CN110453106A - A kind of production process of non-vacuum lead-casting copper-iron alloy slab - Google Patents

Abstract

The invention discloses a production process of non-vacuum lead-casting copper-iron alloy flat ingots. The main steps include batching, furnace charging, smelting, refining and degassing, casting, casting and ingot cooling. Electrolytic copper plates and CuFe50 master alloy are used as The raw materials are smelted, and the copper-iron alloy ingots are successfully prepared through the non-vacuum down-drawing continuous casting process. Compared with the traditional vacuum melting and casting process, the equipment requirements are lower; at the same time, appropriate measures such as inert gas protection and adjustment of iron content are taken during the casting process, which is effective. The alloy composition and oxygen content are controlled; the invention has the advantages of stable process, simple operation and low production cost of melting and casting, and can realize the industrialized production of copper-iron alloy flat ingots.

Description

A kind of production process of non-vacuum lead-casting copper-iron alloy slab

technical field

The invention relates to the technical field of metal smelting, in particular to a production process of non-vacuum lead-casting copper-iron alloy flat ingots.

Background technique

As high-strength and high-conductivity copper-iron alloys are widely used in various industries, higher requirements are placed on the performance and manufacturing costs of such high-strength and high-conductivity copper-iron alloys. Copper-iron alloys have unique and superior characteristics, such as electromagnetic wave shielding, Elasticity, electrical conductivity, heat release, wear resistance, antibacterial properties, etc., and copper-iron alloys can be processed into various physical forms such as bars, cables, plates, films, powders, tubes, etc., and can be used in various industrial fields , with unsurpassed competitiveness and market prospects.

However, from the phase diagram of copper and iron, the two are almost completely immiscible at room temperature, the solubility at 300 °C is still zero, and the solubility at 1094 °C is only about 5%. Fe has a very low solubility in Cu. During the solidification process, it is easy to form a serious segregation structure, which seriously affects the application of CuFe alloys. Rapid solidification can refine the grains, increase the solid solubility, and is an effective way to inhibit or reduce the formation of segregation structures in CuFe alloys during solidification. , so the study of rapid solidification behavior has attracted more and more attention.

At present, there are several methods for producing CuFe alloys at home and abroad:

Vacuum arc melting method: Put a certain proportion of copper and iron blocks into a vacuum induction furnace for melting, and pour them into the mold after they are completely melted. Usually, the induction melting method and deformation aging are combined to improve the performance of copper-iron alloys. But this common induction melting method is easy to cause segregation;

Deformation in-situ composite method: The original structure of the CuFe in-situ composite material is generally a dendritic (smelting) or granular (powder metallurgy) Fe phase uniformly distributed on the Cu matrix. After a large amount of deformation, the Fe phase becomes fibrous. . In order to better improve the comprehensive properties of CuFe alloys, the deformation aging method is often used, and several steps of heat treatment are added in the middle of deformation, and it is still in the research stage;

Mechanical alloying method: A certain proportion of Cu powder and Fe powder are ground in a high-energy ball mill for a long time, so that the metal powder is continuously refined in the process of frequent collision, and finally achieves the purpose of atomic mixing and alloying. , but this method is easy to substitute impurity elements in the ball milling process, and the cost is high.

To sum up, there is still a need for a low-cost, simple-to-operate preparation process in the current market, which can industrially produce high-quality copper-iron alloy flat ingots.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the shortcomings of the above-mentioned prior art, and to provide a production process for continuous casting of copper-iron alloy slabs under non-vacuum, which has the advantages of stable process, simple and convenient operation, and low production cost of melting and casting, and can realize copper-iron alloy slabs. of industrial production.

To achieve the above object, the present invention provides the following technical solutions:

A production process for continuous casting of copper-iron alloy slabs under non-vacuum, comprising the following steps:

S1: ingredients, according to the composition ratio of copper-iron alloy, prepare 80%-95% electrolytic copper plate and 5%-20% Fe element by mass percentage, wherein Fe element is prepared in the form of CuFe50 master alloy;

S2: Load the furnace, load the raw materials into the furnace, and sequentially load the flux, the CuFe50 master alloy, the electrolytic copper plate, and the covering agent;

S3: smelting, heating the temperature of the smelting furnace to 1420-1450 °C to melt the copper-iron master alloy; heating up for melting, during the heating and melting process, gas protection should be performed at the furnace mouth;

S4: Refining and degassing, introducing argon for degassing, and using a deoxidizer for deoxidation;

S5: Casting, when the temperature reaches 1300-1450 ℃, the casting starts; if the casting temperature is too high, the gradient of the ingot will be large, the thermal stress will increase, and the crack tendency will increase. ; If the temperature is too low, the melt viscosity will be large, the fluidity will be reduced, and defects such as cold insulation and slag inclusion are easy to occur;

S6: Casting, when the melt flows into 70-85% of the square mold, turn on electromagnetic stirring, the specific parameters are as follows: frequency 3-10Hz, current 80-100A, slowly adjust the casting speed from low to high to 60-80mm/min , the mechanical vibration is 30 times/min; the casting speed determines the depth of the liquid cavity, which is a key parameter in the casting process. For flat ingots, the casting speed is too high, and the wall of the wide surface liquid cavity becomes thinner, which makes the width of the cavity in the state of tensile stress. The tensile stress of the surface layer increases, which is easy to cause cracks; if the casting speed is too low, it may cause side cracks or defects such as cold insulation on the narrow surface;

S7: The ingot is cooled, and the mold is water-cooled. At the same time, the ingot pulled out after solidification is sprayed with water at a certain angle for secondary cooling. The advantage of water cooling of the mold is that "hot top casting" can be realized inside, which reduces the solidification rate of the upper melt, ensures timely feeding and shrinkage, and is conducive to the floating and removal of slag and gas.

Preferably, the CuFe50 master alloy is smelted as follows:

The first step: batching and charging the furnace, weighing the Cu and Fe raw materials according to the proportion of the content percentage of 1:1, mixing them evenly, putting them into the crucible and placing them in the vacuum melting furnace;

The second step: vacuum induction melting, open the mechanical pump and low vacuum baffle valve to vacuumize. When P≤0.08MPa in the vacuum melting furnace, open the Roots pump; when the vacuum degree is pumped to P≤4Pa, the power of the heating device increases To 20KW-30KW, keep warm for 5min-10min; the heating power of the heating device is increased to 40KW-50KW, and the heat preservation is 5min-10min; the heating power of the heating device is increased to 60KW-70KW, after the raw materials in the crucible are uniform, reduce the heating power to 20KW, Slowly fill argon into the furnace body of the vacuum melting furnace; when the pressure in the furnace rises to 0.08Mpa, stop rushing into argon, raise the power to 70KW±5KW, and refine for 1min-2min;

The third step: casting out the furnace, reducing the power of the vacuum melting furnace to 40KW±5KW, keeping it for 0.5min and starting to pour into the casting mold, turning off the heating after the casting is completed, and cooling for 60min before releasing;

The CuFe alloy prepared by this method has a dense structure, less pores and inclusions, and no defects such as macroscopic and microscopic segregation, which ensures the quality of the final copper-iron flat ingot.

Preferably, the covering agent is quartz glass, and the usage amount is 0.25-0.50% wt of the alloy weight; the flux is a mixture of sodium silicate and fluorite, and the usage amount is 0.32-0.45% wt of the alloy medium grain.

Preferably, in S3, the Fe content is detected by sampling the crucible during smelting, and then an appropriate amount of CuFe master alloy is added accordingly to adjust the melt composition until the Fe content reaches the target value.

Preferably, in S4, the specific steps of degassing the deoxidizer include deoxidizing aluminum wire, deoxidizing CuMg alloy, and adding titanium wire before being released from the furnace.

Preferably, in S6, when the amount of melt in the crucible of the melting furnace is reduced to less than 10% of the original, the lowering speed is slowly reduced until it stops. After the ingot is completely solidified, the cooling water is turned off.

Preferably, in S7, the cooling water flow rate is gradually increased to 6.0-8.0 m3/h before the casting, the water flow rate is too high, and the cooling degree is too large, which is easy to cause stress concentration, form cold insulation, and lead to cracks; water flow rate is too low , the cooling rate of the ingot is too slow, which may cause coarse structure, performance degradation, or other defects.

Compared with the prior art, the beneficial effects of the present invention are:

(1) the present invention adopts suitable manufacturing technology for copper-iron alloy slab, especially through a large amount of technological exploration, for different specifications, a series of key parameters of non-vacuum melting and casting have been determined;

(2) the present invention uses the built-in crystallizer to electromagnetically stir the copper-iron molten liquid, increases the equiaxed crystal ratio, refines the crystal grains, reduces the surface and subcutaneous pores, inclusions, and improves the looseness and segregation of the ingot center;

(3) the copper-iron alloy slab produced by the present invention is used as the rolling stock of the copper-iron alloy strip, which reduces material loss and production cost than conventional round ingots;

(4) The present invention adopts the non-vacuum down-drawing continuous casting process, and compared with the traditional vacuum melting and casting process, the equipment requirements are low; at the same time, suitable measures such as inert gas protection and adjustment of iron content are adopted in the casting process to effectively control the alloy composition and Oxygen content, simple operation, stable and reliable.

Description of drawings

Fig. 1 is the process flow diagram of the present invention;

Fig. 2 is the physical map of embodiment 1 of the present invention;

3 is a metallographic diagram of Example 1 of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Examples 1-3:

(1) Melting steps of CuFe50 master alloy:

The first step: batching and charging the furnace, weighing the Cu and Fe raw materials according to the proportion of the content percentage of 1:1, mixing them evenly, putting them into the crucible and placing them in the vacuum melting furnace;

The second step: vacuum induction melting, open the mechanical pump and low vacuum baffle valve to vacuumize. When P≤0.08MPa in the vacuum melting furnace, open the Roots pump; when the vacuum degree is pumped to P≤4Pa, the power of the heating device increases To 20KWKW, keep warm for 5min; the heating power of the heating device is increased to 40KW, and the heat preservation is 5min; the heating power of the heating device is increased to 60KW, after the raw materials in the crucible are uniform, reduce the heating power by 20KW, and slowly fill the vacuum melting furnace with argon gas ; When the pressure in the furnace rises to 0.08Mpa, stop rushing into argon, raise the power to 65KW, and refine for 1min;

The third step: cast out the furnace, reduce the power of the vacuum melting furnace to 35KW, keep it for 0.5min and start to pour into the casting mold. After the casting is completed, turn off the heating and cool it for 60min.

(2) Casting steps of copper-iron alloy slab:

S1: ingredients, according to the composition ratio of copper-iron alloy, prepare electrolytic copper plate and Fe element in mass percentage, wherein Fe element is prepared in the form of CuFe50 master alloy;

S2: loading furnace, loading raw materials into furnace, sequentially loading flux, CuFe50 master alloy, electrolytic copper plate, and covering agent, and described covering agent is quartz glass, and described flux is a mixture of sodium silicate and fluorite;

S3: Smelting, heating the temperature of the melting furnace to 1420°C to melt the copper-iron mother alloy; heating up for melting, during the heating and melting process, gas protection should be carried out at the furnace mouth, and the Fe content should be detected by sampling the crucible during the smelting period. Add an appropriate amount of CuFe50 master alloy, adjust the melt composition until the iron content reaches the target value;

S4: Refining and degassing, introducing argon for degassing, deoxidizing aluminum wire, deoxidizing CuMg alloy, and adding titanium wire before releasing;

S5: Casting, when the temperature reaches 1300 ℃, the casting starts; if the casting temperature is too high, the inner gradient of the ingot will be large, the thermal stress will increase, and the crack tendency will increase. If it is too low, the melt viscosity will be large, the fluidity will be reduced, and defects such as cold isolation and slag inclusion are easy to occur;

S6: Casting, when the melt flows into 70% of the square mold, the electromagnetic stirring is turned on, and the specific parameters are as follows: frequency 310Hz, current 80A, slowly adjust the casting speed from low to high to 60mm/min, and mechanical vibration 30 times/min; The casting speed determines the depth of the liquid cavity, which is a key parameter in the casting process. For flat ingots, if the casting speed is too high, the wall of the liquid cavity on the wide surface becomes thinner, which increases the tensile stress of the surface layer of the wide surface that is originally in the state of tensile stress, which is easy to cause Cracks; if the casting speed is too low, it may cause side cracks or defects such as cold insulation on the narrow surface;

S7: The ingot is cooled, and the mold is water-cooled. At the same time, the ingot pulled out after solidification is sprayed with water at a certain angle for secondary cooling. The advantage of water cooling of the mold is that "hot top casting" can be realized inside, which reduces the solidification rate of the upper melt, ensures timely feeding and shrinkage, and is conducive to the floating and removal of slag and gas. The cooling water flow rate is gradually increased to 6.0m ³ /h before the casting. The water flow rate is too high and the cooling degree is too large, which is easy to cause stress concentration, form a cold barrier, and cause cracks; the water flow rate is too low, and the cooling rate of the ingot is too slow. , may result in coarse tissue, performance degradation, or other defects. When the amount of melt in the crucible of the melting furnace is reduced to less than 10% of the original, the lowering speed is slowly reduced until it stops. After the ingot is completely solidified, the cooling water is turned off.

According to the different initial ingredients, a total of 3 groups of examples were prepared, and the detailed ingredients and casting parameters are shown in Tables 1-6. Among them, the actual copper-iron flat ingot prepared in Example 1 is shown in Figure 2, and the metallographic diagram is shown in Figure 2. As shown in Figure 3, it is proved that the prepared copper-iron slab has a uniform structure and less segregation.

Table 1 Ingredients and performance table of Examples 1-3

Examples 4-6:

(1) Melting steps of CuFe50 master alloy:

The first step: batching and charging the furnace, weighing the Cu and Fe raw materials according to the proportion of the content percentage of 1:1, mixing them evenly, putting them into the crucible and placing them in the vacuum melting furnace;

The second step: vacuum induction melting, open the mechanical pump and low vacuum baffle valve to vacuumize. When P≤0.08MPa in the vacuum melting furnace, open the Roots pump; when the vacuum degree is pumped to P≤4Pa, the power of the heating device increases To 30KW, keep the temperature for 10min; the heating power of the heating device is increased to 50KW, and the heat preservation is 10min; the heating power of the heating device is increased to 70KW, after the raw materials in the crucible are uniform, reduce the heating power to 20KW, and slowly fill the vacuum melting furnace with argon When the pressure in the furnace rises to 0.08Mpa, stop rushing into argon, increase the power to 75KW, and refine for 2min;

The third step: casting out the furnace, reducing the power of the vacuum melting furnace to 45KW, keeping it for 0.5min, and starting to pour into the casting mold. After the casting is completed, turn off the heating and cool it for 60min.

(2) Smelting steps of copper-iron alloy slab:

S1: ingredients, according to the composition ratio of copper-iron alloy, prepare electrolytic copper plate and Fe element in mass percentage, wherein Fe element is prepared in the form of CuFe50 master alloy;

S2: loading furnace, loading raw materials into furnace, sequentially loading flux, CuFe50 master alloy, electrolytic copper plate, and covering agent, and described covering agent is quartz glass, and described flux is a mixture of sodium silicate and fluorite;

S3: Smelting, heating the temperature of the melting furnace to 1450°C to melt the copper-iron mother alloy; heating up for melting, during the heating and melting process, gas protection should be carried out at the furnace mouth, and the Fe content should be detected by sampling the crucible during the melting process. Add an appropriate amount of CuFe50 master alloy, adjust the melt composition until the iron content reaches the target value;

S4: Refining and degassing, introducing argon for degassing, deoxidizing aluminum wire, deoxidizing CuMg alloy, and adding titanium wire before releasing;

S5: Casting, when the temperature reaches 1450 ℃, the casting starts; (if the casting temperature is too high, the gradient of the ingot will be large, the thermal stress will increase, the crack tendency will increase, and the liquid cavity wall will become thinner, which is prone to wide-face cracks; If the temperature is too low, the melt viscosity will be large, the fluidity will be reduced, and defects such as cold insulation and slag inclusion are easy to occur;

S6: Casting, when the melt flows into 85% of the square mold, turn on electromagnetic stirring, the specific parameters are as follows: frequency 10Hz, current 100A, slowly adjust the casting speed from low to high to 80mm/min, and mechanical vibration 30 times/min; The casting speed determines the depth of the liquid cavity, which is a key parameter in the casting process. For flat ingots, if the casting speed is too high, the wall of the liquid cavity on the wide surface becomes thinner, which increases the tensile stress of the surface layer of the wide surface that is originally in the state of tensile stress, which is easy to cause Cracks; if the casting speed is too low, it may cause side cracks or defects such as cold insulation on the narrow surface;

S7: The ingot is cooled, and the mold is water-cooled. At the same time, the ingot pulled out after solidification is sprayed with water at a certain angle for secondary cooling. The advantage of water cooling of the mold is that "hot top casting" can be realized inside, which reduces the solidification rate of the upper melt, ensures timely feeding and shrinkage, and is conducive to the floating and removal of slag and gas. The cooling water flow rate is gradually increased to 8.0m ³ /h before the casting. The water flow rate is too high, and the cooling degree is too large, which is easy to cause stress concentration, form a cold barrier, and cause cracks; the water flow rate is too low, and the cooling rate of the ingot is too slow. , may result in coarse tissue, performance degradation, or other defects. When the amount of melt in the crucible of the melting furnace is reduced to less than 10% of the original, the lowering speed is slowly reduced until it stops. After the ingot is completely solidified, the cooling water is turned off.

According to different initial ingredients, a total of 3 groups of examples were prepared, and the detailed ingredients and casting parameters are shown in Table 2.

The ingredients and performance table of table 2 embodiment 4-6

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that it can still be The technical solutions described in the foregoing embodiments are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the present invention.

Claims (7)

1. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind is antivacuum, which comprises the following steps:

S1: ingredient, according to the preset blending ratio of copper-iron alloy, by percentage to the quality, prepare 80%~95% electrolytic copper plate and The Fe element of 5%-20%, wherein Fe element is prepared in the form of CuFe50 master alloy；

S2: raw material is carried out shove charge by shove charge, is sequentially loaded into flux, CuFe50 master alloy, electrolytic copper plate, coverture；

S3: melting furnace temperature is heated to 1420~1450 DEG C by melting, melts copper and iron master alloy, in heating fusion process, Gas shield is carried out in fire door；

S4: refining degasification is passed through argon gas and carries out degasification, and carries out deoxidation using deoxidier；

S5: casting starts to cast when temperature reaches 1300-1450 DEG C；

S6: casting opens electromagnetic agitation, 3~10Hz of setpoint frequency, electric current when the 70~85% of melt inflow side crystallizer Casting speed is slowly adjusted to 60~80mm/min from down to high by 80~100A, and 30 beats/min of mechanical oscillation；

S7: ingot casting is cooling, sprays water at a certain angle using crystallizer water cooling, while to the ingot casting extracted after solidification, carries out secondary It is cooling.

2. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind according to claim 1 is antivacuum, it is characterised in that: The CuFe50 master alloy melting by the following method:

Step 1: ingredient shove charge, weighs Cu, Fe raw material according to the ratio that percentage composition is 1:1, is packed into crucible after mixing It puts to vacuum melting furnace；

Step 2: vacuum induction melting: when vacuum degree is extracted into P≤4Pa, heating device power rises to 20KW-30KW, heat preservation 5min-10min；Heating devices heat power rises to 40KW-50KW, keeps the temperature 5min-10min；Heating devices heat power rises to 60KW-70KW reduces heating power to 20KW, slowly to vacuum melting furnace body after raw material in crucible reaches uniformly up and down Inside it is filled with argon gas；When furnace pressure rises to 0.08Mpa, argon gas is poured in stopping, and power per liter to 70KW ± 5KW refines 1min- 2min；

Step 3: casting is come out of the stove, vacuum melting furnace power is reduced to 40KW ± 5KW, 0.5min is kept to start into casting die It casts, heating is closed after the completion of casting, is come out of the stove after cooling 60min.

3. drawing the production technology of continuous casting copper-iron alloy slab ingot under antivacuum according to one kind described in claim 1, it is characterised in that: institute Stating coverture is quartz glass, and usage amount is the 0.25-0.50%wt of weight alloy；The flux is the mixed of sodium metasilicate and fluorite Object is closed, usage amount is the 0.32-0.45%wt of weight alloy.

4. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind according to claim 1 is antivacuum, it is characterised in that: In S3, crucible sample detection Fe content is used during melting, adds suitable CuFe master alloy accordingly, adjustment bath composition until Iron content reaches target value.

5. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind according to claim 1 is antivacuum, it is characterised in that: In S4, deoxidier degasification the specific steps are aluminium wire deoxidation, the deoxidation of CuMg alloy, come out of the stove before be added titanium silk.

6. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind according to claim 1 is antivacuum, it is characterised in that: In S6, when melt amount is reduced to 10% or less original in smelting furnace crucible, speed is drawn under slowly reducing until stopping.Wait cast After ingot solidifies completely, cooling water is closed.

7. drawing the production technology of continuous casting copper-iron alloy slab ingot under one kind according to claim 1 is antivacuum, it is characterised in that: In S7, cooling water flow is gradually increased to 6.0~8.0m before the casting³/h。