weight of more than 2t, reaching the same level as foreign materials, effectively meeting the use requirements of high-temperature alloys for domestic aerospace engines, and at the same time, greatly improving the quality of the high-temperature alloy from bars to forgings. Utilization.

Description of the drawings

Figure 1 is a low-magnification detection result of a rod obtained from the consumable ingot prepared in Example 4.

Detailed ways

The purpose of this application is to provide a method for preparing large-size ingots of nickel-based alloys that are prone to segregation. The preparation method is suitable for GH4065A and similar high-temperature alloys close to the grade. Using this preparation method, ingots can be prepared The unit weight is more than 4t, and the metallurgical quality is better than the consumable ingots produced by Sanlian Smelting.

In this application, GH4065A is only used as an example to illustrate the preparation method provided in this application.

The chemical composition ratio of GH4065A alloy is as follows: in terms of weight percentage, C: 0.005-0.020%; Cr: 15.5-16.5%; Co: 12.5-13.5%; W: 3.8-4.2%; Mo: 3.8-4.2%; Al: 1.90-2.40%; Ti: 3.55-3.90%; Nb: 0.6-0.9%; Zr: 0.03-0.06%; B: 0.012-0.020%; Mg＜0.005%; N: ≤35ppm; S≤10ppm; Fe≤1.2 ;The balance is nickel and unavoidable impurities.

The method for preparing large-size ingots of easily segregated nickel-based alloys provided in this application specifically includes the following steps:

Vacuum induction smelting → electrode annealing → electroslag remelting smelting → electroslag ingot annealing → forged electrode → vacuum consumable smelting.

details as follows:

1. Vacuum induction smelting process: 12t vacuum induction furnace is used for smelting and pouring electrode.

The process mainly includes the following stages:

(1) Add Ni, Cr, Co, W and other main materials, and add C at the same time, perform high vacuum and high-power smelting, and use the C-O reaction for degassing to ensure that the O and H content in the molten steel is reduced to the control requirements;

(2) After the main materials are completely dissolved, add alloying elements such as Al, Ti, Nb, Zr, and B;

(3) Take the finished product sample for composition analysis. After the main element content meets the index requirements, fill with Ar gas, add Mg element, stir for 5 minutes, tap out the steel, and obtain the cast electrode.

2. Electrode annealing: After the cast electrode is completely solidified, the demoulding process is completed immediately; then it is sent to the annealing furnace for annealing to obtain the induction electrode.

First, perform the first stage of treatment at a temperature of 400-600°C and keep warm for 2-4 hours;

Then, carry out the second stage of treatment, with a temperature of 800-1000°C and a holding time of 6-8 hours.

The heating rate from the first stage to the second stage does not exceed 70℃/h. After the holding time is over, the furnace is cooled to room temperature and discharged.

3. Electroslag remelting smelting: Use 10t electroslag remelting furnace to smelt and prepare Electroslag ingot.

The surface of the induction electrode is ground clean, and stains, oxide scales, water stains, etc. are not allowed to exist. The shrinkage hole of the induction electrode head is smelted downward. The melting speed is set at 4.0-7.0Kg/min to obtain the electroslag ingot.

After the remelting is completed, it is hot sent for annealing for 120 minutes. During the waiting process, the surface temperature of the electroslag ingot must not be lower than 300°C to prevent cracks.

4. Electroslag ingot annealing: After the electroslag ingot is completely solidified, the demoulding process is completed immediately, and then sent to the annealing furnace for annealing treatment to obtain the annealed electroslag ingot.

First, carry out the first stage of treatment, with a temperature of 300-500°C and a heat preservation period of 4-6 hours.

Then, carry out the second stage treatment, the temperature is 800-1000℃, and the holding time is 10-15h.

The heating rate from the first stage to the second stage does not exceed 70℃/h. After the holding time is over, the furnace is cooled to room temperature and discharged.

5. Forged electrode: The surface of the annealed electroslag ingot is ground to remove impurities such as residual slag and oxides at the end of the annealed electroslag ingot.

The annealed electroslag ingot is heated to 1150°C and forged to diameter after multiple fires. After forging the electrode, the surface of the forged electrode is ground and the head and tail are cut off.

6. Vacuum consumable smelting: Use 8t vacuum consumable furnace to smelt and prepare Self-consumable tablets.

Smelt the shrinkage hole of the forged electrode head downward, and set the melting speed at 2.5-3.5Kg/min to obtain a consumable ingot.

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without any creative work shall fall within the scope of protection of this application.

Example

Example 1

This embodiment provides a method for preparing large-size ingots of nickel-based alloys that are prone to segregation.

The preparation method specifically includes the following steps:

Vacuum induction smelting → electrode annealing → electroslag remelting smelting → electroslag ingot annealing → forged electrode → vacuum consumable smelting.

details as follows:

1. Vacuum induction smelting process: 12t vacuum induction furnace is used for smelting and pouring electrode.

The process mainly includes the following stages:

(1) Add Ni, Cr, Co, W and other main materials, and add C at the same time, perform high vacuum and high-power smelting, and use the C-O reaction for degassing to ensure that the O and H content in the molten steel is reduced to the control requirements;

(2) After the main materials are completely dissolved, add alloying elements such as Al, Ti, Nb, Zr, and B;

(3) Take the finished product sample for composition analysis. After the main element content meets the index requirements, fill it with Ar gas, add Mg element, stir for 5 minutes, tap out the steel, and obtain the cast electrode.

2. Electrode annealing: After the cast electrode is completely solidified, the demoulding process is completed immediately; then it is sent to the annealing furnace for annealing to obtain the induction electrode.

First, the first stage of treatment is carried out, the temperature is 400°C, and the temperature is kept for 4 hours;

Then, the second stage treatment was carried out, with the temperature being 850°C and the holding time being 8 hours.

The heating rate from the first stage to the second stage is 50℃/h. After the holding time is over, the furnace is cooled to room temperature and discharged.

3. Electroslag remelting smelting: Use 10t electroslag remelting furnace to smelt and prepare Electroslag ingot.

The surface of the induction electrode is ground clean, and stains, oxide scale, water stains, etc. are not allowed to exist. The shrinkage hole of the induction electrode head is smelted downward. The melting speed is set at 4.5Kg/min to obtain the electroslag ingot.

After the remelting is completed, it is hot sent for annealing for 120 minutes. During the waiting process, the surface temperature of the electroslag ingot must not be lower than 300°C to prevent cracks.

4. Electroslag ingot annealing: After the electroslag ingot is completely solidified, the demoulding process is completed immediately, and then sent to the annealing furnace for annealing treatment to obtain the annealed electroslag ingot.

First, the first stage of treatment is carried out, the temperature is 450°C, and the temperature is maintained for 6 hours.

Then, the second stage treatment is carried out, the temperature is 950°C, and the holding time is 12 hours.

The heating rate from the first stage to the second stage is 60°C/h. After the holding time is over, the furnace is cooled to room temperature and discharged.

5. Forged electrode: The surface of the annealed electroslag ingot is ground to remove impurities such as residual slag and oxides at the end of the annealed electroslag ingot.

The annealed electroslag ingot is heated to 1150°C and forged to diameter after multiple fires. After forging the electrode, the surface of the forged electrode is ground and the head and tail are cut off.

6. Vacuum consumable smelting: Use 8t vacuum consumable furnace to smelt and prepare Self-consumable tablets.

Smelt the shrinkage hole of the forged electrode head downward, and set the melting speed at 2.8Kg/min to obtain a consumable ingot.

Example 2-10

Examples 2-10 provide a method for preparing large-size ingots of nickel-based alloys that are prone to segregation.

The difference between the preparation method of the above embodiment and Embodiment 1 lies in the parameter settings of each step, as shown in Table 1.

The difference between Embodiment 2-4 and Embodiment 1 lies in the parameter settings of each step.

The difference between Examples 5-7 and Example 4 lies in the annealing temperature in the first stage of the electrode annealing step.

The difference between Examples 8-9 and Example 4 lies in the holding time in the first stage of the electrode annealing step.

The difference between Example 10 and Example 4 lies in the temperature rise rate from the first stage to the second stage of the electrode annealing step.

Table 1 Parameter settings of each step in Examples 1-16

Examples 11-16

Embodiments 11 to 16 respectively provide a method for preparing large-size ingots of nickel-based alloys that are prone to segregation.

The difference between the preparation method of the above embodiment and Embodiment 4 lies in the parameter settings of each step, as shown in Table 1.

The difference between Examples 11-14 and Example 4 lies in the annealing temperature in the first stage of the electroslag ingot annealing step.

The difference between Examples 15-16 and Example 4 lies in the holding time of the first stage of the electroslag ingot annealing step.

Comparative ratio

Comparative Example 1-6

Comparative Examples 1-6 respectively provide a method for preparing large-size ingots of nickel-based alloys that are prone to segregation.

The difference between the preparation method of the above comparative example and Example 4 lies in the parameter settings of each step, as shown in Table 3.

The difference between Comparative Examples 1-3 and Example 4 lies in the annealing temperature in the first stage of the electrode annealing step.

The difference between Comparative Example 4-5 and Example 4 lies in the holding time in the first stage of the electrode annealing step.

The difference between Comparative Example 6 and Example 4 lies in the temperature rise rate from the first stage to the second stage of the electrode annealing step.

Table 2 Parameter settings for each step of Comparative Examples 1-6

Performance testing test

The consumable ingots prepared in the above-mentioned Examples 1-16 and Comparative Examples 1-6 were subjected to homogenization treatment according to the homogenization process, and then were opened using a forging process.

The homogenization process is as follows: Insulate at 1160-1180℃ for 36-108h, then cool in steps of 20℃, keep each step for 4-10h, cool to below 1100℃ for conventional furnace cooling, and cool the furnace to above 900℃ Can be air cooled out of the oven.

The forging process is as follows: repeated upsetting is performed above and below the alloy's full melting temperature to break the as-cast structure and form a two-phase fine-grained structure.

The heads and tails of the four bars were inspected at low magnification, and the entire bar was inspected for flaw detection. The test results are shown in Table 3.

Table 3 Results evaluation table of rods prepared using consumable ingots

As can be seen from Table 3, the preparation method provided by this application can be used to prepare The ingot shape and unit weight are over 4t, and the metallurgical quality is better than the self-consumable ingots produced by Sanlian Smelting. Through open forging, this steel ingot can be used to prepare bars with a unit weight of more than 2t, reaching the same level as foreign materials, effectively meeting the use requirements of high-temperature alloys for domestic aerospace engines, and at the same time, greatly improving the quality of the high-temperature alloy from bars to forgings. Utilization.

The low-magnification detection results of the rod obtained from the consumable ingot prepared in Example 4 are shown in Figure 1. It can be seen from Figure 1 that the rod obtained by using the consumable ingot prepared in Example 4 of the present application has no metallurgical defects such as "white spots" and "point deviation". It shows that the consumable ingots prepared according to the preparation method provided in this application have good metallurgical quality and can be used in the engineering production of GH4065A and similar high-temperature alloys close to the grade.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or equivalent substitutions are made to some of the technical features; however, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions in the embodiments of the present application.

Claims (10)

1. The preparation method of the large-size ingot casting of the easy segregation nickel-based alloy is characterized by comprising the following steps of:

vacuum induction smelting, electrode annealing, electroslag remelting smelting, electroslag ingot annealing, electrode forging and vacuum consumable smelting;

the electrode annealing includes a first stage annealing and a second stage annealing;

in the first stage annealing treatment, the annealing temperature is 400-600 ℃, and the heat preservation time is 2-4h;

in the second stage annealing treatment, the annealing temperature is 800-1000 ℃ and the heat preservation time is 6-8h;

and the heating rate from the first stage annealing treatment to the second stage annealing treatment is not more than 70 ℃/h.

2. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the first stage annealing treatment of the electrode annealing, the annealing temperature is 500-550 ℃.

3. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the second stage annealing treatment of the electrode annealing, the annealing temperature is 850-930 ℃.

4. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

the electroslag ingot annealing comprises a first-stage annealing and a second-stage annealing;

in the first stage annealing treatment, the annealing temperature is 300-500 ℃, and the heat preservation time is 4-6h;

in the second stage annealing treatment, the annealing temperature is 800-1000 ℃ and the heat preservation time is 10-15h;

and the heating rate from the first stage annealing treatment to the second stage annealing treatment is not more than 70 ℃/h.

5. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the first stage annealing treatment of the electroslag ingot annealing, the annealing temperature is 350-450 ℃.

6. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the second stage annealing treatment of the electroslag ingot annealing, the annealing temperature is 850-950 ℃.

7. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the electroslag remelting smelting step, the smelting speed is 4.0-7.0Kg/min.

8. The method for preparing a large-size ingot of the easy segregation nickel-base alloy according to claim 1, wherein,

in the vacuum consumable smelting step, the smelting speed is 2.5-3.5Kg/min.

9. An easy segregation nickel-base alloy large-size ingot produced by the preparation method of the easy segregation nickel-base alloy large-size ingot of any one of claims 1-8.

10. The large-size ingot of easy segregation nickel-base alloy of claim 9, wherein the easy segregation nickel-base alloy large-size ingot phi 610mm, single weight above 4 t.