A method of casting a 4032 aluminum alloy

Abstract

The present application relates to the field of metal, and particularly relates to a 4032 aluminum alloy melting and casting method. The 4032 aluminum alloy melting and casting method provided by the present application comprises the following processes: batching, pre-melting, overheating treatment + electromagnetic auxiliary, cooling treatment, stirring refining, sampling, refining standing and casting. Through the control of the above processes, especially by using melt overheating treatment + low-frequency electromagnetic auxiliary stirring, the original silicon phase and the corresponding high-silicon content cluster characteristics are eliminated, and a homogeneous and pure melt is obtained in combination with gas protection; in combination with a rapid cooling method, the melt is adjusted to a lower temperature state, and then through a post-adapted casting process, an ingot without coarse silicon phase is obtained, which is superior to the ingot microstructure obtained by a conventional modification agent treatment method, solves the problems of easy air absorption, unstable silicon phase control and easy performance deterioration caused by the conventional modification method, and is pollution-free to the environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of metal, in particular to a melting and casting method of 4032 aluminum alloy. BACKGROUND

[0002] 4032 is a eutectic aluminum alloy, which is currently used to manufacture dynamic and static plates of new energy vehicles. Coarse silicon phase is easily formed in 4032 ingot, which adversely affects the processing and service performance of subsequent products. The silicon phase in 4032 aluminum alloy used for dynamic and static plates of new energy vehicles is not greater than 0.03mm, while the existing industry standard of 4032 ingot stipulates that the maximum size of silicon phase is not more than 0.08mm, which cannot meet the control requirements of silicon phase in the existing application scenarios.

[0003] In order to solve the above problems, relevant researches show that the silicon phase size can be refined by modification agent optimization, multi-pass deformation, rapid solidification and other processes, but the effect is not ideal, and the silicon phase cannot be effectively controlled below 0.3mm. Moreover, the above methods cannot completely and stably control the silicon phase, or cannot realize engineering application, so it is urgent to develop a melting and casting method which can efficiently and stably control the silicon phase in industrialization. SUMMARY

[0004] Therefore, the present application provides a melting and casting method of 4032 aluminum alloy. The method provided by the present application can efficiently and stably control the silicon phase in 4032 aluminum alloy in industrialization, and effectively solve the problem that coarse silicon phase is easily formed in 4032 aluminum alloy.

[0005] The present application provides a melting and casting method of 4032 aluminum alloy, which comprises the following steps:

[0006] (A) batching:

[0007] The raw materials are batched according to the target alloy composition;

[0008] The composition of the target alloy is as follows in terms of mass percentage:

[0009] Si: 11%~13.5%;

[0010] Ni: 0.5%~1.3%;

[0011] Cu: 0.5%~1.3%;

[0012] Mg: 0.8%~1.3%;

[0013] The balance is Al and unavoidable impurities;

[0014] The raw materials include aluminum ingot, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, copper and magnesium;

[0015] (B) pre-melting:

[0016] putting aluminum-silicon intermediate alloy and part of aluminum ingot into a smelting furnace and heating pre-melting;

[0017] wherein the part of aluminum ingot accounts for 70% to 85% of the total aluminum ingot mass;

[0018] (C) overheating treatment and electromagnetic assistance:

[0019] after the alloy in step (B) is melted, protective gas is introduced into the smelting until the amount of protective gas reaches 8 to 10 m 3 , the melt is heated to 850 to 950℃, electromagnetic stirring is started, and the melt is stirred for a certain time;

[0020] (D) cooling treatment:

[0021] the remaining aluminum ingot, copper, magnesium and aluminum-nickel intermediate alloy are put into the smelting furnace, and the temperature is controlled at 740 to 760℃;

[0022] (E) stirring refining:

[0023] a refining agent is added into the smelting furnace for refining treatment, and electromagnetic stirring is started at the same time, and after the refining is completed, the surface dross is removed;

[0024] (F) refining and standing:

[0025] the melt obtained in step (E) is transferred to a holding furnace, the temperature is controlled at 740 to 770℃, a refining agent is added to refine the melt, and electromagnetic stirring is started at the same time, and after the refining is completed, the surface dross is removed and the melt is allowed to stand;

[0026] (G) casting:

[0027] the melt obtained in step F) is cast to obtain 4032 aluminum alloy ingot.

[0028] Preferably, in step (B), the temperature of the heating pre-melting is 740 to 760℃.

[0029] Preferably, in step (C), the electromagnetic frequency of the electromagnetic stirring is 5 to 20 Hz, and the time of the holding and stirring is 20 to 40 min.

[0030] Preferably, in step (C), the protective gas is nitrogen.

[0031] Preferably, in step (E), the electromagnetic frequency of the electromagnetic stirring is 0.7 to 4 Hz, and the time of the refining is 15 to 30 min.

[0032] Preferably, in step (E), the refining agent is MK4357B, and the amount used is 0.8 to 1.2 kg / t of aluminum.

[0033] Preferably, after the surface scum is removed after the refining is completed, step (E) further comprises: sampling analysis.

[0034] The sampling analysis comprises: sampling in the melt, detecting the chemical composition of the alloy, if the requirements are met, then entering the next process, if the requirements are not met, then diluting or supplementing.

[0035] Preferably, in step (F), the electromagnetic frequency of the electromagnetic stirring is 0.7-4 Hz; the refining time is 15-30 min; and the standing time is 20-50 min.

[0036] Preferably, in step (F), the refining agent is MK4357B, and the amount is 0.8-1.2 kg / t of aluminum.

[0037] Preferably, in step (G), the casting starting temperature is 730-760℃, the casting speed is 40-65 mm / min, and the water flow is 180-270 m 3 / h.

[0038] Beneficial effects: In view of the problem that the silicon phase of the existing 4032 ingot does not meet the requirement of less than 0.03 mm, the present application provides a melting and casting method of 4032 aluminum alloy, comprising the following processes: batching-premelting-overheating treatment+electromagnetic auxiliary-cooling treatment-stirring refining-sampling-refining standing-casting. Through the control of the above processes, especially by using melt overheating treatment+low-frequency electromagnetic auxiliary stirring, the original silicon phase and the corresponding high-silicon content cluster characteristics are eliminated, and a homogeneous and pure melt is obtained in combination with gas protection; in combination with a rapid cooling method, the melt is adjusted to a lower temperature state, and then a casting ingot without coarse silicon phase is obtained through a suitable casting process, which is superior to the casting ingot microstructure obtained by the conventional modification agent treatment method, solves the problems of easy air absorption, unstable silicon phase control, and easy performance deterioration caused by the conventional modification method, and does not pollute the environment. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0040] Fig. 1 the microstructure diagram of the 4032 aluminum alloy ingot obtained in Example 1;

[0041] Fig. 2 the microstructure diagram of the 4032 aluminum alloy ingot obtained in Comparative Example 1;

[0042] Fig. 3 Microstructure of the 4032 aluminum alloy ingot obtained in Comparative Example 2. DETAILED DESCRIPTION

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application.

[0044] Herein, in the technical features described in an open-ended manner, both a closed technical solution consisting of listed features and an open technical solution containing listed features are included.

[0045] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0046] Herein, in relation to numerical intervals, unless otherwise specified, the numerical intervals are considered to be continuous, and include the minimum and maximum values of the range, as well as every value between the minimum and maximum values. Further, when the range is referred to as an integer, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe a feature or a characteristic, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed herein are to be understood as including any and all sub-ranges subsumed therein.

[0047] Herein, in relation to data ranges, if only the unit is provided after the right end point, it means that the units of the left end point and the right end point are the same. For example, 850~950℃ means that the units of the left end point "850" and the right end point "950" are both ℃.

[0048] The present application provides a melting and casting method of a 4032 aluminum alloy, comprising the following steps:

[0049] (A) batching:

[0050] The raw materials are batched according to the target alloy composition;

[0051] The composition of the target alloy is as follows in terms of mass percentage:

[0052] Si: 11%~13.5%;

[0053] Ni: 0.5%~1.3%;

[0054] Cu: 0.5%~1.3%;

[0055] Mg: 0.8%~1.3%;

[0056] The balance is Al and unavoidable impurities;

[0057] The raw materials include: aluminum ingot, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, copper and magnesium;

[0058] (B) Pre-melting:

[0059] Put the aluminum silicon intermediate and part of the aluminum ingot into the smelting furnace and heat for pre-melting;

[0060] The part of the aluminum ingot accounts for 70% to 85% of the total mass of the aluminum ingot;

[0061] (C) Overheating treatment and electromagnetic assistance:

[0062] After the alloy in step (B) is melted, protective gas is introduced into the smelting furnace until the amount of protective gas reaches 8 to 10 m 3 When the temperature of the melt is raised to 850 to 950℃, electromagnetic stirring is started and the stirring is maintained for a certain time;

[0063] (D) Cooling treatment:

[0064] Put the remaining aluminum ingot, copper, magnesium and aluminum nickel intermediate alloy into the smelting furnace and control the temperature at 740 to 760℃;

[0065] (E) Stirring refining:

[0066] Add a refining agent to the smelting furnace for refining treatment, and start electromagnetic stirring at the same time. After the refining is completed, the surface dross is removed;

[0067] (F) Refining and standing:

[0068] Transfer the melt obtained in step (E) to a holding furnace, control the temperature at 740 to 770℃, add a refining agent to the melt for refining, and start electromagnetic stirring at the same time. After the refining is completed, the surface dross is removed and the melt is allowed to stand;

[0069] (G) Casting:

[0070] Casting the melt obtained in step (F) to obtain a 4032 aluminum alloy ingot.

[0071] In step (A),

[0072] The content of Si (silicon) can be specifically 11.0%, 11.1%, 11.2%, 11.3%, 11.4%, 11.5%, 11.6%, 11.7%, 11.8%, 11.9%, 12.0%, 12.1%, 12.2%, 12.3%, 12.4%, 12.5%, 12.6%, 12.7%, 12.8%, 12.9%, 13.0%, 13.1%, 13.2%, 13.3%, 13.4%, 13.5%.

[0073] The content of Ni (nickel) can be specifically 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%.

[0074] The content of Cu (copper) can be specifically 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%.

[0075] The content of Mg (magnesium) can be specifically 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%.

[0076] The balance is Al and inevitable impurities.

[0077] In some embodiments of the present application, the alloy composition is as follows: Si 11.8%, Ni 0.8%, Cu 0.9%, Mg 1.1%, the balance being Al and inevitable impurities.

[0078] In the present application, the raw materials used include: aluminum ingot, aluminum-silicon intermediate alloy, aluminum-nickel intermediate alloy, copper and magnesium. The present application does not have special restrictions on the way of batching, and can be carried out according to conventional means in the art, for example, calculating the proportion of each raw material according to the target composition, and weighing the corresponding amount of raw material for standby.

[0079] In the present application, the aluminum ingot is added twice, and a part is added in step (B), and the remaining part is added in the subsequent step. In the present application, the part of the aluminum ingot in step B) accounts for 70%~85% of the total mass of the aluminum ingot, and can be specifically 70%, 75%, 80%, 85%.

[0080] In the present application, the temperature of the heating pre-melting is preferably 740~760℃, and can be specifically 740℃, 745℃, 750℃, 755℃, 760℃.

[0081] In the present application, after the alloy in step (B) is melted, a protective gas is introduced into the smelting furnace. The type of the protective gas is not particularly limited, and can be a conventional protective gas in the art, such as nitrogen, argon, etc. The protective gas is introduced until the amount of the protective gas reaches 8~10m 3 , and can be specifically 8m 3 , 9m 3 , 10m 3When the amount of the protective gas reaches the target, the melt is heated to 850-950℃, specifically 850℃, 860℃, 870℃, 880℃, 890℃, 900℃, 910℃, 920℃, 930℃, 940℃, 950℃. After the melt reaches the temperature, the electromagnetic stirring is started while the melt is kept at the temperature for a certain time. In the present application, the electromagnetic frequency of the electromagnetic stirring is preferably 5-20Hz, specifically 5Hz, 10Hz, 15Hz, 20Hz. The holding time and the stirring time are the same, and the time of the holding and stirring is preferably 20-40min, specifically 20min, 25min, 30min, 35min, 40min.

[0082] In the present application, after step (C) is completed, the cold charge (i.e. the remaining aluminum ingot, pure copper, pure magnesium and aluminum-nickel intermediate alloy) is put into the smelting furnace, the cold charge is melted to take away heat to achieve cooling, and the temperature is controlled at 740-760℃ in the present application, specifically 740℃, 745℃, 750℃, 755℃, 760℃.

[0083] After the temperature is reduced to the target temperature in step (D), a refining agent is added to the smelting furnace for refining treatment. In the present application, the refining agent is preferably MK4357B. The amount of the refining agent is preferably 0.8-1.2kg / t of aluminum, specifically 0.8kg / t of aluminum, 0.9kg / t of aluminum, 1.0kg / t of aluminum, 1.1kg / t of aluminum, 1.2kg / t of aluminum.

[0084] The electromagnetic stirring is started while the refining agent is added for refining, i.e. the refining is accompanied by electromagnetic stirring. The electromagnetic frequency of the electromagnetic stirring is preferably 0.7-4Hz, specifically 0.7Hz, 1.0Hz, 1.2Hz, 1.5Hz, 2.0Hz, 2.5Hz, 3.0Hz, 3.5Hz, 4.0Hz. The time of the refining is preferably 15-30min, specifically 15min, 20min, 25min, 30min. After the refining is completed, the surface dross is removed.

[0085] In the present application, after step (E) is completed, sampling analysis is preferably performed, specifically, sampling is performed on the melt to detect the chemical composition of the alloy, and if the requirements are met, the process is transferred to the next step, and if the requirements are not met, dilution or material supplement is performed.

[0086] In the present application, after step (E) is completed, the obtained melt is transferred to a holding furnace, and the temperature is controlled at 740-770℃, specifically 740℃, 745℃, 750℃, 755℃, 760℃, 765℃, 770℃.

[0087] In the present application, the control is at the above-mentioned temperature, and a refining agent is added for refining. The refining agent is preferably MK4357B. The amount of the refining agent is preferably 0.8-1.2 kg / t of aluminum, and specifically can be 0.8 kg / t of aluminum, 0.9 kg / t of aluminum, 1.0 kg / t of aluminum, 1.1 kg / t of aluminum, 1.2 kg / t of aluminum.

[0088] In the present application, the refining agent is added for refining while the electromagnetic stirring is started, that is, the refining process is accompanied by electromagnetic stirring. The electromagnetic frequency of the electromagnetic stirring is preferably 0.7-4 Hz, and specifically can be 0.7 Hz, 1.0 Hz, 1.2 Hz, 1.5 Hz, 2.0 Hz, 2.5 Hz, 3.0 Hz, 3.5 Hz, 4.0 Hz. The time of the refining is preferably 15-30 min, and specifically can be 15 min, 20 min, 25 min, 30 min. After the refining is completed, the surface dross is removed, and the static setting is performed. The time of the static setting is preferably 20-50 min, and specifically can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min.

[0089] In the present application, the starting temperature of the casting is preferably 730-760℃, and specifically can be 730℃, 735℃, 740℃, 745℃, 750℃, 755℃, 760℃. The speed of the casting is preferably 40-65 mm / min, and specifically can be 40 mm / min, 45 mm / min, 50 mm / min, 55 mm / min, 60 mm / min, 65 mm / min. The water flow of the casting is preferably 180-270 m 3 / h, and specifically can be 180 m 3 / h, 190 m 3 / h, 200 m 3 / h, 210 m 3 / h, 220 m 3 / h, 230 m 3 / h, 240 m 3 / h, 250 m 3 / h, 260 m 3 / h, 270 m 3 / h. After the casting, the 4032 aluminum alloy ingot is obtained.

[0090] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present application, and are not limitations on the claims of the present application.

[0091] Example 1

[0092] (A) Ingredients:

[0093] The target alloy composition is: Si 11.8%, Ni 0.8%, Cu 0.9%, Mg 1.1%, the balance being Al and inevitable impurities. Pure aluminum ingots, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, pure copper and pure magnesium are weighed according to the above target alloy composition.

[0094] (B) Pre-melting:

[0095] The aluminum silicon intermediate alloy and 80% pure aluminum ingots are put into the smelting furnace and heated to 740°C for pre-melting.

[0096] (C) Overheating treatment and electromagnetic assistance:

[0097] After the alloy in step (B) is melted, nitrogen protection is introduced into the smelting furnace until the nitrogen gas amount reaches 9 m 3 L, the melt is heated to 880°C, and after reaching this temperature, the temperature is kept constant while the electromagnetic stirring is started, the electromagnetic frequency is set to 10 HZ, and the temperature is kept constant for 30 min.

[0098] (D) Cooling treatment:

[0099] The remaining 20% pure aluminum ingots are put into the furnace, and then pure copper, pure magnesium and aluminum nickel intermediate alloy are put into the furnace, and the temperature is controlled at 755°C.

[0100] (E) Stirring refining:

[0101] Refining agent MK4357B (0.8 kg / t aluminum) is added to the smelting furnace for refining treatment, and at the same time, electromagnetic stirring is started, the electromagnetic frequency is set to 1.2 HZ, and the stirring refining is carried out for 25 min. After refining, the surface dross is removed.

[0102] The melt is sampled and the chemical composition of the alloy is detected. If it meets the requirements, it is transferred to the next process. If it does not meet the requirements, it is diluted or supplemented.

[0103] (F) Refining and standing:

[0104] The melt obtained in step (E) is transferred to a holding furnace, the temperature is controlled at 755°C, and refining agent MK4357B (0.8 kg / t aluminum) is added to the melt for refining. At the same time, electromagnetic stirring is started, the electromagnetic frequency is set to 1.2 HZ, and the stirring refining is carried out for 20 min. After refining, the surface dross is removed, and the melt is kept standing for 40 min.

[0105] (G) Casting:

[0106] The melt obtained in step (F) is cast, the casting temperature is controlled at 745°C, the casting speed is 50 mm / min, the water flow is 210 m 3 / h, and after casting, 4032 aluminum alloy ingots are obtained.

[0107] Example 2

[0108] (A) Batch:

[0109] The target alloy composition is: Si 11.8%, Ni 0.8%, Cu 0.9%, Mg 1.1%, the balance being Al and inevitable impurities. Pure aluminum ingots, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, pure copper and pure magnesium are weighed according to the above target alloy composition.

[0110] (B) Pre-melting:

[0111] The aluminum silicon intermediate alloy and 75% pure aluminum ingots are put into the smelting furnace and heated to 760°C for pre-melting.

[0112] (C) Superheating treatment and electromagnetic assistance:

[0113] After the alloy in step (B) is melted, nitrogen protection is introduced into the smelting furnace until the nitrogen gas amount reaches 9 m 3 The melt is heated to 920°C, and after reaching this temperature, the temperature is kept constant while the electromagnetic stirring is turned on, the electromagnetic frequency is set to 15 HZ, and the temperature is kept constant for 30 min.

[0114] (D) Cooling treatment:

[0115] The remaining 25% pure aluminum ingots are put into the furnace, and then pure copper, pure magnesium and aluminum nickel intermediate alloy are put into the furnace, and the temperature is controlled at 755°C.

[0116] (E) Stirring refining:

[0117] Refining agent MK4357B (1.2 kg / t of aluminum) is added to the smelting furnace for refining treatment, and at the same time, electromagnetic stirring is turned on, the electromagnetic frequency is set to 1.2 HZ, and the stirring refining is carried out for 25 min. After refining, the surface dross is removed.

[0118] The melt is sampled to detect the chemical composition of the alloy. If it meets the requirements, it is transferred to the next process. If it does not meet the requirements, it is diluted or supplemented.

[0119] (F) Refining and standing:

[0120] The melt obtained in step (E) is transferred to a holding furnace, the temperature is controlled at 750°C, and refining agent MK4357B (1.2 kg / t of aluminum) is added to the melt for refining. At the same time, electromagnetic stirring is turned on, the electromagnetic frequency is set to 1.2 HZ, and the stirring refining is carried out for 25 min. After refining, the surface dross is removed, and the melt is kept standing for 30 min.

[0121] (G) Casting:

[0122] The melt obtained in step (F) is cast, the casting temperature is controlled at 740°C, the casting speed is 45 mm / min, the water flow is 190 m 3 / h, and the casting is completed to obtain 4032 aluminum alloy ingot.

[0123] Comparative Example 1

[0124] (1) Ingredients:

[0125] The target alloy composition is: Si 11.8%, Ni 0.8%, Cu 0.9%, Mg 1.1%, and the balance is Al and inevitable impurities. Pure aluminum ingot, aluminum-silicon intermediate alloy, aluminum-nickel intermediate alloy, pure copper and pure magnesium are weighed according to the above target alloy composition.

[0126] (2) The pure aluminum ingot, pure copper, pure magnesium, aluminum-silicon intermediate alloy and aluminum-nickel intermediate alloy are put into the smelting furnace, heated to 740°C for pre-melting.

[0127] (3) After the alloy in step (2) is melted, the temperature is controlled at 755°C, the refining agent MK4357B (the amount is 0.8 kg / t of aluminum) is added for refining treatment, and the electromagnetic stirring is started at the same time, the electromagnetic frequency is set to 1.2HZ, and the stirring refining is 25 min. After refining, the surface dross is removed.

[0128] The melt is sampled and the chemical composition of the alloy is detected. If it meets the requirements, it will be transferred to the next process. If it does not meet the requirements, it will be diluted or supplemented.

[0129] (4) The melt obtained in step (3) is transferred to the holding furnace, the temperature is controlled at 755°C, the aluminum strontium alloy is added for modification treatment, and the strontium content is controlled at 0.03%; the refining agent MK4357B (the amount is 0.8 kg / t of aluminum) is added for refining the melt, and the electromagnetic stirring is started at the same time, the electromagnetic frequency is set to 1.2HZ, and the stirring refining is 20 min. After refining, the surface dross is removed, and the melt is left to stand for 40 min.

[0130] (5) Casting: The melt obtained in step (4) is cast, the casting temperature is controlled at 745°C, the casting speed is 50 mm / min, the water flow is 210 m 3 / h, and the casting is completed to obtain 4032 aluminum alloy ingot.

[0131] Comparative Example 2

[0132] (A) Ingredients:

[0133] The target alloy composition is: Si 11.8%, Ni 0.8%, Cu 0.9%, Mg 1.1%, the balance being Al and inevitable impurities. Pure aluminum ingot, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, pure copper and pure magnesium are weighed according to the above target alloy composition.

[0134] (B) Pre-melting:

[0135] The aluminum silicon intermediate alloy and 80% pure aluminum ingot are put into the smelting furnace and heated to 740°C for pre-melting.

[0136] (C) Overheating treatment:

[0137] After the alloy in step (B) is melted, nitrogen protection is introduced into the smelting furnace until the nitrogen gas amount reaches 9m 3 L, the melt is heated to 880°C and kept for 30 min.

[0138] (D) Cooling treatment:

[0139] The remaining 20% pure aluminum ingot is put into the furnace, and then pure copper, pure magnesium and aluminum nickel intermediate alloy are put into the furnace, and the temperature is controlled at 755°C.

[0140] (E) Stirring refining:

[0141] Refining agent MK4357B (0.8 kg / t of aluminum) is added to the smelting furnace for refining treatment, and the electromagnetic stirring is started at the same time, the electromagnetic frequency is set to 1.2HZ, and the stirring refining is carried out for 25 min. After refining, the surface dross is removed.

[0142] The melt is sampled and the chemical composition of the alloy is detected. If it meets the requirements, it will be transferred to the next process. If it does not meet the requirements, it will be diluted or supplemented.

[0143] (F) Refining and standing:

[0144] The melt obtained in step (E) is transferred to the holding furnace, the temperature is controlled at 755°C, and refining agent MK4357B (0.8 kg / t of aluminum) is added to the melt for refining. At the same time, electromagnetic stirring is started, the electromagnetic frequency is set to 1.2HZ, and the stirring refining is carried out for 20 min. After refining, the surface dross is removed, and the melt is allowed to stand for 40 min.

[0145] (G) Casting:

[0146] The melt obtained in step (F) is cast, the casting temperature is controlled at 745°C, the casting speed is 50 mm / min, the water flow is 210m 3 / h, and the casting is completed to obtain 4032 aluminum alloy ingot.

[0147] The microstructures of the alloys obtained in Example 1, Comparative Example 1 and Comparative Example 2 are respectively asFigs. 1-3 As shown in FIG. 1, the silicon phase of the 4032 aluminum alloy ingot prepared by the method of the present application is controlled to be less than 0.03 mm. Fig. 1 As can be seen, the silicon phase of the 4032 aluminum alloy ingot prepared by the method of the present application is controlled to be less than 0.03 mm; and Figs. 2-3 As can be seen, the 4032 aluminum alloy ingots prepared by the conventional method of Comparative Example 1 and the method of Comparative Example 2 without increasing the low-frequency electromagnetic auxiliary stirring in the melt overheating treatment both have silicon phases greater than 0.03 mm. The melting and casting method of the 4032 aluminum alloy provided by the present application uses melt overheating treatment + low-frequency electromagnetic auxiliary stirring to eliminate the original silicon phase and the corresponding high-silicon content cluster characteristics, combined with gas protection, to obtain a homogeneous and pure melt; combined with a rapid cooling method, the melt is adjusted to a lower temperature state, and then through a post-adapted casting process, an ingot without coarse silicon phase is obtained.

[0148] The principles and implementations of the present application are described herein by applying specific examples, and the above description of the examples is only used to help understand the method of the present application and its core idea, including the best mode, and also enables any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application. The scope of protection of the present application is defined by the claims, and can include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the textual expression of the claims, or if they include equivalent structural elements that are not substantially different from the textual expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method of casting a 4032 aluminum alloy, characterized by, The method comprises the following steps: (A) batching: raw materials are batched according to target alloy composition; wherein the target alloy composition is as follows in terms of mass percentage: Si: 11%~13.5%; Ni: 0.5%~1.3%; Cu: 0.5%~1.3%; Mg: 0.8%~1.3%; balance: Al and inevitable impurities; the raw materials comprise aluminum ingots, aluminum silicon intermediate alloy, aluminum nickel intermediate alloy, copper and magnesium; (B) pre-melting: aluminum silicon intermediate alloy and part of aluminum ingots are put into a smelting furnace for heating pre-melting; wherein the part of aluminum ingots accounts for 70%~85% of the total mass of aluminum ingots; the temperature for the heating pre-melting is 740~760℃; (C) superheating treatment and electromagnetic assistance: After the alloy in step (B) is melted, protective gas is introduced into the smelting furnace until the amount of protective gas reaches 8-10 m 3 When the melt is heated to 850-950℃, electromagnetic stirring is started, and the melt is stirred for a certain time; the electromagnetic frequency of the electromagnetic stirring is 5-20 Hz; the time of the heat preservation and stirring is 20-40 min. (D) cooling treatment: the remaining aluminum ingots, copper, magnesium and aluminum nickel intermediate alloy are put into the smelting furnace, and the temperature is controlled at 740~760℃; (E) refining: a refining agent is added to the smelting furnace for refining treatment, and electromagnetic stirring is started at the same time, and after the refining is completed, surface dross is removed; (F) refining and standing: the melt obtained in step (E) is transferred to a holding furnace, the temperature is controlled at 740~770℃, no modification treatment is performed, a refining agent is directly added to the melt for refining, electromagnetic stirring is started at the same time, surface dross is removed after the refining is completed, and standing is performed; the refining agent is MK4357B, and the amount is 0.8~1.2kg / t of aluminum; the electromagnetic frequency of the electromagnetic stirring is 0.7~4Hz; (G) casting: the melt obtained in step (F) is cast to obtain 4032 aluminum alloy ingot; the casting start temperature is 730~760℃.

2. The casting method according to claim 1, characterized in that, In step (C), the protective gas is nitrogen.

3. The casting method according to claim 1, characterized by, In step (E), the electromagnetic frequency of the electromagnetic stirring is 0.7~4Hz; and the refining time is 15~30min.

4. The casting method according to claim 1, characterized by, In step (E), the refining agent is MK4357B, and the amount is 0.8~1.2kg / t of aluminum.

5. The casting method according to claim 1, characterized by, In step (E), after the surface dross is removed after the refining is completed, it further comprises sampling analysis; the sampling analysis comprises sampling in the melt, detecting alloy chemical composition, if the requirements are met, then the next process is entered, if the requirements are not met, then dilution or material supplement is performed.

6. The casting method according to claim 1, characterized by In step (F), the refining time is 15~30min; and the standing time is 20~50min.

7. The casting method according to claim 1, characterized by, In step (G), the casting speed is 40 to 65 mm / min, and the water flow rate is 180 to 270 m 3 / h.

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