A process for producing and forming steel ingots based on energy-saving and environmentally friendly

Abstract

The present invention provides a process for producing and forming steel ingots based on energy conservation and environmental protection, and the process comprises the following steps: step S1, conveying scrap steel and scrap iron into a medium frequency furnace for smelting, and smelting the scrap steel and scrap iron into molten steel; step S2, conveying the molten steel into a ladle for storage and transportation, and transferring the molten steel in the ladle to a refining furnace; step S3, adding calcium oxide into the refining furnace to remove silicon in the molten steel, and increasing the temperature of the molten steel, and then conveying the molten steel to a de-impurity furnace; step S4, vacuuming the molten steel through an exhaust pipe in the de-impurity furnace, removing gas in the molten steel, and preventing the molten steel from generating bubbles; step S5, then heating the molten steel in the de-impurity furnace and conveying the molten steel into the ladle, and then transferring the molten steel to a center pouring pipe through the ladle for pouring, and pouring the molten steel into a mold for ingot forming. During pouring, protective slag is poured into the molten steel to maintain the temperature of the uppermost layer of the molten steel. The present invention can better achieve ingot forming.

Description

Technical Field

[0001] The invention relates to the technical field of steel ingot production, in particular to a process for producing and forming steel ingots based on energy conservation and environmental protection. Background Art

[0002] Steel ingots can be produced through electroslag smelting, ingot casting, and forging / rolling processes. To ensure the final mechanical properties and structural uniformity of the product, large-section ingots are generally cast and then forged into finished products using hydraulic presses, rapid presses, and other facilities, or forged into small-section billets, and then rolled into bars of the final diameter. A typical processing procedure in traditional processing technology is: the ingots are smelted and cast in an electric furnace, heated in a steel ingot soaking furnace, and then forged to 1200°C using a hydraulic press or hydraulic rapid forging press to form small-section square billets; the billets are transported to the rolling mill, heated in a heating furnace, and then rolled into the final cross-section round steel bars by the bar mill unit, which are then finished and stored in the finished product warehouse. Because the deformation resistance of high-alloy materials increases sharply below 1000℃, the deformation temperature range of such materials is generally controlled between 1000℃ and 1200℃. After multiple processing and deformation, the temperature drop is relatively high, so it is necessary to enter the heating furnace several times for supplementary heating. Traditional forging requires multiple intermittent heating, and the processing and manufacturing process is long. At the same time, when using the forging process to roll large-section steel ingots into small-section billets or finished products, the production capacity is low, the production efficiency is low, the yield rate is low, and the production cost is high.

[0003] In the prior art, many impurities will appear in the molten steel during the smelting process, such as air impurities, which will cause bubbles in the molten steel. In addition, due to the refractory materials during smelting, silicon impurities will be generated and enter the molten steel. Moreover, during the pouring of molten steel, the temperature of the top layer of the molten steel cannot be maintained, which will lead to too rapid cooling, resulting in an increase in waste on the surface of the ingot and a high scrap rate after the ingot is formed. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a process for producing and forming steel ingots based on energy conservation and environmental protection, which can realize steel ingot forming, remove impurities in molten steel, and reduce the scrap rate of steel ingot forming.

[0005] The present invention is achieved by the following method: a process for producing and forming energy-saving and environmentally friendly steel ingots, the process comprising the following steps:

[0006] Step S1: transporting scrap steel and scrap iron to a medium frequency furnace for smelting, and smelting the scrap steel and scrap iron into molten steel;

[0007] Step S2: transferring the molten steel into a ladle for storage and transfer, and transferring the molten steel in the ladle into a refining furnace;

[0008] Step S3: adding calcium oxide into the refining furnace to remove silicon from the molten steel and increase the temperature of the molten steel, and then transferring the molten steel to the impurity removal furnace;

[0009] Step S4: vacuuming the molten steel through an exhaust pipe in the impurity removal furnace to remove gas in the molten steel and prevent bubbles from forming in the molten steel;

[0010] Step S5: The impurity removal furnace heats the molten steel and transfers it to the ladle. The ladle is then transferred to the center pouring pipe for pouring, and poured into the mold to form the ingot. During the pouring, protective slag is poured into the molten steel to maintain the temperature of the uppermost layer of the molten steel, so that the ingot can be better formed.

[0011] Furthermore, the medium frequency furnace includes a pit body opened on the ground, induction coils are provided at the left and right ends and the bottom of the pit body, red mud is filled between the two induction coils, refractory materials are paved on the surface of the induction coils to form a furnace body, and a pressing part for pressing steel smelting raw materials into the furnace body is provided on the ground, the pressing part includes a U-shaped base, two vertical plates of the U-shaped base are provided on both sides of the furnace body, a dual-output motor is provided in the middle of the horizontal plate of the U-shaped base, a diverter is provided at the end of the output shaft of the dual-output motor, a screw is connected to the output end of the diverter, and strip grooves are provided on the upper surfaces of the two vertical plates of the U-shaped base, the screw is provided in the strip groove, a sliding block is spirally sleeved on the screw, a U-shaped frame is provided on the sliding blocks at the left and right ends, a multi-section telescopic cylinder is embedded in the horizontal plate of the U-shaped frame, and a pressing plate is provided at the end of the telescopic rod of the multi-section telescopic cylinder.

[0012] Furthermore, the intermediate frequency furnace, refining furnace, impurity removal furnace and mold are arranged from left to right, and a gantry is provided on the intermediate frequency furnace, refining furnace, impurity removal furnace and mold, and a transport crane for transferring the ladle is provided on the gantry.

[0013] Furthermore, a graphite electrode is provided on the upper surface of the refining furnace, a feed pipe is connected to the left side of the refining furnace, a storage box for storing calcium oxide is provided at the feed port of the feed pipe, and a solenoid valve is provided in the feed pipe.

[0014] Furthermore, the center pouring pipe is arranged in the middle of the mold, and a plurality of pouring channels are opened at equal distances on the bottom surface of the mold, and the pouring channels are connected to the center pouring pipe.

[0015] The beneficial effects of the present invention are as follows: the present invention can realize the removal of silicon impurities in molten steel and gas impurities in the air, thereby removing bubbles in the molten steel and increasing the yield of the steel ingots; by adding protective slag, the temperature of the uppermost layer of the molten steel can be maintained, thereby maintaining the cooling temperature of the molten steel during the ingot forming and reducing the scrap rate after the ingot is formed; the present invention can make full use of the physical heat of the molten steel, avoid the remelting process of the metal ingot by the electric slag remelting method, save electricity consumption, and thus achieve energy-saving and environmentally friendly operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the present invention.

[0018] Figure 3 This is a structural diagram of the medium frequency furnace.

[0019] Figure 4 It is a structural diagram of the U-shaped base. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] See also Figure 1 As shown, the present invention provides: a process for producing and forming energy-saving and environmentally friendly steel ingots, the process comprising the following steps:

[0022] Step S1, transporting scrap steel and scrap iron to the medium frequency furnace 1 for smelting, and smelting the scrap steel and scrap iron into molten steel;

[0023] Step S2: transferring the molten steel into the ladle 2 for storage and transfer, and transferring the molten steel in the ladle 2 to the refining furnace 3;

[0024] Step S3: adding calcium oxide into the refining furnace 3 to remove silicon from the molten steel and increase the temperature of the molten steel, and then transferring the molten steel to the impurity removal furnace 4;

[0025] Step S4: vacuuming the molten steel through the exhaust pipe 5 in the impurity removal furnace 4 to remove gas in the molten steel and prevent bubbles from forming in the molten steel;

[0026] Step S5, then the impurity removal furnace 4 heats the molten steel and transports the molten steel to the ladle 2, and then transfers it to the center pouring pipe 6 through the ladle 2 for pouring, and pours it into the mold 7 to form an ingot. During pouring, protective slag is poured into the molten steel to maintain the temperature of the top layer of the molten steel, so that the ingot can be better formed.

[0027] Please continue reading Figure 3 and Figure 4As shown, in one embodiment of the present invention, the intermediate frequency furnace 1 includes a pit body 11 opened in the ground, induction coils 12 are provided at both ends and the bottom of the pit body, red mud 13 is filled between the two induction coils 12, and refractory materials 14 are laid on the surface of the induction coils 12 to form a furnace body, and a pressing piece 8 for pressing steel smelting raw materials into the furnace body is provided on the ground, and the pressing piece 8 includes a U-shaped base 81, two vertical plates of the U-shaped base 81 are provided on both sides of the furnace body, and a horizontal plate of the U-shaped base 81 is provided in the middle. There is a dual-output motor 82, and a steering gear 83 is provided at the end of the output shaft of the dual-output motor 82. The output end of the steering gear 83 is connected to a screw 84. The upper surface of the two vertical plates of the U-shaped base 81 is provided with a strip groove (not shown), and the screw 84 is arranged in the strip groove. A sliding block 85 is spirally sleeved on the screw 84, and a U-shaped frame 86 is provided on the sliding blocks 85 at the left and right ends. A multi-section telescopic cylinder 87 is embedded in the horizontal plate of the U-shaped frame 86, and a pressing plate 88 is provided at the end of the telescopic rod of the multi-section telescopic cylinder 87. Through the action of the induction coil 12, the smelting of scrap iron and scrap steel can be achieved, the red mud 13 can achieve the effects of insulation and heat insulation to avoid damage to the induction coil 12, and through the action of the pressing piece 8, the upper material can be better pressed downward, which is convenient for steel smelting; the dual-output motor 82 drives the screw 84 to rotate through the steering gear 83, and the rotation of the screw 84 can drive the sliding block 85 to move back and forth, thereby realizing the back and forth movement of the U-shaped frame 86, which is convenient for scrap steel and scrap iron to enter the furnace body, and then the multi-section telescopic cylinder 87 can drive the pressing plate 88 to rise and fall, thereby pressing the material downward, which is convenient for the material to be better smelted.

[0028] Please continue reading Figure 2 As shown, in one embodiment of the present invention, the intermediate frequency furnace 1, refining furnace 3, impurity removal furnace 4 and mold 7 are arranged from left to right. A gantry 9 is mounted on the intermediate frequency furnace 1, refining furnace 3, impurity removal furnace 4 and mold 7. A transport crane 91 for transferring the ladle is mounted on the gantry 9. The transport crane 91 enables the ladle 2 to be transferred.

[0029] Please continue reading Figure 2 As shown, in one embodiment of the present invention, a graphite electrode 31 is provided on the upper surface of the refining furnace 3. A feed pipe 32 is connected to the left side of the refining furnace 3. A storage tank 33 for storing calcium oxide is provided at the feed port of the feed pipe 32. A solenoid valve 34 is provided within the feed pipe 32. Calcium fluoride in the storage tank 33 is transported into the refining furnace 3 through the feed pipe 32, where it reacts with silicon in the molten steel, thereby removing silicon impurities from the molten steel.

[0030] Please continue reading Figure 2As shown, in one embodiment of the present invention, the center pouring pipe 6 is disposed in the middle of the mold 7, and a plurality of pouring channels 71 are equidistantly provided on the bottom surface of the mold 7. The pouring channels 71 are connected to the center pouring pipe 6. This allows molten steel to be poured into the center pouring pipe 6 and then overflow into the mold 7 through the pouring channels 71 until the mold 7 is completely filled. This prevents uneven temperature of the molten steel. Continuous mold slag is added during the casting process to maintain the temperature of the uppermost layer of the molten steel.

[0031] The present invention adds different types of protective slag according to the differences in products, generally at a ratio of 0.5-1.5 kg / ton. Different products, such as high carbon, low carbon, medium carbon, high chromium, etc., are added according to the weight of the ingot. Generally, small ones (1-5 tons) are added once, medium ones (5-15 tons) are added twice, and those above 15 tons are generally added three times. CB-3 is used for high chromium, CB-1 is used for medium carbon, and CB-2 is used for low carbon or medium carbon. CB-1, CB-2 and CB-3 are all mold casting protective slags, which are existing technologies and will not be described in detail here.

[0032] The multi-section telescopic cylinder, transport crane, dual-output motor, steering gear, solenoid valve, refining furnace, impurity removal furnace and graphite electrode in the present invention are all existing technologies, which are clearly understood by those skilled in the art and will not be described in detail here.

[0033] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A process for producing and forming energy-saving and environmentally friendly steel ingots, characterized in that: The process comprises the following steps: Step S1: transporting scrap steel and scrap iron to a medium frequency furnace for smelting, and smelting the scrap steel and scrap iron into molten steel; Step S2: transferring the molten steel into a ladle for storage and transfer, and transferring the molten steel in the ladle into a refining furnace; Step S3: adding calcium oxide into the refining furnace to remove silicon from the molten steel and increase the temperature of the molten steel, and then transferring the molten steel to the impurity removal furnace; Step S4: vacuuming the molten steel through an exhaust pipe in the impurity removal furnace to remove gas in the molten steel and prevent bubbles from forming in the molten steel; Step S5, then the impurity removal furnace heats the molten steel and transports the molten steel into the ladle, and then transfers it to the center pouring pipe through the ladle for pouring, and pours it into the mold to form the ingot. During pouring, protective slag is poured into the molten steel to maintain the uppermost temperature of the molten steel, so that the ingot can be better formed; the medium frequency furnace includes a pit body opened on the ground, and the left and right ends and the bottom of the pit body are provided with induction coils, and red mud is filled between the two induction coils. The surface of the induction coil is paved with refractory materials to form a furnace body, and a pressing piece for pressing the steel smelting raw materials into the furnace body is provided on the ground. The pressing part includes a U-shaped base, and the two vertical plates of the U-shaped base are arranged on both sides of the furnace body. A dual-output motor is arranged in the middle of the horizontal plate of the U-shaped base, and a diverter is arranged at the end of the output shaft of the dual-output motor. The output end of the diverter is connected to a screw, and the upper surface of the two vertical plates of the U-shaped base is provided with a strip groove, and the screw is arranged in the strip groove. A sliding block is spirally sleeved on the screw, and a U-shaped frame is provided on the sliding blocks at the left and right ends. A multi-section telescopic cylinder is embedded in the horizontal plate of the U-shaped frame, and a pressing plate is provided at the end of the telescopic rod of the multi-section telescopic cylinder.

2. The process for producing and forming energy-saving and environmentally friendly steel ingots according to claim 1 is characterized in that: The intermediate frequency furnace, refining furnace, impurity removal furnace and mold are arranged from left to right. A gantry is mounted on the intermediate frequency furnace, refining furnace, impurity removal furnace and mold. A transport crane for transferring the ladle is mounted on the gantry.

3. The process for producing and forming energy-saving and environmentally friendly steel ingots according to claim 1 is characterized in that: A graphite electrode is provided on the upper surface of the refining furnace, a feed pipe is connected to the left side of the refining furnace, a storage box for storing calcium oxide is provided at the feed port of the feed pipe, and a solenoid valve is provided in the feed pipe.

4. The process for producing and forming an energy-saving and environmentally friendly steel ingot according to claim 1 is characterized in that: The center pouring pipe is arranged in the middle of the mold, and a plurality of pouring channels are opened at equal distances on the bottom surface of the mold, and the pouring channels are connected to the center pouring pipe.

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