阅读说明：本技术 一种高强度铝合金铸锭及其制备方法 (High-strength aluminum alloy ingot and preparation method thereof ) 是由 朱敏 陈向富 于 2020-12-11 设计创作，主要内容包括：本发明提供了一种高强度铝合金铸锭的制备方法,包括：将合金原料进行熔炼和铸造,得到高强度铝合金铸锭；所述合金原料包括铝锭,所述铝锭中Fe和Si总的质量含量≤0.1％。本发明取消炉前Al-Ti中间合金的加入,在提高铸锭断口氧化膜合格率的同时降低生产成本；控制Fe、Si杂质含量,生产的合金铸锭所产生的几何废料可用于其他合金的生产,提高几何废料使用效率,且可以提高铸锭探伤合格率；控制熔体氢含量,可大大降低铸锭疏松尺寸,提高铸锭断口氧化膜合格率及探伤合格率。本发明提供的制备方法能够使铸锭探伤及断口氧化膜合格率稳定控制在98％以上。(The invention provides a preparation method of a high-strength aluminum alloy ingot, which comprises the following steps: smelting and casting the alloy raw material to obtain a high-strength aluminum alloy ingot; the alloy raw material comprises an aluminum ingot, and the total mass content of Fe and Si in the aluminum ingot is less than or equal to 0.1%. According to the invention, the addition of Al-Ti intermediate alloy in front of the furnace is cancelled, so that the yield of the oxide film at the fracture of the ingot is improved, and the production cost is reduced; the impurity content of Fe and Si is controlled, the geometric waste generated by the produced alloy ingot can be used for producing other alloys, the use efficiency of the geometric waste is improved, and the flaw detection qualification rate of the ingot can be improved; the hydrogen content of the melt is controlled, the loosening size of the cast ingot can be greatly reduced, and the qualification rate of the oxide film at the fracture of the cast ingot and the qualification rate of flaw detection are improved. The preparation method provided by the invention can stably control the qualification rate of flaw detection of the cast ingot and the oxide film at the fracture over 98 percent.)

1. A preparation method of a high-strength aluminum alloy ingot comprises the following steps:

smelting and casting the alloy raw material to obtain a high-strength aluminum alloy ingot;

the alloy raw material comprises an aluminum ingot, and the total mass content of Fe and Si in the aluminum ingot is less than or equal to 0.1%.

2. The method of claim 1, wherein the aluminum ingot has a taste of 99.93 to 99.97%.

3. A method according to claim 1, wherein the mass content of Fe in the aluminum ingot is 0.002 to 0.04%.

4. The method according to claim 1, wherein the mass content of Si in the aluminum ingot is 0.01 to 0.03%.

5. The method of claim 1, wherein the alloy feedstock does not contain an Al-Ti master alloy.

6. The method of claim 1, wherein no Al-Ti master alloy is added during the smelting process.

7. The method according to claim 1, characterized in that in-line degassing is performed during the casting process, and the degassing method is Alpur rotary degassing.

8. The method of claim 7, wherein the melt obtained after degassing has a hydrogen content of 0.08ml/100g.Al or less.

9. The method of claim 1, wherein a refiner is added during the casting; the refiner comprises Al-Ti-B refiner and Al-Ti-C refiner.

10. A high strength aluminum alloy ingot produced by the method of claim 1; the high-strength aluminum alloy cast ingot comprises the following components:

0.01 to 0.04 wt% of Si;

0.03 to 0.07 wt% Fe;

2.05-2.30 wt% of Cu;

0.01 to 0.02 wt% of Mn;

2.00-2.25 wt% of Mg;

0.01-0.02 wt% of Cr;

6.10-6.50 wt% of Zn;

0.01 to 0.03 wt% of Ti; 0.09-0.11 wt% of Zr;

impurities are less than or equal to 0.20 wt%;

the balance being Al.

Technical Field

The invention belongs to the technical field of aluminum alloy, and particularly relates to a high-strength aluminum alloy ingot and a preparation method thereof.

Background

The method is characterized in that the production is carried out according to the conventional high-strength aluminum alloy cast ingot, only chemical components are controlled to meet the technical standard requirement, Ti elements in the prepared cast ingot are gathered and inherited to a plate, Ti-containing impurities appear at a fracture of the plate, and the percent of pass of an oxide film at the fracture of the cast ingot is influenced (currently, the percent of pass is less than 93%); the produced ingot contains more Fe and Si compounds and is large in porosity, and the flaw detection qualification rate of the ingot is influenced (less than 92 percent at present). In the prior art, the qualification rate of an oxide film at a fracture of an ingot and the qualification rate of flaw detection are low due to unstable control of hydrogen content in the prepared high-strength aluminum alloy melt, so that the use requirements of users are influenced; at present, the yield of the alloy cast ingot is only 68.58 percent and is still at a lower level, and in order to meet the market requirement of rapid development, the yield and the metallurgical quality of the alloy need to be improved urgently.

Disclosure of Invention

In view of the above, the invention aims to provide a high-strength aluminum alloy ingot and a preparation method thereof, and the yield of oxide films at fractures and the yield of flaw detection of the aluminum alloy ingot prepared by the method provided by the invention are high.

The invention provides a preparation method of a high-strength aluminum alloy ingot, which comprises the following steps:

smelting and casting the alloy raw material to obtain a high-strength aluminum alloy ingot;

the alloy raw material comprises an aluminum ingot, and the total mass content of Fe and Si in the aluminum ingot is less than or equal to 0.1%.

Preferably, the aluminum ingot has a taste of 99.93 to 99.97%.

Preferably, the mass content of Fe in the aluminum ingot is 0.002-0.04%.

Preferably, the mass content of Si in the aluminum ingot is 0.01-0.03%.

Preferably, the alloy raw material does not contain an Al-Ti intermediate alloy.

Preferably, no Al-Ti intermediate alloy is added in the smelting process.

Preferably, degassing is performed in the casting process, and the degassing method is Alpur rotary degassing.

Preferably, the hydrogen content in the melt obtained after degassing is less than or equal to 0.08ml/100g.

Preferably, the casting process is added with a refiner, and the refiner comprises an Al-Ti-B refiner and an Al-Ti-C refiner.

The invention provides a high-strength aluminum alloy cast ingot prepared by the method in the technical scheme; the high-strength aluminum alloy cast ingot comprises the following components:

0.01 to 0.04 wt% of Si;

0.03 to 0.07 wt% Fe;

2.05-2.30 wt% of Cu;

0.01 to 0.02 wt% of Mn;

2.00-2.25 wt% of Mg;

0.01-0.02 wt% of Cr;

6.10-6.50 wt% of Zn;

0.01 to 0.03 wt% of Ti;

0.09-0.11 wt% of Zr;

impurities are less than or equal to 0.20 wt%;

the balance being Al.

According to the invention, the addition of a stokehole Al-Ti intermediate alloy is cancelled, an aluminum ingot with low impurity content is selected, the Fe + Si content is controlled to be less than or equal to 0.10%, the hydrogen content of the melt is controlled to be less than or equal to 0.08ml/100g.Al, Al-Ti-B and Al-Ti-C combined refining is adopted, and the production cost is reduced while the qualified rate of an oxide film at a fracture of the ingot is improved by cancelling the addition of the stokehole Al-Ti intermediate alloy; the impurity content of Fe and Si is controlled, the geometric waste generated by alloy ingot production can be used for producing other alloys, the use efficiency of the geometric waste is improved, and the flaw detection qualification rate of the ingot can be improved; the hydrogen content of the melt is controlled, the loosening size of the cast ingot can be greatly reduced, and the qualification rate of the oxide film at the fracture of the cast ingot and the qualification rate of flaw detection are improved. The preparation method provided by the invention can stably control the qualification rate of flaw detection of the cast ingot and the oxide film at the fracture over 98 percent.

Drawings

FIG. 1 shows the fracture morphology of the aluminum alloy ingot prepared in comparative example 1 of the present invention, which contains a large amount of Ti-containing particles, and greatly affects the fracture yield of the alloy;

FIG. 2 shows the fracture morphology of the aluminum alloy ingot prepared in example 1 of the present invention, wherein the fracture has a clear and clean tough pit shape;

FIG. 3 shows the loose morphology of the aluminum alloy ingot prepared in comparative example 1, the loose size is large and the quantity is large, the subsequent processing deformation is not easy to weld, and the flaw detection and fracture yield of the alloy ingot are greatly influenced;

FIG. 4 shows the loose morphology, the loose size and the small amount of the aluminum alloy ingots prepared in example 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other examples, which may be modified or appreciated by those of ordinary skill in the art based on the examples given herein, are intended to be within the scope of the present invention. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention. In the examples, the methods used were all conventional methods unless otherwise specified.

The invention provides a preparation method of a high-strength aluminum alloy ingot, which comprises the following steps:

smelting and casting the alloy raw material to obtain a high-strength aluminum alloy ingot;

the alloy raw material comprises an aluminum ingot, and the total mass content of Fe and Si in the aluminum ingot is less than or equal to 0.1%.

In the present invention, the alloy raw material preferably includes an aluminum ingot.

In the invention, the taste of the aluminum ingot is preferably 99.93-99.97%, more preferably 99.94-99.96%, and most preferably 99.95%; the mass content of Fe in the aluminum ingot is preferably 0.002-0.04%, more preferably 0.01-0.03%, and most preferably 0.02%; the mass content of Si in the aluminum ingot is preferably 0.01-0.03%, and more preferably 0.02%; the total content of Fe and Si in the aluminum ingot is preferably less than or equal to 0.1 percent.

In the present invention, the alloy raw material preferably further includes scrap.

In the present invention, the mass content of the scrap in the alloy raw material is preferably not more than 60%, more preferably 10 to 50%, and most preferably 20 to 40%. In the invention, the mass content of Fe in the waste is preferably 0.02-0.04%, and more preferably 0.03%; the mass content of Si in the waste is preferably 0.01-0.03%, and more preferably 0.02%; the mass content of Ti in the waste is preferably 0.01-0.02%, and more preferably 0.01%.

In the present invention, the scrap preferably contains elements such as Si, Fe, Cu, Mg, Zn, Ti, etc.; the composition of the waste material is preferably:

0.01 to 0.03 wt% of Si;

0.02 to 0.04 wt% Fe;

2.05-2.30 wt% of Cu;

mn less than or equal to 0.01 wt%;

2.00-2.25 wt% of Mg;

cr of less than or equal to 0.01 wt%;

6.10-6.50 wt% of Zn;

less than or equal to 0.03 wt% of Ti;

0.09-0.11 wt% of Zr;

the balance being Al.

In the present invention, the mass content of Si is preferably 0.02%; the mass content of the Fe is preferably 0.03%; the mass content of Cu is preferably 2.10-2.25%, and more preferably 2.15-2.20%; the mass content of Mn is preferably 0.001-0.008%, more preferably 0.003-0.006%, and most preferably 0.004-0.005%; the mass content of Mg is preferably 2.05-2.20%, and more preferably 2.10-2.15%; the mass content of Cr is preferably 0.001-0.008%, more preferably 0.003-0.006%, and most preferably 0.004-0.005%; the mass content of Zn is preferably 6.20-6.40%, and more preferably 6.30%; the mass content of Ti is preferably 0.01-0.03%, and more preferably 0.02%; the mass content of Zr is preferably 0.10%.

In the invention, the waste materials are preferably from the cut gate part and the bottom stub bar when the high-strength aluminum alloy cast ingot is prepared by the method provided by the invention.

In the present invention, the alloy raw materials preferably further include a Cu plate, an Mg ingot, a Zn ingot, and an Al — Zr intermediate alloy.

In the present invention, Mg ingots and Zn ingots having clean appearance, no oil stain, and no dross on the surface are preferable, and Cu plates having good color and no Cu rust are preferable.

In the invention, the alloy raw materials are preferably mixed and then smelted, the method for mixing is not particularly limited, and a person skilled in the art can mix the alloy raw materials according to the components of the alloy ingot and the components of the alloy raw materials to prepare the aluminum alloy ingot with the required components. In the present invention, it is preferable that no Al — Ti master alloy is added in the batching process. In the present invention, the ingredients are preferably such that the alloy raw materials have the following compositions:

0.03 to 0.04 wt% of Si;

0.05 to 0.07 wt% of Fe;

2.05-2.30 wt% of Cu;

0.01 to 0.02 wt% of Mn;

2.00-2.25 wt% of Mg;

0.01-0.02 wt% of Cr;

6.10-6.50 wt% of Zn;

0.01 to 0.04 wt% of Ti;

0.09-0.11 wt% of Zr;

the balance being Al.

In the present invention, the mass content of Si is preferably 0.04%; the mass content of Fe is preferably 0.06%; the mass content of Cu is preferably 2.10-2.25%, and more preferably 2.15-2.20%; the mass content of Mn is preferably 0.02%; the mass content of Mg is preferably 2.05-2.20%, and more preferably 2.10-2.15%; the mass content of Cr is preferably 0.02%; the mass content of Zn is preferably 6.20-6.40%, and more preferably 6.30%; the mass content of Ti is preferably 0.02%; the mass content of Zr is preferably 0.10%.

In the present invention, the method for smelting preferably includes:

charging, smelting temperature control and discharging temperature control.

In the present invention, the charging method preferably includes:

the intermediate alloy such as Cu plate, Mg ingot, Zn ingot and Al-Zr is not added with the furnace, when the furnace burden (aluminum ingot and waste) is melted with a layer of liquid metal, the Cu plate and the Zn ingot are added, and the liquid level is strictly prevented from being exposed or clinging to the furnace bottom; when the temperature is increased to 740-760 ℃, adding the Al-Zr intermediate alloy and the Mg ingot, wherein the temperature is preferably increased to 745-755 ℃, and more preferably 750 ℃.

In the invention, the smelting temperature is preferably not more than 1050 ℃, more preferably 1010-1040 ℃, and more preferably 1020-1030 ℃. In the present invention, the method for controlling the melting temperature preferably includes: when the melt is melted and stirred, a metal temperature measuring couple is inserted, the temperature is automatically controlled by the metal, the molten metal is stirred timely, and the melt is prevented from being locally overheated.

In the invention, the tapping temperature is preferably controlled to be 740-760 ℃, more preferably 745-755 ℃ and most preferably 750 ℃.

In the invention, Al-Ti intermediate alloy is preferably not used in the burdening and smelting processes, and Ti is not supplemented in the burdening and smelting processes, so that the fracture yield of the prepared high-strength aluminum alloy ingot can be improved.

In the present invention, the smelting process preferably further includes: thoroughly stirring for 2 times before flowing from the smelting furnace to the standing furnace after the smelting is finished, wherein the melt temperature is preferably controlled to be 740-760 ℃, more preferably 745-755 ℃ and most preferably 750 ℃ during the converter; preferably, 0.23-0.28 kg/t of molten metal of Al-Be intermediate alloy is uniformly added into a converter launder, wherein the addition amount of the Al-Be intermediate alloy is preferably 0.24-0.26 kg/t of molten metal, and more preferably 0.25kg/t of molten metal; the Al-Be intermediate alloy is preferably added in the invention to form a compact oxide film with the melt during tapping so as to prevent the hydrogen absorption of the melt by air suction.

In the invention, the smelting process preferably further comprises artificial refining, and the artificial refining is carried out in a standing furnace; the time for the artificial refining is preferably 30-45 minutes, and more preferably 35-40 minutes. In the present invention, the method of artificial refining preferably comprises:

introducing Ar gas and Cl by using a refiner₂Refining the gas mixture.

In the present invention, the refiner is preferably a "T" type refiner.

In the present invention, the Ar gas and Cl₂The volume ratio of the gas is preferably (80-120): 1, more preferably (90-110): 1, most preferably 100: 1.

in the invention, the height of bubbles in the melt in the artificial refining process is preferably less than or equal to 80mm, more preferably 10-80 mm, more preferably 20-70 mm, more preferably 30-60 mm, and most preferably 40-50 mm.

In the invention, degassing is carried out in the casting process, and the degassing method is preferably Alpur rotary degassing, and more preferably double-rotor Alpur rotary online degassing. In the invention, the double-rotor Alpur rotary degassing adopts Ar gas and Cl₂Removing hydrogen in the melt by using mixed gas, wherein the gas pressure in the Alpur rotary degassing process is preferably 0.1-0.3 MPa, and more preferably 0.2 MPa; the rotating speed of the rotor is preferably 230-270 rpm, more preferably 240-260 rpm, and most preferably 250 rpm; the flow rate of Ar gas is preferably 3.0-5.0 Nm³More preferably 3.5 to 4.5 Nm/h³H, most preferably 4Nm³/h；Cl₂The flow rate of the gas is preferably 0.03-0.06 Nm³More preferably 0.04 to 0.05 Nm/h³/h。

In the invention, the content of hydrogen in the melt obtained after degassing is preferably less than or equal to 0.08ml/100g.Al, more preferably 0.05-0.08 ml/100g.Al, and most preferably 0.05-0.07 ml/100 g.Al.

In the present invention, it is preferable that the degassing is completed by further including:

and filtering the degassed melt.

In the present invention, the filtration is preferably performed using a filter plate, more preferably a 40PPI +60PPI filter plate dual-stage filtration; the melt temperature in the filtering process is preferably 710-730 ℃, more preferably 715-725 ℃, and most preferably 720 ℃.

In the present invention, it is preferable to add a refiner during the casting, and the refiner preferably includes an Al-Ti-C refiner and an Al-Ti-B refiner. The principle of the refiner is TiAl₃Is unstable and easy to dissolve in aluminum melt, and solute Ti atoms are easy to be oriented to TiB₂Or TiC particles are enriched, and the Ti-rich surface layer is subjected to peritectic reaction in subsequent cooling to nucleate alpha-Al, so that the effect of heterogeneous nucleation and grain refinement is achieved. In the invention, Al-Ti-C wire refiner is independently adopted for refining, compounds are easy to agglomerate and gather at the trifurcate crystal boundary junction, and Al-Ti-B wire refiner is independently adopted for refining, so that 'transverse impact' is easy to formThe invention obtains alloy cast ingots with compound dispersed in the structure by Al-Ti-B and Al-Ti-C combined refinement of the straight-collision needle-shaped compound, and improves the flaw detection qualification rate of the cast ingots.

In the present invention, the Al-Ti-C refiner is preferably Al-3 Ti-1B; the Al-Ti-C refiner is preferably Al-3 Ti-0.15C. In the present invention, the mass ratio of the Al-Ti-C refiner to the Al-Ti-B refiner is preferably 1: (1-2), more preferably 1 (1-1.5), most preferably 1: 1; the addition amount of the Al-Ti-C refiner is preferably 1.0-1.6 kg/t of molten metal, more preferably 1.2-1.5 kg/t of molten metal, and most preferably 1.3-1.4 kg/t of molten metal; the addition amount of the Al-Ti-B refiner is preferably 1.2-2.0 kg/t of molten metal, more preferably 1.4-1.8 kg/t of molten metal, and most preferably 1.5-1.6 kg/t of molten metal; the invention preferably adopts 1.6kg/t of molten metal of Al-Ti-C refiner and 1.6kg/t of molten metal of Al-Ti-B refiner for combined refining.

In the invention, the casting speed in the casting process is preferably 45-50 mm/min, and more preferably 46-48 mm/min; the water flow is preferably 70-90 m³More preferably 75 to 85m³H, most preferably 80m³H; the casting temperature is preferably 725-745 ℃, more preferably 730-740 ℃, and most preferably 735 ℃; the lower injection pipe temperature is preferably 690-710 ℃, more preferably 695-705 ℃, and most preferably 700 ℃; the wiper position is preferably 350 to 410mm, more preferably 360 to 400mm, more preferably 370 to 390mm, and most preferably 380 mm.

In the present invention, after the casting, the casting preferably further comprises a step of soaking the obtained ingot, and the soaking method preferably comprises:

heating the cast ingot to 390-410 ℃ and preserving heat for 8-12 hours, and then heating to 460-480 ℃ and preserving heat for 45-50 hours.

In the invention, the heating temperature is preferably 395-405 ℃, more preferably 400 ℃, and the heat preservation time is preferably 9-11 hours, more preferably 10 hours; the reheating temperature is preferably 465-475 ℃, more preferably 470 ℃, and the heat preservation time is preferably 46-49 hours, more preferably 48 hours.

In the present invention, it is preferable that the soaking further comprises:

and processing the soaked product.

In the present invention, the method of processing preferably includes:

and cutting the alloy ingot after soaking into 250-350 mm of a gate part, preferably 280-320 mm, more preferably 300mm, and 350-450 mm of a bottom part, preferably 380-420 mm, and most preferably 400 mm.

In the present invention, the material of the cut gate portion and the bottom portion obtained after the processing is preferably scrap material used as an alloy raw material for producing a high-strength aluminum alloy ingot in the present invention.

According to the invention, the addition of a stokehole Al-Ti intermediate alloy is cancelled, an aluminum ingot with low impurity content is selected, the Fe + Si content is controlled to be less than or equal to 0.10%, the hydrogen content of the melt is controlled to be less than or equal to 0.08ml/100g.Al, Al-Ti-B and Al-Ti-C combined refining is adopted, and the production cost is reduced while the qualified rate of an oxide film at a fracture of the ingot is improved by cancelling the addition of the stokehole Al-Ti intermediate alloy; the impurity content of Fe and Si is controlled, the geometric waste generated by alloy ingot production can be used for producing other alloys, the use efficiency of the geometric waste is improved, and the flaw detection qualification rate of the ingot can be improved; the hydrogen content of the melt is controlled, the loosening size of the cast ingot can be greatly reduced, and the qualification rate of the oxide film at the fracture of the cast ingot and the qualification rate of flaw detection are improved. The preparation method provided by the invention can stably control the qualification rate of flaw detection of the cast ingot and the oxide film at the fracture over 98 percent.

In the following examples of the present invention, the raw materials are all commercially available products, the aluminum ingot used is 99.95% type aluminum ingot provided by baotou aluminum industries, the Al-Ti-B refiner used is Al-3Ti-1B type product provided by spanish KMG, the Al-Ti-C refiner used is Al-3Ti-0.15C type product provided by spanish KMG, and the used scrap (the gate cut portion and the bottom stub when preparing the high strength aluminum alloy ingot of the present invention) has the compositions shown in table 1:

TABLE 1 composition in wt% of the waste materials used in the examples of the present invention

Example 1

The high-strength aluminum alloy cast ingot is prepared according to the following method:

sequentially carrying out material preparation, smelting, online treatment, casting, soaking, processing and sending.

Preparing materials:

the alloy is prepared by using 99.95 percent of Al ingot, intermediate alloy or pure metal, primary waste and the like, wherein the use proportion of the waste is less than or equal to 60 percent, Ti is not added in the whole process, and the chemical components of the alloy raw materials are controlled according to the following table 1.

Table 1 alloy raw material compounding ingredient control of inventive example 1

Smelting:

when a smelting furnace is used for charging, a Zn ingot, a Cu plate, an Mg ingot, an Al-Zr intermediate alloy and an Al-Be intermediate alloy are not added along with the furnace; when a layer of liquid metal is melted in furnace burden (aluminum ingot and waste material), uniformly adding a Cu plate and a Zn ingot, and strictly preventing the furnace burden from exposing the liquid level or clinging to the furnace bottom; when the metal temperature is raised to 750 ℃, adding Al-Zr intermediate alloy and Mg ingots, and uniformly stirring by using a forklift; and adding Al-Zr intermediate alloy and then preserving heat for 40 min.

When the alloy is smelted, the hearth temperature is 1040 ℃, when the melt is melted and stirred evenly, a metal temperature measuring couple is inserted, the temperature is automatically controlled by the metal, and the set value of the metal temperature is set to be 750 ℃; stirring the molten metal at proper time to prevent the melt from being locally overheated; during the time the melt temperature reached 740 ℃, a sample was taken for chemical analysis.

Thoroughly stirring the melt twice before the melt is discharged from the standing furnace from the smelting furnace, controlling the temperature of the melt at 750 ℃ during the converter, and uniformly adding 0.24kg/t of Al-Be intermediate alloy of molten metal into a launder of the converter.

And (3) online processing:

after smelting, the online melt is processed online by an Alpur rotary degassing device, and the refining gas is Ar gas and Cl₂The specific parameters of the gas mixture are shown in table 2:

TABLE 2 Process parameters for the on-line treatment of inventive example 1

The melt after degassing is filtered in two stages by a 40PPI +60PPI filter plate on line, and the melt temperature in the filter device is 720 ℃.

Casting:

the process parameters during casting were controlled as per table 3:

TABLE 3 Process parameters for casting according to the invention in example 1

Adding 1.6kg/t of metal liquid of Al-3Ti-0.15C refiner and 1.6kg/t of metal liquid of Al-3Ti-1B refiner for combined refining.

Soaking the raw materials:

and (3) carrying out soaking treatment on the cast ingot obtained after casting, heating the cast ingot to 400 ℃, preserving heat for 10 hours, and then heating to 470 ℃, and preserving heat for 48 hours.

Processing:

and cutting the alloy ingot after soaking into a gate part of 300mm and a bottom part of 400mm to obtain the high-strength aluminum alloy ingot.

According to GB/T20975 chemical component analysis method of aluminum and aluminum alloy, the components of the high-strength aluminum alloy ingot prepared in the embodiment 1 of the invention are detected, and the detection results are shown in Table 4:

table 4 composition of high-strength aluminum alloy ingot produced in example 1 of the present invention

According to GB/T6519 ultrasonic inspection method for wrought aluminum and magnesium alloy products, 30 aluminum alloy ingots are prepared for multiple times according to the method of example 1, and are subjected to flaw detection qualification rate detection, wherein detection results are all qualified, and the qualification rate is 100%.

According to GB/T3246.2 organization inspection method for wrought aluminum and aluminum alloy products, 30 aluminum alloy ingots are obtained by the method of example 1 for multiple times, and fracture oxide film qualification rate is detected to be 99.96%.

The high-strength aluminum alloy ingot prepared in example 1 of the present invention was cut, SEM detection was performed on the cut fracture, and the detection result is shown in fig. 2, which shows that the fracture is in a clear and clean dimple shape.

The high-strength aluminum alloy ingot prepared in example 1 of the present invention was cut, and metallographic structure detection was performed on the cut, and the detection results are shown in fig. 4, which indicates that the ingot was small in loose size and small in number.

Example 2

The high-strength aluminum alloy cast ingot is prepared according to the following method:

sequentially carrying out material preparation, smelting, online treatment, casting, soaking, processing and sending.

Preparing materials:

the alloy is prepared by using 99.95 percent of Al ingot, intermediate alloy or pure metal, primary waste and the like, wherein the use proportion of the waste is less than or equal to 60 percent, Ti is not added in the whole process, and the chemical components of the alloy raw materials are controlled according to the table 1.

Smelting:

when a smelting furnace is used for charging, a Zn ingot, a Cu plate, an Mg ingot, an Al-Zr intermediate alloy and an Al-Be intermediate alloy are not added along with the furnace; when a layer of liquid metal is melted in furnace burden (aluminum ingot and waste material), uniformly adding a Cu plate and a Zn ingot, and strictly preventing the furnace burden from exposing the liquid level or clinging to the furnace bottom; when the metal temperature is increased to 740 ℃, adding Al-Zr intermediate alloy and Mg ingots, and uniformly stirring by using a forklift; the heat preservation time is 50min after the Al-Zr intermediate alloy is added.

When the alloy is smelted, the hearth temperature is 1045 ℃, when the melt is melted and stirred evenly, a metal temperature measuring couple is inserted, the temperature is automatically controlled by transferring to metal, and the set value of the metal temperature is set to 750 ℃; stirring the molten metal at proper time to prevent the melt from being locally overheated, and sampling and analyzing chemical components when the melt temperature reaches 730 ℃.

Thoroughly stirring the melt twice before the melt is discharged from the standing furnace from the smelting furnace, controlling the temperature of the melt at 740 ℃ during the converter, and uniformly adding 0.23kg/t of Al-Be intermediate alloy of molten metal into a launder of the converter.

And (3) online processing:

after smelting, the online melt is processed online by an Alpur rotary degassing device, and the refining gas is Ar + Cl₂The specific parameters of the mixed gas are shown in table 5:

TABLE 5 Process parameters for the on-line treatment of inventive example 2

The melt after degassing is filtered in two stages by a 40PPI +60PPI filter plate on line, and the melt temperature in the filter device is 710 ℃.

Casting:

the process parameters during casting were controlled as per table 6:

TABLE 6 Process parameters for casting according to the invention in example 2

Adding Al-3Ti-0.15C refiner 1.2kg/t molten metal and Al-3Ti-1B refiner 1.2kg/t molten metal for combined refining.

Soaking the raw materials:

and (3) carrying out soaking treatment on the cast ingot obtained after casting, heating the cast ingot to 400 ℃, preserving heat for 10 hours, and then heating to 470 ℃, and preserving heat for 48 hours.

Processing:

and cutting the alloy ingot after soaking into a gate part of 300mm and a bottom part of 400mm to obtain the high-strength aluminum alloy ingot.

The high strength aluminum alloy prepared in example 2 of the present invention was subjected to composition measurement in accordance with the method of example 1, and the measurement results are shown in table 7:

TABLE 7 composition of high-Strength aluminum alloy ingots prepared in inventive example 2

According to the method of the embodiment 1, 32 aluminum alloy ingots prepared by the method of the embodiment 2 are subjected to flaw detection qualification rate detection, and all detection results are qualified, wherein the qualification rate is 100%; and (4) detecting the qualified rate of the fracture oxide film, wherein the detection result is completely qualified, and the qualified rate is 100%.

Example 3

The high-strength aluminum alloy cast ingot is prepared according to the following method:

proportioning, smelting, on-line treatment, casting, soaking, processing and sending.

Preparing materials:

the alloy is prepared by using 99.95 percent of Al ingot, intermediate alloy or pure metal, primary waste and the like, wherein the use proportion of the waste is less than or equal to 60 percent, Ti is not added in the whole process, and the chemical components of the alloy raw materials are controlled according to the table 1.

Smelting:

when a smelting furnace is used for charging, a Zn ingot, a Cu plate, an Mg ingot, an Al-Zr intermediate alloy and an Al-Be intermediate alloy are not added along with the furnace; when a layer of liquid metal is melted in furnace burden (aluminum ingot and waste material), uniformly adding a Cu plate and a Zn ingot, and strictly preventing the furnace burden from exposing the liquid level or clinging to the furnace bottom; when the metal temperature is raised to 760 ℃, adding Al-Zr intermediate alloy and Mg ingots, and uniformly stirring by using a forklift; the heat preservation time is 45min after the Al-Zr intermediate alloy is added.

When the alloy is smelted, the hearth temperature is 1045 ℃, when the melt is melted and stirred evenly, a metal temperature measuring couple is inserted, the temperature is automatically controlled by transferring to metal, and the set value of the metal temperature is set to 750 ℃; the molten metal is stirred timely to prevent the melt from being overheated locally, the temperature of the melt reaches 745 ℃, and sampling is carried out to analyze chemical components.

Thoroughly stirring the melt twice before the melt is discharged from the standing furnace from the smelting furnace, controlling the temperature of the melt at 760 ℃ during the converter, and uniformly adding 0.28kg/t of Al-Be intermediate alloy of molten metal into a launder of the converter.

And (3) online processing:

after smelting, the online melt is processed online by an Alpur rotary degassing device, and the refining gas is Ar + Cl₂The specific parameters of the mixed gas are shown in table 8:

TABLE 8 Process parameters for casting according to the invention in example 3

The melt after degassing is filtered in two stages by a 40PPI +60PPI filter plate on line, and the melt temperature in the filter device is 730 ℃.

Casting:

the process parameters during casting were controlled as per table 9:

TABLE 9 Process parameters for casting according to the invention in example 3

Adding Al-3Ti-0.15C refiner 1.0kg/t molten metal and Al-3Ti-1B refiner 1.5kg/t molten metal for combined refining.

Soaking the raw materials:

and (3) carrying out soaking treatment on the cast ingot obtained after casting, heating the cast ingot to 400 ℃, preserving heat for 10 hours, and then heating to 470 ℃, and preserving heat for 48 hours.

Processing:

and cutting the alloy ingot after soaking into a gate part of 300mm and a bottom part of 400mm to obtain the high-strength aluminum alloy ingot.

The high strength aluminum alloy of example 3 of the present invention was subjected to composition measurement in accordance with the method of example 1, and the measurement results are shown in table 10:

TABLE 10 composition of high-Strength aluminum alloy ingots prepared in inventive example 3

According to the method of the embodiment 1, the 24 aluminum alloy ingots prepared by the method of the embodiment 2 are subjected to flaw detection qualification rate detection, and the detection results are all qualified, wherein the qualification rate is 100%; and (4) detecting the qualified rate of the fracture oxide film, wherein the detection result is completely qualified, and the qualified rate is 100%.

Comparative example 1

An aluminum alloy ingot was prepared according to the method of example 1, except that:

in the burdening process, Al99.70 percent of Al ingot is used, Ti is added in the burdening process, and the Ti is blended according to the content of 0.02wt percent;

the refiner was added using Al-3Ti-0.15C alone at 3.5kg/t of molten metal.

The components of the aluminum alloy ingots prepared in comparative example 1 of the present invention were measured according to the method of example 1 of the present invention, and the results are shown in table 11:

TABLE 11 composition of high-Strength aluminum alloy ingots produced in comparative example 1 of the present invention

The fracture of the aluminum alloy ingot prepared by the method of comparative example 1 is detected according to the method of example 1, and the detection results are shown in fig. 1 (fracture SEM picture) and fig. 3 (fracture metallographic structure diagram), which shows that the fracture of the aluminum alloy ingot prepared by the method provided by comparative example 1 contains a large amount of Ti-containing particles, and the fracture yield of the alloy is greatly influenced; the loose size is large, the quantity is large, the subsequent processing deformation is not easy to weld, and the flaw detection and fracture qualification rate of the alloy cast ingot are greatly influenced.

As can be seen from the figures 1 to 4, the aluminum alloy cast ingot prepared by the method provided by the embodiment of the invention has small loose size, small quantity and clear and clean fracture, and the flaw detection and fracture yield of the aluminum alloy cast ingot are greatly improved.

According to the invention, the addition of a stokehole Al-Ti intermediate alloy is cancelled, an aluminum ingot with low impurity content is selected, the Fe + Si content is controlled to be less than or equal to 0.10%, the hydrogen content of the melt is controlled to be less than or equal to 0.08ml/100g.Al, Al-Ti-B and Al-Ti-C combined refining is adopted, and the production cost is reduced while the qualified rate of an oxide film at a fracture of the ingot is improved by cancelling the addition of the stokehole Al-Ti intermediate alloy; the impurity content of Fe and Si is controlled, the geometric waste generated by alloy ingot production can be used for producing other alloys, the use efficiency of the geometric waste is improved, and the flaw detection qualification rate of the ingot can be improved; the hydrogen content of the melt is controlled, the loosening size of the cast ingot can be greatly reduced, and the qualification rate of the oxide film at the fracture of the cast ingot and the qualification rate of flaw detection are improved. The preparation method provided by the invention can stably control the qualification rate of flaw detection of the cast ingot and the oxide film at the fracture over 98 percent.

While only the preferred embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.