Smelting method of ultralow-carbon automobile steel capable of reducing carbon emission

Abstract

The invention relates to a smelting method of ultra-low carbon automobile steel capable of reducing carbon emission, which comprises the following steps of: carrying out converter blowing on semi-steel obtained by mixing electric furnace molten steel accounting for 30wt%-70wt% of the total amount and blast furnace molten iron accounting for 70wt%-30wt% of the total amount, and the converter blowing comprises the steps of molten iron pretreatment, converter smelting, LF (ladle furnace) refining, RH (relative humidity) operation and continuous casting. The method has the beneficial effects that (1) the mixed semisteel of the electric furnace molten steel and the blast furnace molten iron is adopted for converter blowing, so that a heat source required by converter smelting is ensured, and carbon emission generated in the blowing process can be effectively reduced; 2) the semisteel process reduces the carbon content of the material entering the converter, and effectively reduces the discharge amount of oxycarbide; and (3) the non-metallic inclusions and the performance of the finished product meet the requirements of ultra-low carbon automobile steel products.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical manufacturing, and in particular relates to a smelting method of ultra-low carbon automobile steel with reduced carbon emissions. Background Art

[0002] As a typical resource and energy intensive industry, the steel industry's total energy consumption accounts for about 11% of the country's total energy consumption, and its carbon emissions account for about 15% of the country's total carbon emissions. It is the "main battlefield" for energy conservation and emission reduction.

[0003] The automotive industry and the steel industry are working together to reduce carbon emissions. European automobile companies are moving upstream to build low-carbon supply chains and are particularly eager to find suppliers in China. Low-carbon emission smelting has become an external requirement for the transformation of the steel industry.

[0004] Although the domestic green steel market is just getting started, the demand for this type of steel will expand across the entire society and the entire industrial chain. The demand is on the eve of an explosion, and now is an important window to seize the advantageous position in the development of green steel.

[0005] Against this backdrop, Bengang Group has broken through the carbon emission bottleneck encountered by traditional production methods, developed new ways to increase benefits, and used low-carbon emission automotive steel as an embedding point to find a "solution" to transform towards green and low-carbon development. Summary of the invention

[0006] The present invention provides a smelting method for ultra-low carbon automotive steel with reduced carbon emissions. The method uses semi-steel mixed with electric furnace molten steel (total amount 30% to 70%) + blast furnace molten iron (total amount 70% to 30%) to perform converter blowing, which not only ensures the thermal balance of the smelting process, but also effectively reduces the carbon emissions of the entire production line production process.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A smelting method for ultra-low carbon automotive steel with reduced carbon emissions, the method using semi-steel mixed with 30wt% to 70wt% of electric furnace molten steel and 70wt% to 30wt% of blast furnace molten iron to perform converter blowing, the converter blowing comprising molten iron pretreatment, converter smelting, LF furnace refining, RH operation, and continuous casting.

[0009] The tapping temperature of the blast furnace molten iron is ≥1490°C; the chemical composition of the molten iron is calculated by weight percentage: C: 3.9% to 4.5%, Si: 0.30% to 0.60%, P≤0.09%, S≤0.04%, and the rest is Fe and unavoidable impurities. The tapping amount is 30% to 70% of the effective volume of the torpedo tank.

[0010] The electric furnace steelmaking includes electric furnace smelting and LF operation: the electric furnace smelting adopts all scrap steel smelting, and the scrap steel is well classified and managed, and the scrap steel containing special elements (Cu, Ni, Mo, Cr) is not allowed to be used; the smelting cycle is 40-60min; the amount of ingredients added: oxygen consumption 21-23Nm 3 / t, foaming agent 17-20kg / t, lime 40-42kg / t, magnesite 25-26kg / t, aluminum wire segment 1.0-1.1kg / t, ladle ash 2.0-2.1kg / t, ferrosilicon 1.0-1.1kg / t. Steel-making conditions are: [O]≤600ppm, [C]≥0.10%, [P]≤0.050%, [S]≤0.040%, residual [Ni+Cu]≤0.09%, [Cr]≤0.08%, [N]≤0.008%, and steel-making temperature is 1600-1630℃;

[0011] During the whole process of LF operation, argon is blown and stirred at the bottom of the ladle. Large argon stirring and heating are not allowed. The slag color must turn white after the total power supply time is ≥20min; the amount of alloy and auxiliary materials added per ton of steel: lime 60-62kg / t, aluminum wire segment 0.8-1.0kg / t, ferrosilicon 0.8-1.0kg / t, silicon carbide 1.0-1.1kg / t. The chemical composition of the molten steel after the LF furnace is calculated by weight percentage: C: 0.9%-1.0%, Si: 0.15%-0.25%, P≤0.013%, S≤0.025%, Cr≤0.15%, Ni≤0.05%, Cu≤0.08%, and the rest are Fe and unavoidable impurities; the molten steel temperature is controlled at ≥1640℃.

[0012] After LF operation, the steel is folded into a torpedo tank filled with molten iron from a blast furnace. In order to reduce the temperature drop of the steel in the torpedo tank, the folding cycle of a single package is controlled to be ≤10min. After the folding is completed, carbonized rice husks are added to the torpedo tank to ensure the covering effect. After mixing, the temperature of the semi-steel is ≥1390℃.

[0013] The molten iron pretreatment comprises: adding 1.4-1.5 kg / t of lime and 0.23-0.24 kg / t of magnesium powder; the slag removal amount is 11-12 kg / t; the treatment time is 40-50 min, and the pretreatment blowing time is 7-9 min.

[0014] The converter smelting cycle is 20-30 minutes, the blowing duration is 8-10 minutes, the final carbon is 0.05wt%-0.06wt%, the final oxygen is 400-500ppm, the final temperature is 1625-1650℃, and the oxygen consumption per ton of steel is 32-33m 3 / t, add: active lime 23-24kg / t, dolomite 11-12kg / t, limestone 23-24kg / t, sinter 3.5-4.5kg / t. Converter re-blowing: Bottom blowing system blows argon throughout the whole process.

[0015] The LF furnace refining has an operation time of 35 to 55 minutes, a temperature before treatment of 1570 to 1580°C, an argon stop temperature of 1635 to 1645°C, a temperature leaving the station of 1625 to 1635°C, and an end point oxygen of 500 to 540 ppm, ensuring online baking before steelmaking, and adopting submerged arc operation to prevent nitrogen increase.

[0016] The RH operation described: operation time ≤45min, temperature before treatment ≥1620℃, temperature leaving the station ≥1590℃, oxygen content entering the station is 490-530ppm, decarburization time is 18-20min, net circulation time is 6-8min, vacuum degree ≤50Pa; alloy addition amount is: aluminum particle consumption 0.94-1.22kg / t, low carbon ferromanganese 0.8-1.1kg / t, ferrotitanium 1.2-1.4kg / t.

[0017] The continuous casting: the casting cycle is 60-70 minutes, the casting temperature is 1560-1570℃, and the pulling speed is 1.1-1.2m / min. The sealing of the long water nozzle and the argon flow control must be carried out in accordance with the current regulations. The cover of the middle ladle and the ladle body are required to be sealed, and the holes on the cover except the pouring hole are required to be covered.

[0018] The chemical composition of the automobile steel is calculated by weight percentage as follows: C<0.05%, Si≤0.03%, Mn: 0.09%~0.17%, P≤0.013%, S≤0.012%, Alt0.02%~0.05%, Ti0.06%~0.095%, Cr+Ni+Cu≤0.20%, N≤0.003%, and the rest is Fe and unavoidable impurities.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1) This method uses a mixture of electric furnace molten steel and blast furnace molten iron for converter blowing, which not only ensures the heat source required for converter smelting, but also effectively reduces carbon emissions generated during the blowing process.

[0021] In order to achieve the above-mentioned purpose of the invention, the present invention provides a smelting process path for ultra-low carbon automotive steel with reduced carbon emissions, the specific steps are: (30wt%~70wt% of molten steel in electric furnace + 70wt%~30wt% of molten iron in blast furnace) → converter steelmaking → LF → RH → continuous casting ingot meets the requirements of ultra-low carbon automotive steel composition, cleanliness and other indicators.

[0022] 2) The “semi-steel” process reduces the carbon content of the charge entering the converter, effectively reducing carbon oxide emissions.

[0023] 3) The non-metallic inclusions and performance of the finished product meet the requirements of ultra-low carbon automotive steel products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0025] The specific implementation modes of the present invention are further described below in conjunction with the embodiments.

[0026] Embodiment 1:

[0027] 1. Process route: A smelting method for ultra-low carbon automotive steel with reduced carbon emissions. This method uses semi-steel mixed with electric furnace molten steel (total 50%) + blast furnace molten iron (total 50%) for converter blowing, which not only ensures the thermal balance of the smelting process, but also effectively reduces the carbon emissions of the entire production line. Converter blowing includes molten iron pretreatment, converter smelting, LF furnace refining, RH operation, and continuous casting.

[0028] 2. Chemical composition: The chemical composition of automobile steel is calculated by weight percentage: C: 0.0017%, Si: 0.001%, Mn: 0.10%, P: 0.003%, S: 0.003%, Alt: 0.029%, Ti: 0.075%, Cr+Ni+Cu: 0.033%, N: 0.0019%, and the rest is Fe and unavoidable impurities.

[0029] 3. Blast furnace molten iron + electric furnace process:

[0030] 1) Blast furnace molten iron: molten iron requirements: C: 4.22%, Si: 0.40%, P: 0.074%, S: 0.03, temperature 1520℃, and the iron output is 50% of the effective volume of the torpedo tank.

[0031] 2) Electric furnace smelting: Ingredients: Use all scrap steel for smelting, and do a good job of classification and management of scrap steel. Scrap steel containing special elements (Cu, Ni, Mo, Cr) is not allowed to be used; smelting cycle 50min; amount of oxygen added per ton of steel: 22Nm 3 / t, foaming agent 18Kg / t, lime 40kg / t, magnesite 25kg / t, aluminum wire segment 1.0kg / t, ladle ash 2.0kg / t, ferrosilicon 1.0kg / t.

[0032] Steel tapping conditions: oxygen content 550ppm, [C] 0.12%, [P] 0.032%, [S] 0.03%, residual [Ni+Cu] 0.06%, [Cr] 0.06%, [N] 0.005%, and steel tapping temperature is 1614℃.

[0033] 3) LF operation: The ladle bottom is blown with argon for stirring during the whole process. Large argon stirring and heating are not allowed. The slag color must turn white after 40 minutes of operation. The amount of alloy and auxiliary materials added per ton of steel: lime 60Kg / t, aluminum wire segment 0.9Kg / t, ferrosilicon 0.9Kg / t, silicon carbide 1.0Kg / t. The composition of molten steel after LF furnace is calculated by weight percentage: C: 0.94%, Si: 0.20%, P: 0.010%, S: 0.015%, Cr: 0.13%, Ni: 0.04%, Cu: 0.06%, and the rest is Fe and unavoidable impurities; the molten steel temperature is controlled at 1650℃.

[0034] 4) Operation of folding into torpedo tank: In order to reduce the temperature drop of steel in torpedo tank, the folding cycle of single package is controlled at 7 minutes; after the folding is completed, carbonized rice husk is added into the torpedo tank to ensure the covering effect, and the semi-steel temperature after mixing is 1408℃.

[0035] 4. Converter process:

[0036] 1) Hot metal pretreatment:

[0037] The molten iron requires pretreatment, lime 1.4kg / t, magnesium powder 0.23kg / t, slag removal amount 11kg / t, processing time 45min, pretreatment blowing time 8min.

[0038] 2) Converter smelting:

[0039] The smelting cycle is 26 minutes, the blowing duration is 9 minutes, the final carbon is 0.05wt%, the final oxygen is 482ppm, the final temperature is 1633℃, and the oxygen consumption per ton of steel is 32.7m 3 / t, active lime 24kg / t, dolomite 12kg / t, limestone 23kg / t, sintered ore 4.1kg / t. Converter re-blowing: Bottom blowing system is argon-blown throughout the whole process.

[0040] 3) LF refining: operation time 42min, temperature before treatment 1574℃, argon stop temperature 1637℃, leaving station temperature 1628℃, final oxygen 508ppm.

[0041] 4) RH operation: operation time 40min, temperature before treatment 1622℃, temperature leaving the station 1591℃, oxygen content entering the station 498ppm, decarburization time 18min, net cycle time 8min, vacuum degree 42Pa, aluminum particle consumption 1.14kg / t, low carbon ferromanganese 0.9kg / t, ferrotitanium 1.2kg / t.

[0042] 5) Continuous casting: Casting cycle 63min, casting temperature 1567℃, pulling speed 1.1m / min, the long water nozzle sealing and argon flow control must be carried out in accordance with the current regulations; the ladle cover and the ladle body are required to be sealed, and all holes on the ladle cover except the pouring holes are required to be covered.

[0043] Embodiment 2:

[0044] 1. Process route: A smelting method for ultra-low carbon automotive steel with reduced carbon emissions. This method uses semi-steel mixed with electric furnace molten steel (total 55%) + blast furnace molten iron (total 45%) for converter blowing, which not only ensures the thermal balance of the smelting process, but also effectively reduces the carbon emissions of the entire production line. Converter blowing includes molten iron pretreatment, converter smelting, LF furnace refining, RH operation, and continuous casting.

[0045] 2. Chemical composition: The chemical composition of automobile steel is calculated by weight as follows: C: 0.02%, Si: 0.03%, Mn: 0.16%, P: 0.008%, S: 0.007%, Alt: 0.042%, Ti: 0.077%, Cr+Ni+Cu: 0.061%, N: 0.0028%, and the rest is Fe and unavoidable impurities.

[0046] 3. Blast furnace molten iron + electric furnace process:

[0047] 1) Blast furnace molten iron: The chemical composition of the molten iron is as follows by weight: C: 3.95%, Si: 0.40%, P: 0.09%, S: 0.03%, and the rest is Fe and unavoidable impurities; the temperature is 1500°C, and the iron output is 45% of the effective volume of the torpedo tank.

[0048] 2) Electric furnace smelting: Ingredients: Use all scrap steel for smelting, and do a good job of classification and management of scrap steel. Scrap steel containing special elements (Cu, Ni, Mo, Cr) is not allowed to be used; smelting cycle 52min; amount of oxygen added per ton of steel: 21Nm 3 / t, foaming agent 18Kg / t, lime 40Kg / t, magnesite 25Kg / t, aluminum wire segment 1.0Kg / t, ladle ash 2.0Kg / t, ferrosilicon 1.0Kg / t.

[0049] Steel tapping conditions: oxygen content 514ppm, [C] 0.14%, [P] 0.028%, [S] 0.027%, residual [Ni+Cu] 0.07%, [Cr] 0.06%, [N] 0.0066%, and steel tapping temperature is 1608℃.

[0050] 3) LF operation: The ladle bottom is blown with argon for stirring during the whole process. Large argon stirring is not allowed to heat up. The slag color must turn white after a total power supply time of 24 minutes. The amount of alloy and auxiliary materials added per ton of steel: lime 61Kg / t, aluminum wire segment 0.9Kg / t, ferrosilicon 0.9Kg / t, silicon carbide 1.0Kg / t. The chemical composition of the molten steel after the LF furnace is calculated by weight percentage: C: 0.9%, Si: 0.22%, P: 0.010%, S: 0.011%, Cr: 0.10%, Ni: 0.03%, Cu: 0.04%, and the rest is Fe and unavoidable impurities; the molten steel temperature is controlled at 1650℃.

[0051] 4) Operation of folding into torpedo tank: In order to reduce the temperature drop of steel in torpedo tank, the folding cycle of single package is controlled at 8 minutes; after the folding is completed, carbonized rice husk is added into the torpedo tank to ensure the covering effect, and the semi-steel temperature after mixing is 1400℃.

[0052] 4. Converter process design:

[0053] 1) Hot metal pretreatment: Hot metal requires pretreatment, lime 1.4kg / t, magnesium powder 0.23kg / t, slag removal amount 12kg / t, total treatment time 44min, pretreatment blowing time 8min.

[0054] 2) Converter smelting: smelting cycle 25min, blowing duration 9min, end point carbon 0.06%, end point oxygen 408ppm, end point temperature 1641℃, oxygen consumption per ton of steel 32m 3 / t, active lime 23kg / t, dolomite 11kg / t, limestone 23kg / t, sinter 3.7kg / t. Converter re-blowing: Bottom blowing system is argon-blown throughout the whole process.

[0055] 3) LF refining: operation time 48min, temperature before treatment 1573℃, argon stop temperature 1639℃, leaving station temperature 1632℃, final oxygen 514ppm, ensure online baking before steelmaking, adopt submerged arc operation to prevent nitrogen increase.

[0056] 4) RH operation: operation time 38min, temperature before treatment 1624℃, temperature leaving the station 1593℃, oxygen content entering the station 511ppm, decarburization time 18min, net cycle time 6min, vacuum degree 42Pa, aluminum particle consumption 1.04kg / t, low carbon ferromanganese 0.9Kg / t, ferrotitanium 1.2kg / t.

[0057] 5) Continuous casting: Casting cycle 65min, casting temperature 1565℃, pulling speed 1.2m / min, the long water nozzle sealing and argon flow control must be carried out in accordance with the current regulations; the ladle cover and the ladle body are required to be sealed, and all holes on the ladle cover except the pouring holes are required to be covered.

[0058] Embodiment 3:

[0059] 1. Process route: A smelting method for ultra-low carbon automotive steel that reduces carbon emissions. This method uses a mixture of electric furnace molten steel (total 48%) and blast furnace molten iron (total 52%) to perform converter blowing, which not only ensures the thermal balance of the smelting process, but also effectively reduces the carbon emissions of the entire production line.

[0060] 2. Chemical composition: The chemical composition of automobile steel is calculated by weight percentage: C: 0.0013%, Si: 0.001%, Mn: 0.11%, P: 0.005%, S: 0.004%, Alt: 0.037%, Ti: 0.078%, Cr+Ni+Cu≤0.052%, N: 0.0024%, and the rest is Fe and unavoidable impurities.

[0061] 3. Electric furnace process:

[0062] 1) Blast furnace molten iron: The chemical composition of molten iron is as follows by weight: C: 4.35%, Si: 0.42%, P: 0.082%, S: 0.03%, and the rest is Fe and unavoidable impurities; the furnace temperature is 1518°C, and the iron output is 50% of the effective volume of the torpedo tank.

[0063] 2) Electric furnace smelting: Ingredients: Use all scrap steel for smelting, and do a good job of classification and management of scrap steel. Scrap steel containing special elements (Cu, Ni, Mo, Cr) is not allowed to be used; smelting cycle 50min; amount of oxygen added per ton of steel: 22Nm 3 / t, foaming agent 18kg / t, lime 40kg / t, magnesite 25kg / t, aluminum wire segment 1.0kg / t, ladle ash 2.0kg / t, ferrosilicon 1.0kg / t.

[0064] Steel tapping conditions: oxygen content 545ppm, [C] 0.12%, [P] 0.032%, [S] 0.028%, residual [Ni+Cu] 0.062%, [Cr] 0.06%, [N] 0.005%, temperature: 1620℃.

[0065] 3) LF operation: The ladle is stirred with argon blowing at the bottom during the whole process. Large argon stirring and heating are not allowed. The slag color must turn white after 40 minutes of operation. The amount of alloy and auxiliary materials added per ton of steel: lime 60Kg / t, aluminum wire segment 0.9Kg / t, ferrosilicon 0.9Kg / t, silicon carbide 1.0Kg / t. The chemical composition of the molten steel after the LF furnace is calculated by weight percentage: C: 0.96%, Si: 0.22%, P: 0.010%, S: 0.012%, Cr: 0.12%, Ni: 0.04%, Cu: 0.05%, and the rest is Fe and unavoidable impurities; the molten steel temperature is controlled at 1650℃.

[0066] 4) Operation of folding into torpedo tank: In order to reduce the temperature drop of steel in torpedo tank, the folding cycle of single package is controlled at 7 minutes; after the folding is completed, carbonized rice husk is added into the torpedo tank to ensure the covering effect, and the semi-steel temperature after mixing is 1412℃.

[0067] 4. Converter process:

[0068] 1) Hot metal pretreatment: Hot metal requires pretreatment, lime 1.4kg / t, magnesium powder 0.23kg / t, slag removal amount 11kg / t, treatment time 46min, pretreatment blowing time 8min.

[0069] 2) Converter smelting: smelting cycle 27min, blowing duration 9min, end point carbon 0.06%, end point oxygen 411ppm, end point temperature 1637℃, oxygen consumption per ton of steel 32.8m 3 / t, active lime 24kg / t, dolomite 12kg / t, limestone 23kg / t, sintered ore 4.0kg / t. Converter re-blowing: Bottom blowing system is argon-blown throughout the whole process.

[0070] 3) LF refining: operation time 41min, temperature before treatment 1578℃, argon stop temperature 1640℃, leaving station temperature 1632℃, final oxygen 502ppm.

[0071] 4) RH operation: operation time 40min, temperature before treatment 1624℃, temperature leaving the station 1601℃, oxygen content entering the station 505ppm, decarburization time 19min, net cycle time 8min, vacuum degree 46Pa, aluminum particle consumption 0.98kg / t, low carbon ferromanganese 0.9kg / t, ferrotitanium 1.2kg / t.

[0072] 5) Continuous casting: Casting cycle 64min, casting temperature 1569℃, pulling speed 1.2m / min, the long water nozzle sealing and argon flow control must be carried out in accordance with the current regulations; the ladle cover and the ladle body are required to be sealed, and all holes on the ladle cover except the pouring holes are required to be covered.

[0073] The standard requirements for mechanical properties are shown in Table 1.

[0074] Table 1:

[0075]

[0076] The test results of the embodiment are shown in Table 2.

[0077] Table 2:

[0078]

[0079] Samples were taken at the head, middle and tail of the steel plates of the products of Examples 1-3 for inspection. The inspection performance of Examples 1-3 met the standard requirements, so this method is feasible.

Claims

1. A method for smelting ultra-low carbon automotive steel with reduced carbon emissions, characterized in that: The method is to use semi-steel mixed with 30wt% to 70wt% of electric furnace molten steel and 70wt% to 30wt% of blast furnace molten iron to perform converter blowing, wherein the converter blowing includes molten iron pretreatment, converter smelting, LF furnace refining, RH operation and continuous casting.

2. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The tapping temperature of the blast furnace molten iron is ≥1490°C; the chemical composition of the molten iron is as follows by weight percentage: C: 3.9%-4.5%, Si: 0.30%-0.60%, P≤0.09%, S≤0.04%, and the rest is Fe and unavoidable impurities.

3. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The electric furnace molten steel smelting includes electric furnace smelting and LF operation: the electric furnace smelting adopts all scrap steel smelting, and the scrap steel does not contain Cu, Ni, Mo, and Cr; the smelting cycle is 40 to 60 minutes; the steel tapping conditions are: [O]≤600ppm, [C]≥0.10%, [P]≤0.050%, [S]≤0.040%, residual [Ni+Cu]≤0.09%, [Cr]≤0.08%, [N]≤0.008%, and the steel tapping temperature is 1600 to 1630°C; During the whole process of LF operation, argon is blown and stirred at the bottom of the ladle, and the total power supply time is ≥20min. The chemical composition of the molten steel after LF furnace is as follows by weight: C: 0.9%~1.0%, Si: 0.15%~0.25%, P≤0.013%, S≤0.025%, Cr≤0.15%, Ni≤0.05%, Cu≤0.08%, and the rest is Fe and unavoidable impurities; the molten steel temperature is controlled at ≥1640℃.

4. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 3, characterized in that: After LF operation, the molten iron is folded into a torpedo can filled with blast furnace molten iron, and the folding cycle of a single bag is controlled to be ≤10min; after the folding is completed, carbonized rice husks are added to the torpedo can for covering, and the semi-steel temperature after mixing is ≥1390℃.

5. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The molten iron pretreatment comprises: adding 1.4-1.5 kg / t of lime and 0.23-0.24 kg / t of magnesium powder; the slag removal amount is 11-12 kg / t; the treatment time is 40-50 min, and the pretreatment blowing time is 7-9 min.

6. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The converter smelting cycle is 20-30 minutes, the blowing duration is 8-10 minutes, the end point carbon is 0.05wt%-0.06wt%, the end point oxygen is 400-500ppm, and the end point temperature is 1625-1650℃.

7. The smelting method of ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The LF furnace refining has an operation time of 35 to 55 minutes, a temperature before treatment of 1570 to 1580°C, an argon stop temperature of 1635 to 1645°C, a temperature leaving the station of 1625 to 1635°C, and an end point oxygen of 500 to 540 ppm.

8. The method for smelting ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The RH operation described: operation time ≤45min, temperature before treatment ≥1620℃, temperature leaving the station ≥1590℃, oxygen content entering the station is 490-530ppm, decarburization time is 18-20min, net circulation time is 6-8min, vacuum degree ≤50Pa; alloy addition amount is: aluminum particle consumption 0.94-1.22kg / t, low carbon ferromanganese 0.8-1.1kg / t, ferrotitanium 1.2-1.4kg / t.

9. The method for smelting ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The continuous casting has a casting cycle of 60 to 70 minutes, a casting temperature of 1560 to 1570° C., and a pulling speed of 1.1 to 1.2 m / min.

10. The method for smelting ultra-low carbon automobile steel with reduced carbon emissions according to claim 1, characterized in that: The chemical composition of the automobile steel is calculated by weight percentage as follows: C < 0.05%, Si ≤ 0.03%, Mn: 0.09% to 0.17%, P ≤ 0.013%, S ≤ 0.012%, Alt 0.02% to 0.05%, Ti 0.06% to 0.095%, Cr+Ni+Cu ≤ 0.20%, N ≤ 0.003%, and the rest is Fe and unavoidable impurities.

Images