CN113337753B - Method for preparing B-level copper ingot through horizontal continuous casting - Google Patents

Abstract

The invention discloses a method for preparing a B-level copper ingot by horizontal continuous casting, which is characterized by comprising the following steps of: the preparation method comprises the following preparation steps: 1) Preparing materials: preparing raw materials according to required components, wherein the raw materials comprise: an electrolytic plate, 59-1 iron powder, 0# zinc, 1# lead, an aluminum block, a magnesium block, an aluminum boron alloy, a refining agent, a deslagging agent, borax and a refining agent; 2) Smelting: (1) adding an electrolytic plate for melting; (2) After the electrolytic plate is melted, 59-1 iron powder removal and borax mixing are added into a smelting furnace, and the mixture is pressed to 550-650V. After the copper ingot is polished, the thickness is 100mm ² On the regional area, the quantity of hard spot and gas pocket is within 5, and the grade reaches B level spindle standard, satisfies production environmental protection copper ingot for the sanitary bath operation requirement, shortens the process moreover, and continuity of operation has higher profit margin, and market competition advantage is strong.

Description

A method for preparing B-grade copper ingots by horizontal continuous casting

technical field

The invention belongs to the technical field of copper alloys, in particular to a method for preparing B-grade copper ingots by horizontal continuous casting.

Background technique

Lead brass has excellent machinability, good cold and hot casting performance, easy cutting, and the surface of the processed workpiece is smooth. It is widely used in electronic telecommunications, home appliances, aviation, hardware accessories and sanitary plumbing products, especially in sanitary products for home decoration. The amount of use is very large. With the advancement of my country's urbanization process and the rapid development of the real estate market, my country's sanitary ware market has also developed rapidly. The current bathroom products are mainly plumbing components, valves, showers and so on. The raw materials of copper ingots commonly used in sanitary ware in my country are red copper, zinc, lead, silicon, aluminum, processed materials, etc. The production process is mainly gravity casting. 2. The operation is convenient, the gravity flow is used to enter the mold, and the molding is naturally cooled. Therefore, gravity casting is suitable for B-grade copper ingots with lower requirements for impurities, but this method has problems such as high cost, low efficiency, inability to produce continuously, and long process flow.

B-grade copper ingots are mainly used for plumbing parts such as bathrooms and valves. The conventional production process is smelting-gravity casting-trimming-polishing-inspection-packing-warehousing. The process is long and requires refilling and mold cleaning after casting. If the horizontal continuous casting process is used to produce B-grade copper ingots, the casting, trimming, polishing, mold cleaning, and spraying of release agents can all be omitted in terms of operation, the working environment can be greatly improved, the efficiency can be greatly improved, and the cost is significant. However, because the horizontal continuous casting does not have an open space for the impurities to float up, if the impurities are not completely removed during the smelting process, the impurities will be caught in the grain boundary area and the dendrite intersection area, and it is difficult to exclude them from the surface of the ingot. Finally, the number of polished hard spots is large, which cannot meet the requirements of B-grade copper ingots.

Therefore, the method for preparing B-grade copper ingots by horizontal continuous casting still needs further improvement.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing B-grade copper ingots by horizontal continuous casting that meets the requirements of B-grade copper ingots.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: a method for preparing B-grade copper ingots by horizontal continuous casting, which is characterized in that it includes the following preparation steps:

1) Raw material preparation: Prepare raw materials according to the required ingredients, including: electrolytic plate, 59-1 iron removal powder, 0# zinc, 1# lead, aluminum block, magnesium block, aluminum boron alloy, refining agent, slag remover, borax , refiner;

2) Melting:

(1) add electrolytic plate to melt;

(2) After the electrolytic plate is melted, add 59-1 iron powder and borax into the smelting furnace, and press it to 550-650V. 1100℃～1150℃, after adding the slag remover, start to quickly remove the slag, after the slag removal is completed, the voltage is turned to 550～650V, and the temperature is reduced to 950℃～1000℃;

(3) After the 59-1 iron powder is completely melted, the voltage is reduced to 450~540V, the temperature is lowered to 900°C~950°C, and aluminum block, 1# lead, and 0# zinc are added in sequence; among them, the aluminum block is at this stage join all;

(4) Assay feeding, after the composition is qualified, the voltage is raised to 750-850V, the fire is blown for 3-10 seconds, the voltage is reduced to 550-650V, and the temperature is 1000-1100°C;

(5) The copper water is transferred to the holding furnace, and the refining agent is pressed into the copper water with a bell jar, and taken out after the reaction is completed;

(6) Add magnesium block and aluminum-boron alloy respectively, and fully stir;

(7) Use a bell jar to press in the refiner and stir for 20-40 seconds;

(8) When the voltage reaches 750-850V, the temperature rises and bursts into flames for 3-10 seconds, the voltage drops to 350-450V, the temperature drops to 950-1000°C, and the holding furnace stands still for 5-15 minutes;

(9) When the voltage reaches 550-650V, the throwing cup is qualified and the temperature reaches 1050°C-1070°C for drawing casting. If it is unqualified, continue refining until it is qualified;

3) Drawing casting: After the temperature is qualified, the copper water flows into the crystallizer and starts drawing and casting to obtain copper ingots. The casting speed is 1-10mm/min, the pitch is 3-10mm, and the pause is 1-3s;

The mass percent composition of the copper ingot is: Cu: 59%-60%, Al: 0.5%-0.8%, Sn+Fe≤1.0%, As≤0.02%, Pb: 1.0%-1.8%, Si≤0.02% , Ni ≤ 0.2%, Mn ≤ 0.02%, Bi ≤ 0.02%, the balance is Zn, and other impurities are within 0.01%.

Preferably, the added amount of borax is 0.01-0.03% of the total mass of raw materials, the added amount of magnesium block is 0.001-0.003% of the total mass of raw materials, and the added amount of aluminum-boron alloy is 0.005-0.015% of the total mass of raw materials. Magnesium blocks are mainly used for degassing and oxidizing slag inclusions. Magnesium forms magnesium oxide and impurity oxides form impurity salts, and finally floats on the surface of the melt. The addition of magnesium is higher than 0.003%, which will increase the brittleness of the material and does not use the balance of hydrogen and oxygen. , leading to the formation of pores due to hydrogen evolution, and it has basically no effect below 0.001%.

Both aluminum-boron alloy and borax act on grain refinement, aluminum boron, borax ionizes boron after melting, boron can be used as crystallization core, heterogeneous nucleation, grain refinement, aluminum-boron alloy higher than 0.015% will increase copper water If the viscosity is lower than 0.005%, the effect is weak. If the borax is higher than 0.03%, the furnace ash will be compacted, resulting in increased mechanical slag inclusion in the furnace ash.

As a preference, in the step 3), primary cooling water is added to the outer copper sleeve of the crystallizer, and secondary cooling water is set at a distance of 30 mm to 80 mm from the billet exiting the crystallizer; the water temperature of the primary cooling water is 10°C to 30°C, The flow rate of the cooling water is 2-8m ³ /h, the water temperature of the secondary cooling water is 10°C-30°C, and the flow rate of the cooling water is 2-8m ³ /h. On the one hand, through the control of the cooling water twice, the grains of the ingot are further refined. The grain refinement can reduce the probability of impurities existing in the matrix, because the grain refinement eliminates the dendrite voids, and eliminates the inclusion of impurities in the dendrite voids. However, the possibility of reaching the surface of the ingot cannot be ruled out. After the grains are refined, the impurities will be squeezed out to the surface of the ingot along with the crystallization process.

Preferably, the microstructure of the copper ingot obtained in the step 3) is: both the edge region and the central region of the ingot are equiaxed grain regions, the grain size of the edge region is below 15 μm, and the grain size of the middle region is 50 μm the following.

The microstructure of the copper ingot obtained by traditional horizontal continuous casting is: the edge area of the ingot is an equiaxed grain area, the central area is an equiaxed grain area, the middle area between the edge area and the central area of the ingot is a columnar grain, and the edge area is an equiaxed grain area. The grain size of the area is relatively small, but the middle area is a coarse columnar grain, and the grain is coarse, which is easy to cause difficulty in impurity removal during the crystallization process. Coarse columnar crystals are eliminated in the copper ingot obtained in the present application, and there are no dendrite voids, and the crystal grains are refined, so that impurities are expelled to the surface of the casting rod along with the crystallization process, and the presence of impurities in the copper ingot is reduced.

Preferably, the specification of the copper ingot is Φ15-80 mm, the edge area is the area within 2-5 mm from the surface of the copper ingot, and the remaining area is the middle area.

As preferably, after the copper ingot obtained in the step 3) is polished, the total number of hard spots and pores in the area of 100 mm is within ⁵ .

Compared with the prior art, the present invention has the advantages of: the copper ingot is prepared by controlling the feeding sequence and process parameters of the horizontal continuous casting, the copper ingot product has good polishing quality, no meteor tail and concave and convex defects, and the surface of the finished product is smooth and meticulous. It is conducive to the later electroplating operation; after the copper ingot is polished, the number of hard spots and pores in the area of 100mm2 is within ⁵ , and the grade reaches the standard of Class B ingots, which meets the requirements for the production of copper ingots for environmental protection sanitary ware, and shortens the process , Continuous operation, higher profit margins, and strong market competitive advantages.

Description of drawings

Fig. 1 is the metallographic photograph (enlarged 200 times) of the embodiment of the present invention 1;

Fig. 2 is the metallographic photograph of comparative example 1 of the present invention (magnification 200 times).

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Example 1

Melting is carried out with a 2t horizontal continuous casting furnace.

The method for preparing B-grade copper ingots by horizontal continuous casting comprises the following preparation steps:

1) Raw material preparation: Prepare raw materials according to the required ingredients, including: electrolytic plate, 59-1 iron removal powder, 0# zinc, 1# lead, aluminum block, magnesium block, aluminum boron alloy, refining agent, slag remover, borax , refiner; a total of 1.5t;

2) Melting:

(1) add electrolytic plate to melt;

(2) After the electrolytic plate is melted, add 3kg of 59-1 iron removal powder and borax into the melting furnace, and press it to 600V. After the 59-1 iron removal powder is completely melted, apply a high voltage of 820V, and the temperature rises to 1100℃～ 1150°C, after adding the slag remover, start to quickly remove the slag. After the slag removal is completed, the voltage is raised to 600V, and the temperature drops to 950-1000°C;

(3) After the 59-1 iron powder is completely melted, the voltage is lowered to 500V, the temperature is lowered to 900-950°C, and the aluminum block, 1# lead, and 0# zinc are added in sequence; among them, all the aluminum blocks are added at this stage;

(4) Assay feeding, after the composition is qualified, the voltage is raised to 800V, the flame is blown for 5 seconds, the voltage is reduced to 600V, and the temperature is 1000-1100°C;

(5) The copper water is transferred to the holding furnace, and the refining agent is pressed into the copper water with a bell jar, and taken out after the reaction is completed;

(6) Add 450g magnesium block and 1.5kg aluminum-boron alloy respectively, and fully stir;

(7) Use a bell jar to press in the refiner and stir for 30 seconds;

(8) The voltage is raised to 800V, the temperature rises and bursts into flames for 5 seconds, the voltage drops to 400V, the temperature drops to 950°C, and the holding furnace stands still for 5 minutes;

(9) When the voltage reaches 600V, the throwing cup is qualified and the temperature reaches 1050 ℃ ~ 1070 ℃ for drawing casting. If it is unqualified, continue refining until it is qualified;

3) Drawing casting: After the temperature is qualified, the copper water flows into the crystallizer to start drawing and casting to obtain copper ingots. The casting specification is Φ55mm, the casting speed is 5mm/min, the pitch is 5mm, and the pause is 3s; cooling water is added once to the copper sleeve outside the mold. The secondary cooling water is set at a distance of 50mm from the billet exiting the crystallizer; the water temperature of the primary cooling water is 10°C to 30°C, the flow rate of the cooling water is 5m ³ /h, and the water temperature of the secondary cooling water is 10°C to 30°C. The flow rate of cooling water is 5m ³ /h.

Example 2

Melting is carried out with a 2t horizontal continuous casting furnace.

The method for preparing B-grade copper ingots by horizontal continuous casting comprises the following preparation steps:

1) Raw material preparation: Prepare raw materials according to the required ingredients, including: electrolytic plate, 59-1 iron removal powder, 0# zinc, 1# lead, aluminum block, magnesium block, aluminum boron alloy, refining agent, slag remover, borax , refiner; a total of 1.5t;

2) Melting:

(1) add electrolytic plate to melt;

(2) After the electrolytic plate is melted, mix 59-1 iron removal powder and 3.5kg borax into the melting furnace, and press it to 550V. After the 59-1 iron removal powder is completely melted, apply a high voltage of 850V, and the temperature rises to 1100°C ~1150°C, after adding the slag remover, start to quickly remove the slag. After the slag removal is completed, the voltage is raised to 600V, and the temperature drops to 950°C~1000°C;

(3) After the iron powder of 59-1 is completely melted, the voltage is lowered to 520V, the temperature is lowered to 900°C~950°C, and aluminum blocks, 1# lead, and 0# zinc are added in sequence; among them, all aluminum blocks are added at this stage ;

(4) Assay feeding, after the composition is qualified, the voltage is raised to 800V, the flame is blown for 5 seconds, the voltage is reduced to 600V, and the temperature is 1000-1100°C;

(5) The copper water is transferred to the holding furnace, and the refining agent is pressed into the copper water with a bell jar, and taken out after the reaction is completed;

(6) Add 400g magnesium block and 1.0kg aluminum-boron alloy respectively, and fully stir;

(7) Use a bell jar to press in the refiner and stir for 30 seconds;

(8) The voltage is raised to 750V, the temperature rises and bursts into flames for 5 seconds, the voltage is reduced to 400V, the temperature is reduced to 950-1000°C, and the holding furnace is static for 10 minutes;

(9) When the voltage reaches 600V, the throwing cup is qualified and the temperature reaches 1050 ℃ ~ 1070 ℃ for drawing casting. If it is unqualified, continue refining until it is qualified;

3) Drawing casting: After the temperature is qualified, the copper water flows into the crystallizer and starts drawing and casting to obtain copper ingots. The drawing casting specification is Φ60mm, the drawing casting speed is 3mm/min, the pitch is 5mm, and the pause is 2s; cooling water is added once to the copper sleeve outside the mold. Set secondary cooling water at a distance of 30mm from the billet outlet crystallizer; the water temperature of the primary cooling water is 10°C-30°C, the flow rate of the cooling water is 3m ³ /h, and the water temperature of the secondary cooling water is 10°C-30°C. The flow rate of cooling water is 5m ³ /h.

Example 3

The method for preparing B-grade copper ingots by horizontal continuous casting comprises the following preparation steps:

1) Raw material preparation: Prepare raw materials according to the required ingredients, including: electrolytic plate, 59-1 iron removal powder, 0# zinc, 1# lead, aluminum block, magnesium block, aluminum boron alloy, refining agent, slag remover, borax , refiner; a total of 1.5t;

2) Melting:

(1) add electrolytic plate to melt;

(2) After the electrolytic plate is melted, mix 59-1 iron powder and 2.5Kg borax into the melting furnace, and press it to 650V. After the 59-1 iron powder is completely melted, apply a high voltage of 750V, and the temperature rises to 1100°C ~1150°C, after adding the slag remover, start to quickly remove the slag. After the slag removal is completed, the voltage is raised to 600V, and the temperature drops to 950°C~1000°C;

(3) After the 59-1 iron powder is completely melted, the voltage is lowered to 470V, the temperature is lowered to 900°C~950°C, and aluminum blocks, 1# lead, and 0# zinc are added in sequence; among them, the aluminum blocks are all added at this stage ;

(4) Assay feeding, after the composition is qualified, the voltage is raised to 800V, the flame is blown for 10 seconds, the voltage is reduced to 600V, and the temperature is 1000-1100°C;

(5) The copper water is transferred to the holding furnace, and the refining agent is pressed into the copper water with a bell jar, and taken out after the reaction is completed;

(6) Add 400g magnesium block and 1.1kg aluminum-boron alloy respectively, and fully stir;

(7) Use a bell jar to press into the refiner and stir for 20 seconds;

(8) The voltage is raised to 800V, the temperature rises and bursts into flames, and lasts for 10 seconds, the voltage is reduced to 400V, the temperature is reduced to 950-1000°C, and the holding furnace is static for 15 minutes;

(9) When the voltage reaches 600V, the throwing cup is qualified and the temperature reaches 1050 ℃ ~ 1070 ℃ for drawing casting. If it is unqualified, continue refining until it is qualified;

3) Drawing casting: After the temperature is qualified, the copper water flows into the crystallizer to start drawing and casting to obtain copper ingots. The drawing casting specification is Φ20mm, the drawing casting speed is 4mm/min, the pitch is 10mm, and the pause is 1s; cooling water is added once to the copper sleeve outside the mold. The secondary cooling water is set at a distance of 60mm from the billet exiting the crystallizer; the water temperature of the primary cooling water is 10°C-30°C, the flow rate of the cooling water is 7m ³ /h, and the water temperature of the secondary cooling water is 10°C-30°C. The flow rate of cooling water is 4m ³ /h.

comparative example

Melting adopts 2t for gravity casting.

1. Raw materials: 1.5t ingredients

(1) Electrolytic plate, 59-1 iron powder, 0# zinc, 1# lead, aluminum block, magnesium block, aluminum boron alloy;

(2) Refining agent, deslagging agent, borax, refining agent.

2. Melting:

(1) add electrolytic plate to melt;

(2) After the electrolytic plate is melted, add 59-1 iron removal powder into the smelting furnace, raise the temperature, and set the voltage to 800V;

(3) After all the raw materials are melted, the slag is removed, and after the slag removal is completed, the voltage is lowered to 400V, the temperature is 1000°C to 950°C, and aluminum, lead, and zinc are added in sequence;

(4) Assay feeding, after the composition is qualified, the voltage is increased to 800V, and the voltage is lowered for about 5 seconds after the big fire, the voltage is lower than 600V, and the temperature is 1050 ° C to 1000 ° C;

(5) 7.5kg of refining agent is pressed into copper water with a bell furnace, and the reaction is completed and taken out;

(6) After the refining is completed, keep the temperature constant, add 450g of magnesium block and 1.5kg of aluminum-boron alloy respectively, and fully stir;

(7) Use a bell jar to press in 2.5kg of domestic refining agent, keep stirring for about 25 seconds, and stand still for 10 minutes;

(8) If the throwing cup is qualified and the temperature reaches the requirement (1050°C ~ 1070°C), cast it, and if it is unqualified, continue refining until it is qualified.

Take the central area of the copper ingot in Example 1 and observe its microstructure. It can be seen from Figure 1 that the grain size of the horizontal continuous casting is 30 μm, and the spheroidization trend of the grains is very obvious, which means that the copper ingot continuous casting It has a good impurity removal effect, and finally a microstructure with fine grains is obtained.

Take the central area of the copper ingot of the comparative example and observe its microstructure. It can be seen from Figure 2 that the grains of the B-grade ingot produced by casting are short rod-shaped and uniform in size.

B-level ingot inspection standard: select a small section of sample, polish, observe defects such as hard spots and pores in the area of ^100mm2 , and judge whether it meets the standard. If it is within 5 points, it is judged to be qualified, and if it is higher than 5 points, it is unqualified. It can be seen from Table 2 that the number of hard spots and pores in this embodiment is less than 5, and the quality is qualified.

The copper ingot composition (wt%) of table 1 embodiment of the present invention and comparative example

The microstructure of the embodiment of the present invention and comparative example of table 2

Claims (4)

1. A method for preparing a B-level copper ingot by horizontal continuous casting is characterized by comprising the following steps: the preparation method comprises the following preparation steps:

1) Preparing materials: preparing raw materials according to required components, wherein the raw materials comprise: an electrolytic plate, 59-1 iron powder, 0# zinc, 1# lead, an aluminum block, a magnesium block, an aluminum boron alloy, a refining agent, a deslagging agent, borax and a refining agent; the addition amount of the borax is 0.01-0.03% of the total mass of the raw materials, the addition amount of the magnesium blocks is 0.001-0.003% of the total mass of the raw materials, and the addition amount of the aluminum-boron alloy is 0.005-0.015% of the total mass of the raw materials;

2) Smelting:

(1) Adding an electrolytic plate for melting;

(2) After the electrolytic plate is melted, adding 59-1 iron powder removal mixture and borax into a smelting furnace, pressurizing to 550-650V, after the 59-1 iron powder removal mixture is completely melted, pressurizing to 750-850V, raising the temperature to 1100-1150 ℃, adding a deslagging agent, then rapidly dredging slag, after the slag is dredged, pressurizing to 550-650V, and reducing the temperature to 950-1000 ℃;

(3) After 59-1 iron powder is completely melted, reducing the voltage to 450-540V, reducing the temperature to 900-950 ℃, and sequentially adding an aluminum block, 1# lead and 0# zinc; wherein, the aluminum block is added in the stage;

(4) Testing and supplementing materials, after the components are qualified, increasing the voltage to 750-850V, carrying out large flame spraying for 3-10 seconds, and reducing the voltage to 550-650V at the temperature of 1000-1100 ℃;

(5) Transferring the molten copper into a holding furnace, pressing a refining agent into the molten copper by using a bell jar, and taking out after the reaction is finished;

(6) Respectively adding magnesium blocks and aluminum boron alloy, and fully stirring;

(7) Pressing the refiner in a bell jar, and stirring for 20-40 seconds;

(8) The voltage is increased to 750-850V, the temperature is increased to carry out large flame spraying for 3-10 seconds, the voltage is reduced to 350-450V, the temperature is reduced to 950-1000 ℃, and the holding furnace is kept still for 5-15 min;

(9) The voltage is increased to 550-650V, the throwing cup is qualified, the temperature reaches 1050-1070 ℃, the drawing casting is carried out, the unqualified cup is not qualified, and the refining is continued until the cup is qualified;

3) Drawing and casting: after the temperature is qualified, the copper water flows into a crystallizer to start casting to obtain a copper ingot, the casting speed is 1-10 mm/min, the pitch is 3-10 mm, and the time is 1-3 s; adding primary cooling water into a copper sleeve outside the crystallizer, and arranging secondary cooling water at a position 30-80 mm away from the bar billet out of the crystallizer; the temperature of the primary cooling water is 10-30 ℃, and the flow rate of the cooling water is 2-8 m ³ The water temperature of the secondary cooling water is 10-30 ℃, and the flow rate of the cooling water is 2-8 m ³ /h；

The copper ingot comprises the following components in percentage by mass: 59% -60%, al: 0.5-0.8%, sn + Fe is less than or equal to 1.0%, as is less than or equal to 0.02%, pb:1.0 to 1.8 percent of Ni, less than or equal to 0.02 percent of Si, less than or equal to 0.2 percent of Ni, less than or equal to 0.02 percent of Mn, less than or equal to 0.02 percent of Bi, the balance of Zn, and the balance of other impurities within 0.01 percent.

2. The method of producing a grade B copper ingot by horizontal continuous casting according to claim 1, wherein: the microstructure of the copper ingot obtained in the step 3) is as follows: both the edge region and the central region of the ingot are equiaxed crystal regions, the grain size of the edge region is below 15 μm, and the grain size of the middle region is below 50 μm.

3. The method of horizontal continuous casting for producing a grade B copper ingot according to claim 2, wherein: the specification of the copper ingot is phi 15-80 mm, the edge region is a region within 2-5 mm from the surface of the copper ingot, and the rest region is the middle region.

4. A method for producing a grade B copper ingot by horizontal continuous casting according to any one of claims 1 to 3, wherein: obtained in the step 3)The copper ingot obtained was polished at 100mm ² The total number of hard particles and air holes in the area is within 5.

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