CN112430773A - Preparation method and application of steel for battery case - Google Patents
Preparation method and application of steel for battery case Download PDFInfo
- Publication number
- CN112430773A CN112430773A CN202011332918.8A CN202011332918A CN112430773A CN 112430773 A CN112430773 A CN 112430773A CN 202011332918 A CN202011332918 A CN 202011332918A CN 112430773 A CN112430773 A CN 112430773A
- Authority
- CN
- China
- Prior art keywords
- steel
- less
- molten steel
- percent
- equal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/116—Refining the metal
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/02—Dephosphorising or desulfurising
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/35—Blowing from above and through the bath
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/10—Handling in a vacuum
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
Abstract
The invention particularly relates to a preparation method and application of steel for a battery case, and belongs to the technical field of ferrous metallurgy. The method comprises the following steps: performing KR desulfurization pretreatment on molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent; carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorized molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is less than or equal to 0.04 percent, and the temperature of the dephosphorized molten steel is 1300-1400 ℃; carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburized molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is less than 0.015 percent and S is less than 0.0080 percent; the dephosphorization converter smelting and the decarburization converter smelting adopt a duplex converter smelting process; and tapping the decarburized molten steel at the temperature of 1670-1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel. Feeding rare earth filaments into the crystallizer. By adopting the method, the total oxygen mass fraction in the steel for the battery case is less than 0.0020 percent, the length-width ratio of the inclusion is less than or equal to 2, and the maximum length of the inclusion is less than 30 mu m.
Description
Technical Field
The invention belongs to the technical field of ferrous metallurgy, and particularly relates to a preparation method and application of steel for a battery case.
Background
In the preparation process of the battery case, the steel needs to be stretched and thinned for multiple times, and the case body can be thinned to 0.15-0.18 mm. This places very stringent requirements on cleanliness, surface quality, mechanical properties and thickness tolerances of the steels for battery cases.
Related patents exist before the steel for the battery case, for example, the patent of Jinggujiahong of Japanese steel pipe company in 1997 mainly focuses on the content control of key elements in steel grades, and the S of the steel plate is controlled to be 0.005-0.015 percent; 0, 0-0.0025%; b, 0.0005 to 0.0015 percent; [ S/10+0] < 0.0035%, B/N is more than or equal to 0.2 and less than or equal to 1.0. The patent of Bambijun in 2005 of Bao Steel proposes the control points of the hot rolling and cold rolling processes for steel for battery cases with excellent planar isotropy. The key process control of steel-making and hot-rolling processes was proposed in 2016 of Tangshan Li Meng. The molten iron desulphurization adopts the blowing of lime and magnesium powder, the S content of the molten iron fed into the converter is less than or equal to 0.003 percent, and the converter smelting adopts the combined blowing of a single converter. The target steel grade of the patent 'steel for a new energy automobile battery case and a production method thereof by rapid and thinning stamping processing' in 2018 of Tangshan Li Mengsu et al is ultra-low carbon steel.
Disclosure of Invention
In view of the above problems, the present invention has been made in order to provide a method of manufacturing and use of steel for battery cases that overcomes or at least partially solves the above problems.
The embodiment of the invention provides a preparation method of steel for a battery case, which comprises the following steps:
performing KR desulfurization pretreatment on molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent;
carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorized molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is less than or equal to 0.04 percent, and the temperature of the dephosphorized molten steel is 1300-1400 ℃;
carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburized molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is less than 0.015 percent and S is less than 0.0080 percent; the dephosphorization converter smelting and the decarburization converter smelting adopt a duplex converter smelting process;
tapping the decarburized molten steel at the temperature of 1670-1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel;
and continuously casting the refined molten steel to obtain a steel casting blank for the battery case, wherein the chemical components of the steel casting blank for the battery case meet the following requirements: c: 0.01-0.15%, Si: 0-0.04%, Mn: 0.05-1%, P is less than 0.016%, S is less than 0.010%, Alt: 0.015-0.1%.
Optionally, in the continuous casting, the casting temperature is 1540-1570 ℃, the pulling speed is less than or equal to 1.5m/min, the liquid level fluctuation is less than or equal to +/-5 mm, and the crystallizer feeds 50-300 g/ton of steel rare earth wires.
Optionally, the continuous casting adopts an argon sealing and full-protection casting process.
Optionally, in the KR desulfurization pretreatment, the desulfurizing agent is at least one of CaO and CaO-CaF2The amount of the desulfurizer is 0.1-0.3kg per ton of steel.
Optionally, in the smelting of the dephosphorization converter, the dephosphorization agent is at least one of CaO and CaO-CaF2The dosage of the dephosphorizing agent is 20-50kg per ton of steel.
Optionally, in the smelting of the carbon converter, the decarburization is top blowing oxygen, and the oxygen supply intensity is 2-6 Nm3/t·min。
Optionally, after-blowing is not performed in the smelting process of the decarburization converter, and front and rear sliding plates are used for pushing off slag in the tapping process.
Optionally, in the RH refining, the pressure of vacuum treatment is 6-30MPa, the time of vacuum treatment is not less than 15min, and the time of pure degassing is not less than 6 min.
Optionally, carry out steel composition adjustment in the RH refining process, in the steel composition adjustment, use medium carbon ferromanganese to transfer Mn, the aluminium grain transfers Al, and silicon iron transfers Si.
Based on the same inventive concept, the invention also provides application of the steel for the battery case, and the steel for the battery case is used as the steel material for preparing the battery case.
One or more technical solutions in the embodiments of the present invention have at least the following technical effects or advantages:
the preparation method of the steel for the battery case provided by the embodiment of the invention comprises the following steps: performing KR desulfurization pretreatment on molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent; carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorized molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is less than or equal to 0.04 percent, and the temperature of the dephosphorized molten steel is 1300-1400 ℃; carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburized molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is less than 0.015 percent and S is less than 0.0080 percent; the dephosphorization converter smelting and the decarburization converter smelting adopt a duplex converter smelting process; tapping the decarburized molten steel at the temperature of 1670-1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel; and continuously casting the refined molten steel to obtain a steel casting blank for the battery case, wherein the chemical components of the steel casting blank for the battery case meet the following requirements: c: 0.01-0.15%, Si: 0-0.04%, Mn: 0.05-1%, P is less than 0.016%, S is less than 0.010%, Alt: 0.015-0.1%.
The quality problem which is most likely to occur in the process of stretching and thinning the battery shell for multiple times in the preparation process is the blister defect. The occurrence of blisters is mainly related to inclusions. The principle of the scheme is as follows: controlling S in the molten iron to be less than or equal to 0.0015 percent through KR desulfurization pretreatment; p of the dephosphorization converter is controlled to be less than 0.015 percent under the conditions of temperature, good thermodynamic conditions of dephosphorization slag systems and good kinetic conditions of top-bottom combined blowing and stirring. The decarburization converter adjusts the content of C to 0.01 to 0.15% of an appropriate composition. The RH vacuum refining performs collision removal of inclusions using good kinetic conditions. The continuous casting rare earth feeding wire carries out final modification on the impurities.
By adopting the preparation method of the steel for the battery case, provided by the embodiment of the invention, the number density of inclusion inclusions in the steel for the battery case is less than or equal to 5/mm2(ii) a The grade of the inclusion is less than or equal to 1.0 grade; the aspect ratio is substantially 2 (see FIG. 2).
The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a flowchart of a method for manufacturing steel for battery cases in examples of the present invention;
FIG. 2 is an electron microscope image of the morphology of inclusions in the steel for battery cases prepared in example 1 of the present invention.
Detailed Description
The present invention will be described in detail below with reference to specific embodiments and examples, and the advantages and various effects of the present invention will be more clearly apparent therefrom. It will be understood by those skilled in the art that these specific embodiments and examples are for the purpose of illustrating the invention and are not to be construed as limiting the invention.
Throughout the specification, unless otherwise specifically noted, terms used herein should be understood as having meanings as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. If there is a conflict, the present specification will control.
Unless otherwise specifically stated, various raw materials, reagents, instruments, equipment and the like used in the present invention are commercially available or can be prepared by existing methods.
In order to solve the technical problems, the general idea of the embodiment of the present application is as follows
In one aspect, as shown in fig. 1, an embodiment of the present invention provides a method for preparing steel for a battery case, the method including:
s1, carrying out KR desulfurization pretreatment on the molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent;
the reason and the beneficial effect that the S content in the desulfurized molten iron is controlled to be less than or equal to 0.0015 percent are that the MnS inclusions are too much due to too high sulfur content and the MnS is not extended and cracked in the multi-pass stretching process because the rare earth denaturation treatment is incomplete in the later period are avoided; the reason for controlling the slag skimming rate to be more than or equal to 95 percent and the beneficial effect are that when the slag skimming rate is too low, the sulfur in the slag can enter the molten steel again, so that the obvious sulfur increase is caused;
the desulfurization can be carried out in the following manner: the desulfurizer is at least one of CaO and CaO-CaF2The amount of the desulfurizer is 0.1-0.3kg per ton of steel, and finally the S in the desulfurized molten iron is less than or equal to 0.0015 percent; the reason and the beneficial effect of selecting the desulfurizing agent are that the cost is advantageous under the condition of ensuring the desulfurization rate; the reason and the beneficial effect of controlling the dosage of the desulfurizer to be 0.1-0.3 kg/ton steel are that the KR end point S can be controlled to be less than or equal to 0.0015 percent in the addition amount range.
S2, carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorization molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is less than or equal to 0.04 percent, and the temperature of the dephosphorized molten steel is 1300-1400 ℃;
the reason and the beneficial effect that P in the dephosphorized molten steel is controlled to be less than or equal to 0.04 percent are to improve the hit rate of the end point P which is less than 0.016 percent;
the reason and the beneficial effect that the temperature of the dephosphorized molten steel is controlled to be 1300-1400 ℃, are that the dephosphorization is facilitated at low temperature, but the temperature can not be too low in consideration of slagging and dynamic factors;
dephosphorization can be carried out in the following way: the dephosphorizing agent is at least one of CaO and CaO-CaF2The dosage of the dephosphorizing agent is 20-50kg per ton of steel; the dephosphorization agent is selected because and has the advantages that the cost of the lime dephosphorization agent is lower than that of metal dephosphorization agents such as Ca, CaSi and the like; the reason and the beneficial effect that the dosage of the dephosphorizing agent is controlled to be 20-50 kg/ton steel are that the dosage of the dephosphorizing agent can control the P terminal point P of the dephosphorizing furnace to be less than or equal to 0.04 percent.
S3, carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburization molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is less than 0.015 percent and S is less than 0.0080 percent; the dephosphorization converter smelting and the decarburization converter smelting adopt a duplex converter smelting process;
the reason and the beneficial effect that the P content in the decarburized steel water is controlled to be less than 0.015 percent and the S content in the decarburized steel water is controlled to be less than 0.0080 percent are that the P and S contents in the molten steel are ensured to be within a target range;
the reason why the post-blowing is not carried out in the smelting process of the decarburization converter is to prevent the molten steel from being excessively oxidized and the content of inclusions from exceeding the standard.
S4, tapping the decarburized molten steel at the temperature of 1670-1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel;
the reason and the beneficial effect that the decarburized molten steel is controlled to be tapped at the temperature of 1670-1700 ℃ are that the RH circulation temperature drop is ensured;
the reason for adopting the front and rear sliding plates to block the slag in the tapping process is to prevent the slag from entering the refining furnace to cause rephosphorization and resulfurization;
in RH refining, the pressure of vacuum treatment is controlled to be 6-30MPa, and the reason why the time of vacuum treatment is more than or equal to 15min is to ensure the circular removal of impurities;
the reason why the pure degassing time is more than or equal to 6min is to remove H in the molten steel;
carry out the steel composition adjustment among the RH refining process, in the steel composition adjustment, use medium carbon ferromanganese to transfer Mn, the aluminium grain transfers Al, and the silicon iron transfers Si's reason and beneficial effect to finely tune the alloy.
S5, continuously casting the refined molten steel to obtain a steel casting blank for the battery case, wherein the chemical components of the steel casting blank for the battery case meet the following requirements: c: 0.01-0.15%, Si: 0-0.04%, Mn: 0.05-1%, P is less than 0.016%, S is less than 0.010%, Alt: 0.015-0.1%.
In continuous casting, the reason and the beneficial effect that the pouring temperature is controlled to be 1540-1570 ℃ are that the smooth process of the continuous casting process is ensured;
the reason and the beneficial effect that the pulling speed is controlled to be less than or equal to 1.5m/min are that slag entrapment caused by too high pulling speed is prevented;
in the liquid level fluctuation is less than or equal to +/-5 mm, "+/-" indicates the range deviating from the target value; the reason for controlling the liquid level fluctuation to be less than or equal to +/-5 mm and the beneficial effect are that the liquid level fluctuation is prevented;
the reason and the beneficial effect that the rare earth wires of 50-300 g/ton steel are fed into the crystallizer are that the impurities in the molten steel are modified;
the reason and the beneficial effect that the argon sealing and full-protection casting process is adopted in the continuous casting are that the secondary oxidation of the molten steel is prevented;
based on the same inventive concept, the invention also provides application of the steel for the battery case, and the steel for the battery case is used as the steel material for preparing the battery case.
The steel for the battery case provided by the embodiment of the invention is used for preparing the battery case, and has the following advantages:
the refining adopts the single-link RH process flow which is short, high in efficiency and low in production cost; the inclusion control effect is good; the cleanliness of the molten steel is high.
The preparation method and application of the steel for battery cases of the present application will be described in detail below with reference to examples, comparative examples, and experimental data.
Example 1
In this example, the chemical composition of the steel for battery cases was as follows by mass:
C：0.07％；Si：0.03％；Mn：0.6％；P：0.015％；S：0.0027％；Al：0.03％。
the preparation method of the steel for the battery case comprises the following steps:
s1, carrying out KR desulfurization pretreatment on the molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent;
the desulfurizer is CaO-CaF2The amount of the desulfurizer is 0.2kg per ton of steel;
s2, carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorization molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is 0.04%, and the temperature of the dephosphorized molten steel is 1350 ℃;
the dephosphorizing agent is CaO, and the dosage of the dephosphorizing agent is 35kg per ton of steel;
s3, carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburization molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is 0.015 percent and S is 0.0030 percent, and after-blowing is not carried out in the smelting process of the decarburization converter;
s4, tapping the decarburized molten steel at 1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel;
and (3) adopting front and rear sliding plates to block slag in the tapping process, and adding 101kg of aluminum particles in the tapping process.
In RH refining, controlling the pressure of vacuum treatment to be 20MPa and the time of vacuum treatment to be 20 min; the pure degassing time is 6 min;
and S5, continuously casting the refined molten steel to obtain a steel casting blank for the battery case.
In continuous casting, the casting temperature is controlled to be 1545 ℃; controlling the constant pulling speed of 1.4 m/min; controlling the liquid level fluctuation to be less than or equal to +/-5 mm;
feeding 300 g/ton steel rare earth wires into a crystallizer; the continuous casting adopts argon sealing and full-protection casting technology.
Example 2
In this example, the chemical composition of the steel for battery cases was as follows by mass:
C：0.05％，Si：0.03％，Mn：1％，P：0.014％，S：0.0019％，Alt：0.03％。
the preparation method of the steel for the battery case comprises the following steps:
s1, carrying out KR desulfurization pretreatment on the molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0010 percent, and the slag removal rate is more than or equal to 95 percent;
the desulfurizer is GaO-CaF2The amount of the desulfurizer is 0.3kg per ton of steel;
s2, carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorization molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: : p is 0.04%, and the temperature of the dephosphorized molten steel is 1350 ℃;
the dephosphorizing agent is CaO, and the dosage of the dephosphorizing agent is 35kg per ton of steel;
s3, carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburization molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is 0.015 percent and S is 0.0030 percent, and after-blowing is not carried out in the smelting process of the decarburization converter;
s4, tapping the decarburized molten steel at 1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel;
and (3) adopting front and rear sliding plates to block slag in the tapping process, and adding 101kg of aluminum particles in the tapping process.
In RH refining, controlling the pressure of vacuum treatment to be 30MPa and the time of vacuum treatment to be 22 min; the pure degassing time is 8 min;
and S5, continuously casting the refined molten steel to obtain a steel casting blank for the battery case.
In continuous casting, the casting temperature is controlled to be 1545 ℃; controlling the constant pulling speed of 1.4 m/min; controlling the liquid level fluctuation to be less than or equal to +/-5 mm;
feeding 200 g/ton of steel rare earth wires into a crystallizer; the continuous casting adopts argon sealing and full-protection casting technology.
Comparative example 1
This example differs from example 1 in that: the chemical components of the steel for the battery case are as follows: c: 0.05%, Si: 0.04%, Mn: 2%, P: 0.020%, S: 0.030%, Alt: 0.03 percent.
C：0.01-0.15％，Si：0-0.04％，Mn：0.05-1％，P＜0.016％，S＜0.010％，Alt：0.015-0.1％。
Comparative example 2
This example differs from example 1 in that: cancellation
And (4) feeding rare earth wires into the crystallizer, and feeding calcium wires after RH refining.
Comparative example 3
This example differs from example 1 in that: the pressure of RH refining vacuum treatment is 20MPa, the vacuum treatment time is 13min, and the pure degassing time is 4 min.
The experimental effect is as follows:
the battery cases obtained in examples 1 to 3 and comparative examples 1 to 6 were examined with steels, and the results are shown in table 1.
TABLE 1 effects of use of examples and comparative examples
| Total oxygen mass fraction | Mass fraction of sulfur | Inclusion rating | |
| Example 1 | 0.0018 | 0.0027 | 1.0 stage |
| Example 2 | 0.0017 | 0.0019 | 1.0 stage |
| Comparative example 1 | 0.0020 | 0.03 | Class A class 4.0 stage |
| Comparative example 2 | 00018 | 0.0020 | Class B class 3.0 stage |
| Comparative example 3 | 0.0029 | 0.0023 | Class B class 2.0 stage |
As can be seen from Table 1, the method of the present invention has the inclusion rating of not more than 1.0; when other methods are adopted, the grades of the four types of inclusions cannot be guaranteed to be less than or equal to 1.0 grade.
Finally, it should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the invention.
It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.
Claims (10)
1. A method for preparing steel for battery cases, which is characterized by comprising the following steps:
performing KR desulfurization pretreatment on molten iron to obtain desulfurized molten iron; according to the mass fraction, the desulfurized molten iron meets the following requirements: s is less than or equal to 0.0015 percent, and the slag removal rate is more than or equal to 95 percent;
carrying out dephosphorization converter smelting on the desulfurized molten iron to obtain dephosphorized molten steel; according to the mass fraction, the dephosphorized molten steel meets the following requirements: p is less than or equal to 0.04 percent, and the temperature of the dephosphorized molten steel is 1300-1400 ℃;
carrying out decarburization converter smelting on the dephosphorized molten steel to obtain decarburized molten steel; according to the mass fraction, the decarburized molten steel satisfies the following conditions: p is less than 0.015 percent and S is less than 0.0080 percent; the dephosphorization converter smelting and the decarburization converter smelting adopt a duplex converter smelting process;
tapping the decarburized molten steel at the temperature of 1670-1700 ℃, and carrying out RH refining after tapping to obtain refined molten steel;
and continuously casting the refined molten steel to obtain a steel casting blank for the battery case, wherein the chemical components of the steel casting blank for the battery case meet the following requirements: c: 0.01-0.15%, Si: 0-0.04%, Mn: 0.05-1%, P is less than 0.016%, S is less than 0.010%, Alt: 0.015-0.1%.
2. The method for preparing the steel for the battery shell according to claim 1, wherein in the continuous casting, the casting temperature is 1540-1570 ℃, the pulling speed is less than or equal to 1.5m/min, the liquid level fluctuation is less than or equal to +/-5 mm, and the crystallizer is fed with 50-300 g/ton of steel of rare earth wires.
3. The method for preparing the steel for the battery case according to the claim 1 or 2, wherein the continuous casting adopts argon sealing and full-protection casting process.
4. The method for preparing steel for battery cases as claimed in claim 1 or 3, wherein in the KR desulfurization pretreatment, the desulfurizing agent is at least one of lime and lime-fluorite, and the amount of the desulfurizing agent is 0.1-0.3kg per ton of steel.
5. The method for preparing the steel for battery cases as claimed in claim 1, wherein the dephosphorizing agent is at least one of CaO and CaO-CaF in the smelting process of the dephosphorizing converter2The dosage of the dephosphorizing agent is 20-50kg per ton of steel.
6. The method for preparing the steel for battery cases as claimed in claim 1, wherein the decarburization comprises top-blowing oxygen in the carbon converter smelting, and the oxygen supply strength is 2-6 Nm3/t·min。
7. The method for preparing the steel for the battery case according to the claim 1 or 6, wherein the post-blowing is not performed during the smelting process of the decarburization converter, and front and rear sliding plates are used for slag blocking during the tapping process.
8. The preparation method of the steel for the battery case according to claim 1, wherein in the RH refining, the pressure of vacuum treatment is 6-30MPa, the time of vacuum treatment is not less than 15min, and the time of pure degassing is not less than 6 min.
9. The method for producing steel for battery cases according to claim 1, wherein steel composition adjustment is performed in the RH refining process, and in the steel composition adjustment, Mn is adjusted using medium carbon ferromanganese, Al is adjusted using aluminum particles, and Si is adjusted using ferrosilicon.
10. Use of the steel for battery cases, produced by the method according to any one of claims 1 to 9, wherein the steel for battery cases is used as a steel material for the production of battery cases.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011332918.8A CN112430773A (en) | 2020-11-23 | 2020-11-23 | Preparation method and application of steel for battery case |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011332918.8A CN112430773A (en) | 2020-11-23 | 2020-11-23 | Preparation method and application of steel for battery case |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112430773A true CN112430773A (en) | 2021-03-02 |
Family
ID=74697468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011332918.8A Pending CN112430773A (en) | 2020-11-23 | 2020-11-23 | Preparation method and application of steel for battery case |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112430773A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113584372A (en) * | 2021-06-21 | 2021-11-02 | 首钢集团有限公司 | Casting blank smelting method for reducing black lines on surface of pickled plate |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103305747A (en) * | 2013-06-26 | 2013-09-18 | 李会民 | Steel bar or steel claw section for electric conduction of electrolytic aluminum and manufacturing method of steel bar or steel claw section |
| CN111647817A (en) * | 2020-06-09 | 2020-09-11 | 首钢集团有限公司 | Billet for wheel steel, preparation method and product thereof |
-
2020
- 2020-11-23 CN CN202011332918.8A patent/CN112430773A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103305747A (en) * | 2013-06-26 | 2013-09-18 | 李会民 | Steel bar or steel claw section for electric conduction of electrolytic aluminum and manufacturing method of steel bar or steel claw section |
| CN111647817A (en) * | 2020-06-09 | 2020-09-11 | 首钢集团有限公司 | Billet for wheel steel, preparation method and product thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113584372A (en) * | 2021-06-21 | 2021-11-02 | 首钢集团有限公司 | Casting blank smelting method for reducing black lines on surface of pickled plate |
| CN113584372B (en) * | 2021-06-21 | 2022-06-21 | 首钢集团有限公司 | Casting blank smelting method for reducing black lines on surface of pickled plate |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111910045B (en) | Smelting method of high-purity austenitic stainless steel | |
| CN105603156A (en) | Production method for IF steel containing ultralow sulfur | |
| CN110983161B (en) | Smelting method for realizing ultrahigh purity of bearing steel by controlling adding time of low-aluminum low-titanium ferrosilicon and combining with tundish electromagnetic stirring | |
| CN109161630B (en) | Smelting method of HIC-resistant pipeline steel | |
| CN115404393A (en) | Production method of rare earth Ce treated 16MnHIC steel blank for flange | |
| CN112430773A (en) | Preparation method and application of steel for battery case | |
| CN108611462B (en) | Method for controlling inclusions in ultra-low carbon steel | |
| CN112322958A (en) | Low-carbon aluminum-containing steel and smelting control method thereof | |
| JP2002266047A (en) | Ductile cast iron pipe and manufacturing method therefor | |
| CN113025781B (en) | Method for producing low-carbon low-silicon ultralow-sulfur steel by adopting LF (ladle furnace) single-link process | |
| CN113234893B (en) | Method for pre-refining molten steel | |
| JP3627755B2 (en) | Method for producing high cleanliness ultra low carbon steel with extremely low S content | |
| CN110621793A (en) | Smelting method of high manganese steel | |
| CN105483504B (en) | The production method of -195 DEG C of ultralow temperature seamless steel tube blank steel | |
| CN112342342B (en) | Smelting method of pipeline steel | |
| JP3172550B2 (en) | Manufacturing method of high cleanliness steel | |
| CN114214481A (en) | Method for reducing nitrogen content in steel | |
| JP2991796B2 (en) | Melting method of thin steel sheet by magnesium deoxidation | |
| CN111575441A (en) | Method for modifying deoxidation products in steel by using furnace slag | |
| CN115287406B (en) | Smelting method for removing inclusions in steel | |
| CN115612912B (en) | Refining method for controlling sulfur of structural steel for aluminum-containing shaft | |
| CN115369308B (en) | Method for producing high-strength IF steel | |
| CN115323249B (en) | Smelting method and container device for steel grade | |
| CN115261564B (en) | Pure iron as non-aluminum deoxidizing material for amorphous soft magnetic thin belt and preparation method thereof | |
| CN116574965B (en) | Method for improving inclusion level of wind power steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210302 |
|
| RJ01 | Rejection of invention patent application after publication |