CN108655352A - Preparation method of iron foil - Google Patents

Abstract

The invention relates to a method for preparing iron foil, which includes: 1) melting industrial pure iron in an intermediate frequency furnace, the composition of which is consistent with that of iron foil; The spray bag is a molten steel container with a nozzle; the molten industrial pure iron is sprayed from the nozzle of the spray bag, and is rapidly condensed into an ultra-thin iron foil with a thickness of 10-30 μm on the high-speed rotating water-cooled copper roller; 3) Iron foil Throw it out along the tangential direction of the copper roller, and realize online curling into rolls by the coiler. In the present invention, industrial pure iron is directly cast into iron foil, which saves multiple processes such as rolling and reheating, and has low preparation cost and high production efficiency; at the same time, the cooling speed of industrial pure iron can be controlled by controlling the rotation speed of water-cooled copper rollers , and then obtain iron foils of different thickness specifications, which is flexible and convenient to operate.

Description

A kind of preparation method of iron foil

technical field

The invention relates to the technical field of metal material preparation, in particular to a method for preparing iron foil.

Background technique

Iron foil refers to very thin metal iron, which can be widely used in magnetic shielding materials, nickel-cadmium batteries with high energy storage density and packaging materials. The invention patent with the publication number CN104134802A discloses a "lithium battery", which uses iron foil as the current collector of the negative electrode of the lithium battery, replacing copper foil, which greatly reduces the raw material cost of the battery.

Conventional iron foil preparation methods include cold rolling method, electrolysis method and so on. The invention patent with the publication number CN102688885A discloses "a method for preparing synchronous cold-rolled iron foil by lamination method". It uses several pieces of thick and thin iron sheets, and the thick and thin sheets form a laminated structure. The layered materials are heat treated, and lubricating materials are applied between the layers, and the combined layered structure is sent to a common two-roll or four-roll mill for cold rolling and thinning. The sheet is thinned to the desired thickness of iron foil. The invention patent with the publication number CN1066478A discloses a "method for preparing pure iron foil by electrolytic forming", which is characterized in that a soluble anode is used, and the aqueous electrolyte solution is composed of FeCl ₂ 6H ₂ O and a small amount of stabilizer and wetting agent. The cathode current density used is 0.01-0.35A/cm ² , and the pure iron foil with a thickness of 20-100 microns and a purity of 99.89% is electrolytically deposited in an acid electrolyte solution with a pH of 0.1-3.5.

At present, whether it is cold rolling or electrolytic method to prepare iron foil, there are problems such as complex process, high cost and low efficiency.

Contents of the invention

The invention provides a method for preparing iron foil, which adopts industrial pure iron to directly cast iron foil, saves multiple processes such as rolling and reheating, has low preparation cost and high production efficiency; The rotation speed controls the cooling speed of industrial pure iron, and then obtains iron foils of different thickness specifications, which is flexible and convenient to operate.

In order to achieve the above object, the present invention adopts the following technical solutions to realize:

A method for preparing iron foil, comprising the steps of:

1) Industrial pure iron is melted in an intermediate frequency furnace. The composition of industrial pure iron is consistent with that of iron foil. The weight percentage of specific components is: C≤0.0030%; Si≤0.01%; Mn≤0.04%; P≤0.005%; S≤0.002%; Al≤0.005%; Fe≥99.8%; the rest are unavoidable impurities;

2) The molten industrial pure iron enters the injection ladle through the tundish, and the injection ladle is a molten steel container with a nozzle; the molten industrial pure iron is sprayed from the nozzle of the injection ladle, and condenses rapidly on the high-speed rotating water-cooled copper roller Ultra-thin iron foil with a thickness of 10-30 μm;

3) The iron foil is thrown out along the tangential direction of the water-cooled copper roller, and is coiled online by the coiler.

The tundish has the function of heating and heat preservation, the temperature of the melted industrial pure iron in the tundish is controlled above 1400°C, and the temperature deviation of the industrial pure iron melt in the tundish during casting is less than 5°C.

Automatically detect the liquid level in the tundish and spray bag to ensure that the fluctuation of the liquid level is less than ±3mm during the iron foil preparation process.

The nozzles of the spraying package adopt BN nozzles, and the distance between the nozzles and the water-cooled copper roller surface is detected and adjusted in real time when the iron foil is prepared, so as to ensure that the industrial pure iron melt flows to the water-cooled copper roller in a "plane flow" manner. roll surface.

When the water-cooled copper roller is running, the runout of the roller surface in the radial and axial directions is less than 5 μm, and the surface roughness of the water-cooled copper roller is 1.5-2.0 μm.

The rotation speed of the water-cooled copper roll is 10-50m/s, and the cooling speed of the industrial pure iron melt on the roll surface is 10 ⁴ -10 ⁶ ℃/s.

The coiler is equipped with a current double closed-loop tension control system, and the tension can be set according to the needs; when coiling, the linear speed of the reel is synchronized with the linear speed of the water-cooled copper roller. After that, immediately control the current of the DC motor of the coiler to keep constant, and then automatically control the DC motor speed to decrease accordingly with the increase of the diameter of the iron foil coil.

One side of the water-cooled copper roller is equipped with a roller surface cleaning device and a turning device. The cleaning roller of the roller surface cleaning device is closely attached to the surface of the water-cooled copper roller to realize online cleaning. The turning device is used for partial or large areas of the water-cooled copper roller surface after shutdown. clean up.

Compared with prior art, the beneficial effect of the present invention is:

1) Industrial pure iron is used to directly cast iron foil, eliminating the need for multiple processes such as rolling and reheating. Compared with the existing iron foil preparation process, it has simple process, low cost and high production efficiency;

2) By controlling the rotation speed of the water-cooled copper roller to control the cooling speed of industrial pure iron, iron foils of different thickness specifications can be obtained, and the operation is flexible and convenient.

Description of drawings

Fig. 1 is a process flow diagram of the iron foil preparation method of the present invention.

In the figure: 1. Intermediate frequency furnace 2. Tundish 3. Liquid level detection device 4. Spray bag 5. Spray distance measurement device 6. Turning device 7. Roll surface cleaning device 8. Water-cooled copper roll 9. Coiler

Detailed ways

The specific embodiment of the present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, a kind of preparation method of iron foil of the present invention comprises the following steps:

1) Industrial pure iron is melted in the intermediate frequency furnace 1, the composition of industrial pure iron is consistent with that of iron foil, and the weight percentage of specific components is: C≤0.0030%; Si≤0.01%; Mn≤0.04%; P≤0.005% ; S≤0.002%; Al≤0.005%; Fe≥99.8%; the rest are unavoidable impurities;

2) The industrial pure iron after melting enters the injection bag 4 through the tundish 2, and the injection bag 4 is a molten steel container provided with a nozzle; Quickly condense on the roller 8 into an ultra-thin iron foil with a thickness of 10-30 μm;

3) The iron foil is thrown out along the tangential direction of the water-cooled copper roller 8, and is curled into rolls online by the coiler 9.

The tundish 2 has the function of heating and heat preservation. The temperature of the molten industrial pure iron in the tundish 2 is controlled above 1400°C, and the temperature deviation of the industrial pure iron melt in the tundish 2 is less than 5°C during the casting process.

The liquid level in the tundish 2 and the jetting bag 4 is automatically detected to ensure that the fluctuation of the liquid level is less than ±3mm during the iron foil preparation process.

The nozzles of the injection package 4 adopt BN nozzles. When preparing the iron foil, the distance between the nozzles and the surface of the water-cooled copper roller 8 is detected and adjusted in real time, so as to ensure that the industrial pure iron melt flows to the water-cooled roller in a "plane flow" manner. Copper Kun 8 roll surface.

When the water-cooled copper roller 8 is running, the radial and axial runout of the roller surface is less than 5 μm, and the surface roughness of the water-cooled copper roller 8 is 1.5-2.0 μm.

The rotation speed of the water-cooled copper roll 8 is 10-50 m/s, and the cooling rate of the industrial pure iron melt on the roll surface is 10 ⁴ -10 ⁶ °C/s.

The coiler 9 is equipped with a current double-closed-loop tension control system, and the tension can be set according to needs; when coiling, the linear speed of the reel is synchronized with the linear speed of the water-cooled copper roller 8, and when the coiler 9 grabs the iron foil leader And after setting up the tension force, immediately control the current of the coiler 9 DC motors to keep constant, then automatically control the corresponding reduction of the DC motor speed along with the increase of the iron foil coil diameter.

One side of the water-cooled copper roller 8 is equipped with a roller surface cleaning device 7 and a turning device 6. The cleaning roller of the roller surface cleaning device 7 is closely attached to the surface of the water-cooled copper roller 8 to realize online cleaning. The turning device 6 is used for the water-cooled copper roller 8 after shutdown. Partial or large area cleaning of the roller surface.

The intermediate frequency furnace 1 adopts a closed furnace cover, and the entire process of the industrial pure iron melt flowing from the intermediate frequency furnace 1 to the tundish 2 and the injection ladle 4 takes closed protection measures to prevent air or other oxygen sources from contacting the industrial pure iron melt. Ensure that the chemical composition of the iron foil is stable.

The industrial pure iron melt in the tundish 2 is heated and kept for the purpose of improving the product quality of the iron foil and the stability of the preparation process.

Automatically detect the liquid level in the tundish 2 and the injection bag 4 to prevent the liquid level from fluctuating too much. The purpose is to stabilize the flow pressure of the industrial pure iron melt and improve the forming quality of the iron foil.

Control the rotation speed of the water-cooled copper roller 8, and ensure the cooling speed of the industrial pure iron melt by rationally designing the cooling channel structure inside the water-cooled copper roller 8. The purpose is to obtain iron foil products that meet the performance and size requirements through high cooling speed . The radial runout and axial runout of the water-cooled copper roller 8 are controlled, and the roughness accuracy of the roll surface is ensured. The purpose is to ensure the stable and reliable operation of the equipment in the iron foil preparation process, so as to improve the quality and production stability of the iron foil.

The following examples are carried out on the premise of the technical solutions of the present invention, and detailed implementation methods and specific operation processes are provided, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

【Example】

In this embodiment, the process of preparing the iron foil is shown in FIG. 1 .

Use the liquid level detection device 3 to detect the liquid level of the industrial pure iron melt in the tundish 2 and the injection bag 4 in real time, and stop production when the liquid level is lower than the set value; The distance between the water-cooled copper roller 8 and the roller surface is detected in real time, and the position of the water-cooled copper roller 8 is adjusted online according to the measurement results to ensure the best spraying distance; Clean up to ensure that the cleanliness of the roller surface meets the requirements for iron foil preparation; use the water-cooled copper roller 8 to realize the cooling and forming of the iron foil; use the coiler 9 to curl the prepared iron foil.

In this embodiment, the specific steps of iron foil preparation are as follows:

1) Melt 200kg of industrial pure iron in a medium frequency induction furnace with a volume of 500kg. The intermediate frequency induction furnace adopts a closed furnace cover with a melting temperature of 1550°C. The composition of industrial pure iron is shown in the table below:

Composition of industrial pure iron, %

C Si mn P S al Fe 0.0018 0.0050 0.03 0.003 0.0015 0.003 99.9

2) The molten industrial pure iron flows into the injection ladle after passing through the tundish. The tundish capacity is 50t, and the injection ladle adopts a steel ladle with a capacity of 20t and a BN (boron nitride) nozzle. The entire casting process is in a vacuum casting state; using the liquid level The detection device 3 controls the fluctuation of the liquid level in the tundish and the injection ladle to be less than 3mm, and the tundish adopts plasma heating technology to control the temperature deviation of the molten steel in the tundish within ±5°C during the entire casting process.

3) The industrial pure iron melt is sprayed to the high-speed rotating water-cooled copper roller through the BN nozzle. The speed of the water-cooled copper roller is 20m/s, and the surface roughness is 1.6μm. The runout in the direction is less than 3μm, and the distance from the nozzle to the surface of the water-cooled copper roll is set at 10mm.

The design principle of the cooling water channel inside the water-cooled copper roller is: since the heat exchange between the cooling water and the surface layer of the water-cooled copper roller is only carried out in the water layer near the contact surface, the heat transfer coefficient increases with the increase of the water flow velocity, so it must be considered in the design to overcome The flow resistance of the water should not block the water flow due to scaling and corrosion of the water jacket, and at the same time make the cooling water flow channel as narrow as possible so that a higher flow rate can be achieved when the water flow rate is constant.

The industrial pure iron melt solidifies on the surface of the water-cooled copper roll to form an iron foil with a thickness of 20 μm. After the formed iron foil rotates with the water-cooled copper roll, it is thrown out along the tangential direction. After the coiler grabs the lead of the iron foil and establishes tension, Keep the coiling DC motor current constant, the motor speed will automatically decrease with the increase of iron foil coil diameter, and finally complete the online coiling process.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Any equivalent replacement or change of the inventive concepts thereof shall fall within the protection scope of the present invention.

Claims (8)

1. a kind of preparation method of iron foil, which is characterized in that include the following steps：

1) ingot iron is melted in intermediate frequency furnace, the ingredient of ingot iron is consistent with iron foil ingredient, the weight percent of specific ingredient It is than content：C≤0.0030%；Si≤0.01%；Mn≤0.04%；P≤0.005%；S≤0.002%；Al≤0.005%； Fe >=99.8%；Remaining is inevitable impurity；

2) ingot iron after melting enters injection packet by tundish, and injection packet is the steel in water container equipped with nozzle；After fusing Ingot iron sprayed from the nozzle of injection packet, rapid condensation is 10~30 μm of thickness in high-speed rotating water-cooled copper roller Ultra-thin iron foil；

3) iron foil is thrown away along water-cooled copper roller tangential direction, realizes that online curling is coiled by coiling machine.

2. a kind of preparation method of iron foil according to claim 1, which is characterized in that the tundish has heating and thermal insulation Function, ingot iron after the fusing temperature in tundish is controlled at 1400 DEG C or more, and technical pure in casting process tundish The temperature deviation of fusant is less than 5 DEG C.

3. a kind of preparation method of iron foil according to claim 1, which is characterized in that the liquid in tundish and injection packet Position is detected automatically, ensures that liquid fluctuating is less than ± 3mm in iron foil preparation process.

4. a kind of preparation method of iron foil according to claim 1, which is characterized in that the nozzle of the injection packet uses BN Nozzle is measured in real time and adjusts to the distance between nozzle to water-cooled copper roller roll surface when preparing iron foil, ensures ingot iron Melt is flowed in a manner of " planar flow " on water-cooled copper Kun roll surfaces.

5. a kind of preparation method of iron foil according to claim 1, which is characterized in that the faces Kun are along diameter when water-cooled copper roller operates 5 μm are respectively less than to axial bounce, the surface roughness of water-cooled copper roller is 1.5~2.0 μm.

6. a kind of preparation method of iron foil according to claim 1, which is characterized in that the velocity of rotation of water-cooled copper roller is 10 ~50m/s, cooling velocity of the ingot iron melt on roll surface are 10⁴~10⁶℃/s。

7. a kind of preparation method of iron foil according to claim 1, which is characterized in that coiling machine sets current double closed-loop tension The size of control system, tension is set as needed；When batching, keep the linear velocity of rolling wheel synchronous with the linear velocity of water-cooled copper Kun, After coiling machine catches iron foil to take the lead and establishes tension, the constant current hold of coiling machine direct current generator is immediately controlled, then with The increase for iron foil coil diameter automatically controls DC generator speed and accordingly reduces.

8. a kind of preparation method of iron foil according to claim 1, which is characterized in that water-cooled copper roller side sets roll surface cleaning Device and truning fixture, the cleaning roller of roll surface cleaning device, which is tightly attached on the surface of water-cooled copper roller, realizes Hand scarf, turning dress It sets for the part of water-cooled copper roller roll surface after shutdown or large area cleaning.