阅读说明：本技术 2014铝合金轮毂模锻件的无锆毛坯均热及冷却方法 (Zirconium-free blank soaking and cooling method for 2014 aluminum alloy hub die forging ) 是由 陈丽芳 吴道祥 王正安 林海涛 曾庆华 于 2019-11-28 设计创作，主要内容包括：本发明公开一种2014铝合金轮毂模锻件的无锆毛坯均热及冷却方法,第一级加热：以每小时55±5℃进行升温,至450℃-480℃±5℃后,保温450±5℃时间4.5-5.5小时；第二级加热：以每小时10±5℃进行升温,至505℃-525℃±5℃后,保温505±5℃时间29-35小时；第一级冷却；风冷80-100分钟,风机转向频率为15-30min/次；第二级冷却：同时风冷和雾冷80-100分钟,风机转向频率为15-30min/次,雾冷所用水的水流量为10-20m<Sup>3</Sup>/h；第三级冷却：同时风冷和水冷25-35分钟,水流量为40-70m<Sup>3</Sup>/h。能够极大的提高2014铝合金航空精密轮毂模锻件的产品质量。(The invention discloses a zirconium-free blank soaking and cooling method of a 2014 aluminum alloy hub die forging, which comprises the following steps of: raising the temperature to 450-480 +/-5 ℃ per hour at 55 +/-5 ℃, and then preserving the temperature for 4.5-5.5 hours at 450 +/-5 ℃; second-stage heating: heating to 505-525 +/-5 ℃ at 10 +/-5 ℃ per hour, and then preserving the heat at 505 +/-5 ℃ for 29-35 hours; first-stage cooling; air cooling for 80-100 min, and the fan steering frequency is 15-30 min/time; and (3) second-stage cooling: simultaneously air cooling and fog cooling for 80-100 min, fan rotation frequency of 15-30 min/time, and water flow rate of water for fog cooling of 10-20m 3 H; and (3) third-stage cooling: simultaneously cooling with air and water for 25-35 minutes at water flow rate of 40-70m 3 H is used as the reference value. The product quality of 2014 aluminum alloy aviation precision hub die forging can be greatly improved.)

1. A zirconium-free blank soaking and cooling method of a 2014 aluminum alloy hub die forging is characterized in that the zirconium-free blank comprises 0.65-0.75% of Si, less than or equal to 0.10% of Fe, 4.00-4.40% of Cu, 0.70-0.90% of Mn, 0.45-0.55% of Mg, 0.04-0.07% of Cr, less than or equal to 0.20% of Zn and less than or equal to 0.15% of Ti;

in the first stage heating: raising the temperature to 450-480 +/-5 ℃ per hour at 55 +/-5 ℃, and then preserving the temperature for 4.5-5.5 hours at 450 +/-5 ℃;

during the second stage of heating: continuing the first-stage heating, raising the temperature by 10 +/-5 ℃ per hour to 505-525 +/-5 ℃, and then preserving the temperature at 505 +/-5 ℃ for 29-35 hours;

during the first stage of cooling; continuing the second-stage heating, and air-cooling for 80-100 minutes, wherein the rotation frequency of the fan is 15-30 min/time;

in the second stage of cooling: continuing the first stage cooling, simultaneously cooling with air and fog for 80-100 min, rotating frequency of the fan 15-30 min/time, and water flow rate of water for fog cooling 10-20m³/h；

During the third stage cooling: continuing the second stage cooling, simultaneously cooling with air and water for 25-35 minutes, keeping the fan in non-rotation direction, and controlling water flow at 40-70m³/h。

2. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein during the first stage heating: raising the temperature to 480 +/-5 ℃ per hour at 55 +/-5 ℃, keeping the temperature for 5-6 hours, and then preserving the temperature for 5 hours at 450 +/-5 ℃.

3. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 2, wherein during the first stage heating: to 480 + -5 deg.C and held for 5.5 hours.

4. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein during the second stage heating: heating to 525 + -5 deg.C per hour at 10 + -5 deg.C for 2-3 hr, and holding at 505 + -5 deg.C for 30 hr.

5. The method for soaking and cooling a zirconium-free blank of 2014 aluminum alloy hub die forgings of claim 4, wherein during the second stage heating: to 525 ± 5 ℃ and held for 2.5 hours.

6. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein during the first stage heating: keeping the temperature at 450 +/-5 ℃ for 5 hours.

7. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein during the second stage heating: keeping the temperature at 505 +/-5 ℃ for 30 hours.

8. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein during the second stage heating: keeping the temperature at 505 +/-5 ℃ for 34 hours.

9. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein in the second stage of cooling: simultaneously cooling by air and mist for 90 min, turning frequency of the fan being 20 min/time, and water flow rate of water for mist cooling being 15m³And h, the fan power is 90% of rated power.

10. The method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging according to claim 1, wherein in the third stage of cooling: simultaneously air cooling and water cooling for 30 minutes, and the water flow is 55m³And h, the fan power is 90% of rated power.

Technical Field

The invention relates to the technical field of manufacturing of aviation precision hub die forgings, in particular to a zirconium-free blank soaking and cooling method of a 2014 aluminum alloy hub die forging.

Background

The large airplane is provided with a typical-specification forge piece which is the largest forge piece in the 2014-high aluminum alloy aviation precision hub die forge piece: and die forging of half wheel (inboard). The half-wheel (inboard) die forging is a precision die forging and is a disc die forging, the maximum outer hub size of a part is phi 593.3 multiplied by 309.1mmmm, and the maximum outer contour size of the die forging is phi 616.5 multiplied by 314.2 mm.

The parts inside the half wheel cabin are shown in fig. 1 and fig. 2, and fig. 1 is a first side view structure schematic diagram of the 2014 aluminum alloy aviation precision hub die forging provided by the embodiment of the invention; fig. 2 is a schematic side view of a 2014 aluminum alloy aviation precision hub die forging, which is a relatively complex large aluminum alloy forging, the maximum external dimension of the forging is phi 600mm × 310mm, the maximum depth of the cylinder is 240mm, the minimum position of the cylinder wall is only 7.6mm, and the maximum position of the cylinder wall is 16mm, and the forging is a typical deep-cylinder thin-wall part, the basic body of which is a cylinder 12, the upper part of the cylinder 12 is provided with an annular outward extension part 11, an inner concave part is arranged above the outward extension part 11, 9 lugs 14 arranged in an annular manner are arranged at the junction of the inner concave part and the inner wall of the cylinder 12, and the bottom of the cylinder 12 is provided with 9 annular elliptical pits 13, specifically, the part is thin at the bottom of the cylinder, and has 9 uniformly distributed elliptical pits 13 at the same time, and the shape is complex; the upper side of the part is correspondingly provided with 9 lugs 14, and the lugs 14 are high in height, thin in wall thickness, small in inclination and small in vertical projection area, and belong to parts which are difficult to form and easy to have defects.

The half-wheel (inboard) die forging is a precision die forging, namely a disc die forging, and has the advantages of deep cavity, thin wall, high rib, small fillet, more bosses at the inner cavity and the bottom and more complex cavity. The half-wheel (inboard) die forging has a large number of non-machined surfaces, small machining allowance, high surface quality requirement and extremely high dimensional precision requirement; the die forging has deep cavity, high and thin ribs and difficult precision die forging forming; the 2014 alloy is easy to generate coarse grains, and the uniformity of the structure performance is difficult to control; the safety performance requirement of the wheel hub is high, and the comprehensive performance requirement is extremely high. Therefore, the biggest difficulties of the hub die forging are large difficulty in controlling the size and the uniformity of the structure performance.

Therefore, how to provide a zirconium-free blank soaking and cooling method for 2014 aluminum alloy hub die forging to improve product quality is a technical problem to be solved urgently by technical personnel in the field.

Disclosure of Invention

In view of the above, the present invention aims to provide a method for soaking and cooling a zirconium-free blank of a 2014 aluminum alloy hub die forging to improve the product quality.

In order to achieve the purpose, the invention provides the following technical scheme:

a zirconium-free blank soaking and cooling method of a 2014 aluminum alloy hub die forging comprises 0.65-0.75% of Si, less than or equal to 0.10% of Fe, 4.00-4.40% of Cu, 0.70-0.90% of Mn, 0.45-0.55% of Mg, 0.04-0.07% of Cr, less than or equal to 0.20% of Zn and less than or equal to 0.15% of Ti;

in the first stage heating: raising the temperature to 450-480 +/-5 ℃ per hour at 55 +/-5 ℃, and then preserving the temperature for 4.5-5.5 hours at 450 +/-5 ℃;

during the second stage of heating: continuing the first-stage heating, raising the temperature by 10 +/-5 ℃ per hour to 505-525 +/-5 ℃, and then preserving the temperature at 505 +/-5 ℃ for 29-35 hours;

during the first stage of cooling; continuing the second-stage heating, and air-cooling for 80-100 minutes, wherein the rotation frequency of the fan is 15-30 min/time;

in the second stage of cooling: continuing the first stage cooling, simultaneously cooling with air and fog for 80-100 min, rotating frequency of the fan 15-30 min/time, and water flow rate of water for fog cooling 10-20m³/h；

During the third stage cooling: continuing the second stage cooling, simultaneously cooling with air and water for 25-35 minutes, keeping the fan in non-rotation direction, and controlling water flow at 40-70m³/h。

Preferably, in the first stage heating: raising the temperature to 480 +/-5 ℃ per hour at 55 +/-5 ℃, keeping the temperature for 5-6 hours, and then preserving the temperature for 5 hours at 450 +/-5 ℃.

Preferably, in the first stage heating: to 480 + -5 deg.C and held for 5.5 hours.

Preferably, in the second stage heating: heating to 525 + -5 deg.C per hour at 10 + -5 deg.C for 2-3 hr, and holding at 505 + -5 deg.C for 30 hr.

Preferably, in the second stage heating: to 525 ± 5 ℃ and held for 2.5 hours.

Preferably, in the first stage heating: keeping the temperature at 450 +/-5 ℃ for 5 hours.

Preferably, in the second stage heating: keeping the temperature at 505 +/-5 ℃ for 30 hours.

Preferably, in the second stage heating: keeping the temperature at 505 +/-5 ℃ for 34 hours.

Preferably, in the second stage cooling: simultaneously cooling by air and mist for 90 min, turning frequency of the fan being 20 min/time, and water flow rate of water for mist cooling being 15m³And h, the fan power is 90% of rated power.

Preferably, during the third stage cooling: simultaneously air cooling and water cooling for 30 minutes, and the water flow is 55m³And h, the fan power is 90% of rated power.

The zirconium-free blank soaking and cooling method of the 2014 aluminum alloy hub die forging, provided by the invention, comprises 0.65-0.75% of Si, less than or equal to 0.10% of Fe, 4.00-4.40% of Cu, 0.70-0.90% of Mn, 0.45-0.55% of Mg, 0.04-0.07% of Cr, less than or equal to 0.20% of Zn and less than or equal to 0.15% of Ti; in the first stage heating: raising the temperature to 450-480 +/-5 ℃ per hour at 55 +/-5 ℃, and then preserving the temperature for 4.5-5.5 hours at 450 +/-5 ℃; during the second stage of heating: continuing the first-stage heating, raising the temperature by 10 +/-5 ℃ per hour to 505-525 +/-5 ℃, and then preserving the temperature at 505 +/-5 ℃ for 29-35 hours; during the first stage of cooling; continuing the second-stage heating, and air-cooling for 80-100 minutes, wherein the rotation frequency of the fan is 15-30 min/time; in the second stage of cooling: continuing the first stage cooling, simultaneously cooling with air and fog for 80-100 min, rotating frequency of the fan 15-30 min/time, and water flow rate of water for fog cooling 10-20m³H; during the third stage cooling: continuing the second stage cooling, simultaneously cooling with air and water for 25-35 minutes, keeping the fan in non-rotation direction, and controlling water flow at 40-70m³H is used as the reference value. The zirconium-free blank with the components is treated based on the soaking and cooling method, so that the product quality of the 2014 aluminum alloy aviation precise hub die forging can be greatly improvedAmount of the compound (A).

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a schematic side view structure diagram of a 2014 aluminum alloy aviation precision hub die forging provided in an embodiment of the present invention;

FIG. 2 is a second side view structural schematic diagram of the 2014 aluminum alloy aviation precision hub die forging provided in the embodiment of the invention;

FIG. 3 is a schematic view of the first coupon 100 × structure of the sample before soaking;

FIG. 4 is a schematic view of a second specimen 200 × structure of the sample before soaking;

FIG. 5 is a schematic diagram of the core structure of the first specimen of the sample after soaking;

FIG. 6 is a schematic view of the surface structure of the first coupon after soaking;

FIG. 7 is a schematic diagram of the core structure of the second coupon of the sample after soaking;

FIG. 8 is a schematic view of the surface structure of the second coupon after soaking;

FIG. 9 is a schematic view of the structure of the first test strip 50X after cooling;

FIG. 10 is a schematic view of the structure of a first specimen 200X after cooling;

FIG. 11 is a schematic view of the structure of a second test strip 50X after cooling;

FIG. 12 is a schematic view of a second coupon 200 × structure of a sample after cooling;

FIG. 13 is a schematic view of the structure of the third test strip 50X after cooling;

FIG. 14 is a schematic view of a third coupon 200 × structure of a sample after cooling;

FIG. 15 is a schematic view of the structure of the fourth test strip 50X after cooling;

FIG. 16 is a schematic view of the structure of the fourth test strip 200X after cooling.

In the above FIGS. 1-16:

the outer extension part 11, the cylinder 12, the oval pit 13 and the lug 14.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1 to fig. 16, fig. 1 is a first side view structural schematic diagram of an 2014 aluminum alloy aviation precision hub die forging provided in an embodiment of the present invention; FIG. 2 is a second side view structural schematic diagram of the 2014 aluminum alloy aviation precision hub die forging provided in the embodiment of the invention; FIG. 3 is a schematic view of the first coupon 100 × structure of the sample before soaking; FIG. 4 is a schematic view of a second specimen 200 × structure of the sample before soaking; FIG. 5 is a schematic diagram of the core structure of the first specimen of the sample after soaking; FIG. 6 is a schematic view of the surface structure of the first coupon after soaking; FIG. 7 is a schematic diagram of the core structure of the second coupon of the sample after soaking; FIG. 8 is a schematic view of the surface structure of the second coupon after soaking; FIG. 9 is a schematic view of the structure of the first test strip 50X after cooling; FIG. 10 is a schematic view of the structure of a first specimen 200X after cooling; FIG. 11 is a schematic view of the structure of a second test strip 50X after cooling; FIG. 12 is a schematic view of a second coupon 200 × structure of a sample after cooling; FIG. 13 is a schematic view of the structure of the third test strip 50X after cooling; FIG. 14 is a schematic view of a third coupon 200 × structure of a sample after cooling; FIG. 15 is a schematic view of the structure of the fourth test strip 50X after cooling; FIG. 16 is a schematic view of the structure of the fourth test strip 200X after cooling.

The embodiment of the invention provides a zirconium-free blank soaking and cooling method of a 2014 aluminum alloy hub die forging, the zirconium-free blank comprises 0.65-0.75% of Si, less than or equal to 0.10% of Fe, 4.00-4.40% of Cu, 0.70-0.90% of Mn, 0.45-0.55% of Mg, 0.04-0.07% of Cr and less than or equal to Zn0.20 percent of Ti and less than or equal to 0.15 percent of Ti; in the first stage heating: raising the temperature to 450-480 +/-5 ℃ per hour at 55 +/-5 ℃, and then preserving the temperature for 4.5-5.5 hours at 450 +/-5 ℃; during the second stage of heating: continuing the first-stage heating, raising the temperature by 10 +/-5 ℃ per hour to 505-525 +/-5 ℃, and then preserving the temperature at 505 +/-5 ℃ for 29-35 hours; during the first stage of cooling; continuing the second-stage heating, and air-cooling for 80-100 minutes, wherein the rotation frequency of the fan is 15-30 min/time; in the second stage of cooling: continuing the first stage cooling, simultaneously cooling with air and fog for 80-100 min, rotating frequency of the fan 15-30 min/time, and water flow rate of water for fog cooling 10-20m³H; during the third stage cooling: continuing the second stage cooling, simultaneously cooling with air and water for 25-35 minutes, keeping the fan in non-rotation direction, and controlling water flow at 40-70m³H is used as the reference value. The zirconium-free blank with the components is processed based on the soaking and cooling method, so that the product quality of the 2014 aluminum alloy aviation precision hub die forging can be greatly improved.

Wherein, during the first stage heating: raising the temperature to 480 +/-5 ℃ per hour at 55 +/-5 ℃, keeping the temperature for 5-6 hours, and then preserving the temperature for 5 hours at 450 +/-5 ℃. Specifically, during the first stage heating: to 480 + -5 deg.C and held for 5.5 hours.

Wherein, during the second stage of heating: heating to 525 + -5 deg.C per hour at 10 + -5 deg.C for 2-3 hr, and holding at 505 + -5 deg.C for 30 + -5 hr. Specifically, during the second stage heating: keeping the temperature to 525 +/-5 ℃ for 2.5 hours, and keeping the temperature at 505 ℃ for 30 hours.

Specifically, during the first stage heating: keeping the temperature at 450 +/-5 ℃ for 5 hours. During the second stage of heating: keeping the temperature at 505 +/-5 ℃ for 30 hours. During the second stage of heating: keeping the temperature at 505 +/-5 ℃ for 34 hours. In the second stage of cooling: simultaneously cooling by air and mist for 90 min, turning frequency of the fan being 20 min/time, and water flow rate of water for mist cooling being 15m³And h, the fan power is 90% of rated power. During the third stage cooling: simultaneously air cooling and water cooling for 30 minutes, and the water flow is 55m³And h, the fan power is 90% of rated power.

During the specific operation, two soaking systems of high strength and toughness 2014 hub are designed, the soaking system without Zr alloy has two-stage soaking system of 450 deg.C x 5h +505 deg.C x 30h, and the soaking system with Zr alloy has three-stage soaking system of 400 deg.C x 10h +450 deg.C x 5h +505 deg.C x 30 h. From the three-stage soaking regime, the second stage heat preservation 502 ℃ is very close to the third stage 506 ℃. Because all soaking furnaces of a casting plant have large effective working size and large furnace loading amount, the temperature uniformity of the soaking furnaces is lower than that of a laboratory soaking furnace, and fixed-point soaking of temperature cannot be realized. Considering the control range of the uniformity of the soaking furnace per se within +/-5 ℃, the second-level and third-level soaking systems are optimized and adjusted to 505 ℃. According to the laboratory results, the optimized 2014 alloy ingot casting soaking technological parameters for the hub are determined and are shown in table 1. Table 1 shows 2014 hub soaking process regime.

Watch 12014 hub soaking process system

In order to investigate the influence of cooling after homogenization on the ingot casting performance, the ingot casting is discharged from the furnace for air cooling for the first time, and discharged from the furnace for the second time and enters the rapid cooling furnace for water cooling. And (5) making a cooling process system.

2014 hub must have high strength and toughness properties, so more uniform dispersion strengthening phase needs to be obtained. By taking the quick soaking and cooling process adopted by the 6005 subway section bar as a reference, the optimal amount soaking and cooling process is finally determined by optimizing the matching cooling mode, the cooling water flow and the fan steering frequency, as shown in table 2. Table 2 shows the 2014 hub post soak cooling schedule.

Meter 22014 wheel hub soaking after-cooling system

The actual soaking situation is shown in table 3, table 3 is 2014 the actual soaking situation of the hub,

table 32014 wheel hub actual soaking condition

After soaking in the heat of the table 3, directly discharging from the furnace for air cooling, cutting the specimen to observe the high power structure of the ingot, as shown in fig. 3-8, fig. 3 is a schematic diagram of 100 x structure of the first specimen of the sample before soaking, fig. 4 is a schematic diagram of 200 x structure of the second specimen of the sample before soaking, fig. 5 is a schematic diagram of the core structure of the first specimen of the sample after soaking, fig. 6 is a schematic diagram of the surface layer structure of the first specimen of the sample after soaking, fig. 7 is a schematic diagram of the core structure of the second specimen of the sample after soaking, and fig. 8 is a schematic diagram of the surface layer structure of the second specimen of the sample after soaking.

And the other cooling is to perform soaking on the cast ingot according to the table 3, perform cooling according to the table 4 after the soaking is finished, wherein the table 4 is the actual cooling condition of the 2014 hub, and the temperature in the cooling process is shown in the table 5.

TABLE 42014 actual hub Cooling conditions

TABLE 52014 Metal temperature for practical hub Cooling

As can be seen from Table 5, the cooling process was performed according to the process schedule, and the time from the completion of soaking to the start of the cooling process of the cooling furnace was long, and the temperature drop was large and reached 111 ℃. In the cooling process, the temperature of an air cooling stage is decreased by 237 ℃, the temperature of an air cooling and fog cooling stage is decreased by 127 ℃, and the temperature of a water cooling stage is decreased by 12 ℃. Fig. 9-16 show the high magnification observation of the sliced specimen, fig. 9 is a schematic diagram of the structure of the first specimen 50 × after cooling, fig. 10 is a schematic diagram of the structure of the first specimen 200 × after cooling, fig. 11 is a schematic diagram of the structure of the second specimen 50 × after cooling, fig. 12 is a schematic diagram of the structure of the second specimen 200 × after cooling, fig. 13 is a schematic diagram of the structure of the third specimen 50 × after cooling, fig. 14 is a schematic diagram of the structure of the third specimen 200 × after cooling, fig. 15 is a schematic diagram of the structure of the fourth specimen 50 × after cooling, and fig. 16 is a schematic diagram of the structure of the fourth specimen 200 × after cooling.

The results of the energy spectrum of the grain boundary compound of the first test piece of the sample after cooling are shown in table 6, and table 6 shows the results of the energy spectrum of the grain boundary compound of the first test piece of the sample after cooling. The results of the energy spectrum of the grain boundary compound of the second test piece of the sample after cooling are shown in table 7, and table 7 shows the results of the energy spectrum of the grain boundary compound of the second test piece of the sample after cooling. The results of the energy spectra of the grain boundary compounds of the third test piece of the sample after cooling are shown in table 8, and table 8 shows the results of the energy spectra of the grain boundary compounds of the third test piece of the sample after cooling. The results of the energy spectrum of the grain boundary compound of the fourth test piece of the sample after cooling are shown in table 9, and table 9 shows the results of the energy spectrum of the grain boundary compound of the fourth test piece of the sample after cooling.

TABLE 6 energy spectra of grain boundary compounds of the first test piece of the sample after cooling

TABLE 7 energy spectra of grain boundary compounds of the second coupon of the sample after cooling

TABLE 8 energy spectra of grain boundary compounds of the third test piece of the sample after cooling

TABLE 9 energy spectra of grain boundary compounds of the fourth test piece of the sample after cooling

A sample at the hot end is cut, a gate part test piece and a bottom test piece are prepared into tensile samples in the cast state and the soaking cooling state of cast ingots, the tensile test is carried out by using CMT5105 equipment at the ambient temperature of 20.0 ℃ according to the GB/T228.1-2010 experimental method, the results are shown in Table 10, and the Table 10 shows the tensile property results. As can be seen from the table: under the same state, the tensile strength of two ends of the same ingot is the same; the tensile strength in the as-cast state is slightly higher than in the soaking cooled state. Under the same state, the bottom of the same ingot extends to be higher than the gate part; the elongation in the soaking cooling state is far higher than that in the cast state and is 2.7 times of that in the cast state.

TABLE 10 tensile Properties

The hot end was cut out, and the conductivity test was conducted on the bottom test piece of another sample of the ingot in the as-cast state and soaking-cooled state, and the results are shown in table 11 and table 10. As can be seen from the table: the conductivity in the fast-cooling state is obviously higher than that in the cast state and is 1.63 times that in the cast state. After homogenization treatment, solute elements in the supersaturated solid solution are reduced, a large number of second phase particles are precipitated from the alloy, and the supersaturated solid solubility in the matrix is reduced, so that the resistivity of the alloy is reduced, and the conductivity is increased. Meanwhile, the conductivities of all points are basically consistent in the same state, which indicates that the segregation of the alloy element regions is very small.

TABLE 11 conductivity test

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.