Wire rod for deep drawing and molten steel smelting method thereof
阅读说明：本技术 深拉拔用盘条及其钢液冶炼方法 (Wire rod for deep drawing and molten steel smelting method thereof ) 是由 邹长东 赵家七 蔡小锋 黄永林 皇祝平 张连兵 于 2019-09-26 设计创作，主要内容包括：本发明揭示了一种深拉拔用盘条及其钢液冶炼方法。所述冶炼方法包括铁水脱硫、炉内初炼、炉外精炼以及夹杂物去除,所述炉内初炼工序的出钢过程中依次加入增碳剂、硅铁和金属锰而不加入其它造渣剂,且出钢结束后扒除出钢钢液表面90％以上的炉渣；所述炉外精炼工序包括：调整钢液的化学成分和温度,向钢液表面加入8～12kg/t的精炼覆盖剂并通电熔化所述精炼覆盖剂,通过软搅拌或真空精炼去除钢液中的夹杂物；在所述去除夹杂物工序中,将炉外精炼的出钢钢液转移至具有电磁感应功能的中间包,在电磁离心力的作用下去除钢液中的夹杂物。基于所述冶炼方法所获得的钢液满足夹杂物尺寸≤25μm、夹杂物中SiO<Sub>2</Sub>组分的含量≥40％,该钢液可加工成用于深拉拔的高洁净度盘条。(The invention discloses a wire rod for deep drawing and a molten steel smelting method thereof. The smelting method comprises molten iron desulphurization, primary smelting in a furnace, external refining and inclusion removal, wherein a recarburizing agent, ferrosilicon and manganese metal are sequentially added in the tapping process of the primary smelting procedure in the furnace without adding other slagging agents, and more than 90% of slag on the surface of the molten steel is removed after tapping; the secondary refining process comprises the following steps: adjusting the chemical components and the temperature of the molten steel, and adding 8-12 kg/t of refining coating to the surface of the molten steelCovering agent and electrifying to melt the refining covering agent, and removing inclusions in the molten steel through soft stirring or vacuum refining; in the inclusion removing step, the molten steel refined outside the furnace is transferred to a tundish having an electromagnetic induction function, and inclusions in the molten steel are removed by an electromagnetic centrifugal force. The molten steel obtained based on the smelting method meets the requirements that the size of the inclusions is less than or equal to 25 mu m and SiO in the inclusions 2 The content of the components is more than or equal to 40 percent, and the molten steel can be processed into high-cleanliness wire rods for deep drawing.)
1. A molten steel smelting method of a wire rod for deep drawing is characterized by comprising molten iron desulphurization, primary smelting in a furnace, refining outside the furnace and inclusion removal which are sequentially carried out, wherein a carburant, ferrosilicon and manganese metal are sequentially added in the tapping process of the primary smelting process in the furnace without adding other slagging agents, and more than 90% of slag on the surface of the tapped molten steel is removed after tapping;
the external refining process comprises the following steps: adjusting the chemical components and the temperature of the molten steel; adding 8-12 kg/t of refining covering agent to the surface of the molten steel, and electrifying to melt the refining covering agent; removing impurities in the molten steel by soft stirring or vacuum refining;
in the inclusion removing step, the molten steel refined outside the furnace is transferred to a tundish having an electromagnetic induction function, and inclusions in the molten steel are removed by an electromagnetic centrifugal force.
2. The method for producing a steel melt for a deep-drawing wire rod according to claim 1, wherein the temperature of the molten steel discharged in the initial melting step in the furnace is controlled to 1680 to 1720 ℃, P is 0.015% or less, and C is 0.3 to 0.7%.
3. The molten steel melting method of a deep drawing wire rod according to claim 1, wherein in the in-furnace primary process, dephosphorization and decarbonization are performed using a converter or an electric furnace before tapping; when a converter is adopted for dephosphorization and decarbonization, the weight of molten iron accounts for more than or equal to 85 percent of the total charging amount; when an electric furnace is adopted for dephosphorization and decarburization, the weight of molten iron accounts for more than or equal to 60 percent of the total charge.
4. The molten steel smelting method of a wire rod for deep drawing according to claim 1, wherein the steps of "adjusting chemical components and temperature of molten steel" and "adding 8 to 12kg/t of refining covering agent to the surface of molten steel and melting the refining covering agent by energization" are performed in an LF refining furnace, and after 8 to 12kg/t of refining covering agent is added to the surface of molten steel, the intensity of argon blown into the bottom of a ladle of the LF refining furnace is controlled to be not more than 0.005Nm3/(t·min)。
5. The molten steel smelting method of a wire rod for deep drawing according to claim 1, wherein in the step of "removing inclusions in molten steel by soft stirring or vacuum refining":
when the inclusion in the molten steel is removed by soft stirring, the ladle bottom argon blowing strength of the LF refining furnace is controlled to be 0.001Nm3/(t·min)～0.005Nm3/(t·min)；
When impurities are removed through vacuum refining in an RH vacuum furnace, treating molten steel for 15-20 minutes in a high vacuum environment with the vacuum degree of a vacuum chamber of the RH vacuum furnace being less than or equal to 1.5 mbar;
when the inclusions are removed through vacuum refining of the VD/VOD vacuum furnace, the molten steel is treated for 20-30 minutes in a high-vacuum environment with the vacuum degree of a vacuum chamber of the VD/VOD vacuum furnace being less than or equal to 1.5 mbar.
6. The molten steel smelting method of a wire rod for deep drawing according to claim 1, wherein the tundish has two electromagnetic induction channels, and in the inclusion removing step, the voltage of the electromagnetic induction coil is controlled to be 200 to 1500V and the frequency is controlled to be 300 to 800 Hz.
7. The molten steel smelting method for a wire rod for deep drawing according to claim 1, wherein the size of inclusions in the molten steel obtained by the smelting method is not more than 25 μm, and the inclusions are not more than 25 μmSiO 22The content of the components is more than or equal to 40 percent.
8. The molten steel smelting method for a wire rod for deep drawing according to claim 7, wherein the molten steel obtained by the smelting method has a CaO component content of 30% or less and Al component content of2O3The content of the components is less than or equal to 10 percent.
9. A wire rod for deep drawing, which is characterized in that the wire rod is processed by molten steel obtained by the smelting method according to any one of claims 1 to 8.
10. The wire rod for deep drawing according to claim 9, wherein the wire rod comprises chemical components in mass percent: c: 0.78% -0.96%, Si: 0.15-0.40%, Mn: 0.30 to 0.60 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, and the balance of Fe and other inevitable impurities.
Technical Field
The invention belongs to the technical field of steel smelting, and relates to a molten steel smelting method of a deep-drawing wire rod and the deep-drawing wire rod processed by the molten steel obtained by the smelting method.
Background
The wire rod for deep drawing is mainly used for rubber framework materials such as steel cords and tire bead steel wires for automobile tires, high-pressure rubber tube steel wires for coal and chemical industries, silicon wafer cutting steel wires in solar photovoltaic industries and the like. The wire rod needs to be deeply drawn in the subsequent processing process, and then further processed by stranding and the like according to the needs. Since the wire rod is repeatedly drawn, bent and twisted during the process, there is a very high demand for the overall quality of the wire rod.
For example, in recent years, weight reduction of automobiles has become a trend of modern world automobile development due to recent environmental protection and energy saving requirements, and steel cords are used as main framework materials in automobile tire meridians, and the weight of automobile tires can be reduced by 10% for every improvement of the strength thereof by one level. In order to obtain the ultra-high strength steel cord, the requirements on the comprehensive quality of the wire rod are more strict, and particularly, the requirements on the size, the number and the deformability of inclusions in the wire rod are more strict.
The size of inclusions in steel is reduced, and the fine dispersion distribution of the inclusions is an effective measure for improving the cleanliness of molten steel and improving the quality of steel cord products; and researches show that the SiO with low melting point2The inclusions are easier to deform in the deep drawing process compared with other high-melting-point inclusions, and the low-melting-point SiO is relatively increased2The inclusion ratio is also an effective measure for improving the quality of the steel cord product.
Disclosure of Invention
The invention aims to provide a molten steel smelting method of a wire rod for deep drawing and the wire rod for deep drawing processed by the molten steel obtained by the smelting method.
In order to achieve one of the above objects, an embodiment of the present invention provides a molten steel smelting method for a deep-drawing wire rod, the smelting method including molten iron desulfurization, primary smelting in a furnace, refining outside the furnace, and inclusion removal performed in this order, wherein a recarburizer, ferrosilicon, and manganese metal are sequentially added during tapping in the primary smelting in the furnace without adding other slag formers, and more than 90% of slag on the surface of the molten steel is removed after tapping;
the external refining process comprises the following steps: adjusting the chemical components and the temperature of the molten steel; adding 8-12 kg/t of refining covering agent to the surface of the molten steel, and electrifying to melt the refining covering agent; removing impurities in the molten steel by soft stirring or vacuum refining;
in the inclusion removing step, the molten steel refined outside the furnace is transferred to a tundish having an electromagnetic induction function, and inclusions in the molten steel are removed by an electromagnetic centrifugal force.
As a further improvement of one embodiment of the invention, the temperature of the molten steel discharged in the primary smelting process in the furnace is controlled to be 1180-1120 ℃, P is less than or equal to 0.015 percent, and C is 0.3-0.1 percent.
As a further improvement of an embodiment of the present invention, in the in-furnace primary smelting step, dephosphorization and decarburization are performed using a converter or an electric furnace before tapping; when a converter is adopted for dephosphorization and decarbonization, the weight of molten iron accounts for more than or equal to 85 percent of the total charging amount; when an electric furnace is adopted for dephosphorization and decarburization, the weight of molten iron accounts for more than or equal to 10 percent of the total loading.
As a further improvement of one embodiment of the invention, the steps of adjusting the chemical components and the temperature of the molten steel and adding 8-12 kg/t of refining covering agent to the surface of the molten steel and electrifying to melt the refining covering agent are carried out in the LF refining furnace, and after 8-12 kg/t of refining covering agent is added to the surface of the molten steel, the intensity of argon blown from the bottom of a ladle of the LF refining furnace is controlled to be less than or equal to 0.005Nm3/(t·min)。
As a further improvement of an embodiment of the present invention, in the step "removing inclusions in molten steel by soft stirring or vacuum refining":
when the inclusion in the molten steel is removed by soft stirring, the ladle bottom argon blowing strength of the LF refining furnace is controlled to be 0.001Nm3/(t·min)～0.005Nm3/(t·min)；
When impurities are removed through vacuum refining in an RH vacuum furnace, treating molten steel for 15-20 minutes in a high vacuum environment with the vacuum degree of a vacuum chamber of the RH vacuum furnace being less than or equal to 1.5 mbar;
when the inclusions are removed through vacuum refining of the VD/VOD vacuum furnace, the molten steel is treated for 20-30 minutes in a high-vacuum environment with the vacuum degree of a vacuum chamber of the VD/VOD vacuum furnace being less than or equal to 1.5 mbar.
In a further improvement of an embodiment of the present invention, the tundish includes two electromagnetic induction channels, and in the step of removing the inclusions, the voltage of the electromagnetic induction coil is controlled to be 200 to 1500V and the frequency is controlled to be 300 to 800 Hz.
As a further improvement of one embodiment of the invention, the size of the inclusion in the molten steel obtained by the smelting method is less than or equal to 25 mu m, and SiO in the inclusion2The content of the components is more than or equal to 40 percent.
As a further improvement of one embodiment of the invention, the molten steel obtained by the smelting method contains 30% or less of CaO component and Al component2O3The content of the components is less than or equal to 10 percent.
In order to achieve one of the above objects, an embodiment of the present invention further provides a wire rod for deep drawing, which is processed from the molten steel obtained by the smelting method according to any one of the above embodiments.
As a further improvement of an embodiment of the present invention, the chemical components of the wire rod comprise, by mass: c: 0.18% -0.91%, Si: 0.15-0.40%, Mn: 0.30 to 0.10 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, and the balance of Fe and other inevitable impurities.
Compared with the prior art, the invention has the beneficial effects that: in the smelting method, on one hand, the slagging-off treatment is carried out on the steel tapping process of the primary smelting in the furnace, and the slag former is strictly forbidden to be added, so that compared with the prior art that the slagging-off is not carried out and the slag former is added in the steel tapping process, the smelting method is beneficial to controlling and improving the SiO in the inclusions2The content of the components reduces the violent fluctuation and uncontrollable property of inclusion components in molten steel; on the other hand, after the target components and the temperature are adjusted in the external refining process, a refining covering agent is added, and then inclusions are removed through soft stirring or vacuum refining, so that the component content in the inclusions is further effectively controlled; on the other hand, in the inclusion removing process, large-size inclusions are further removed under the action of electromagnetic centrifugal force, so that molten steel is further purified, and finally, SiO in the inclusions, the size of which is less than or equal to 25 mu m, is obtained2The high-purity molten steel with the component content of more than or equal to 40 percent can meet the requirements of low drawing wire breakage rate, low strand twisting wire breakage rate and the like when the wire rod processed by the molten steel is applied to a deep drawing process; moreover, through improving the cleanliness of the wire rod, when the ultra-high strength steel cord with the monofilament tensile strength being more than or equal to 3100Mpa is processed, the requirement on the drawing strength of the wire rod is properly reduced to be less than 1150Mpa, so that the low-strength wire rod is applied to the preparation of the ultra-high strength steel cord.
Detailed Description
An embodiment of the present invention provides a molten steel smelting method and a wire rod for deep drawing processed from molten steel obtained by the smelting method, that is, the wire rod can be used in a deep drawing process for further processing into steel cords, high-pressure hose steel wires, cutting steel wires, and the like. Specifically, the wire rod comprises the following chemical components in percentage by mass: c: 0.18% -0.91%, Si: 0.15-0.40%, Mn: 0.30 to 0.10 percent of the total weight of the alloy, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, and the balance of Fe and other inevitable impurities.
In a preferred embodiment, the smelting method includes molten iron desulfurization, primary smelting in a furnace, refining outside the furnace, and inclusion removal, which are performed sequentially.
The recarburizer, the ferrosilicon and the manganese metal are sequentially added in the tapping process of the primary smelting process in the furnace without adding other slagging agents, more than 90% of slag on the surface of the tapping molten steel is removed after tapping is finished, slagging treatment is carried out in the tapping process, and the slagging agent is strictly forbidden to be added2The content of the components reduces the violent fluctuation and uncontrollable property of inclusion components in molten steel.
The external refining process comprises the following steps: adjusting the chemical components and the temperature of the molten steel; adding 8-12 kg/t of refining covering agent to the surface of the molten steel, and electrifying to melt the refining covering agent; removing the inclusion in the molten steel by soft stirring or vacuum refining. Therefore, the inclusion in the molten steel can be removed quickly, and the component content in the inclusion is further effectively controlled.
In the inclusion removing process, molten steel refined outside the furnace is transferred to a tundish with an electromagnetic induction function, and inclusions in the molten steel are removed under the action of electromagnetic centrifugal force, so that large-size inclusions can be further removed, and the molten steel can be further purified.
Based on the smelting method of the embodiment, the size of the obtained molten steel inclusion is less than or equal to 25 mu m, and SiO in the inclusion2The content of the components is more than or equal to 40 percent, and when the wire rod processed by the molten steel is applied to a deep drawing process, the wire rod can meet the requirements of low drawing wire breakage rate, low strand twisting wire breakage rate and the like; even further, the obtained molten steel not only meets the requirements that the size of the inclusions is less than or equal to 25 mu m and SiO in the inclusions2The content of the component is more than or equal to 40 percent, and the content of CaO component is less than or equal to 30 percent, and Al2O3The content of the components is less than or equal to 10 percent.
The following specifically describes each step in the smelting method.
(1) Molten iron desulphurization
And (3) desulfurizing the blast furnace molten iron in a KR desulfurizing device, wherein the S content of the desulfurized molten iron is less than or equal to 0.002%.
(2) Primary smelting in furnace
Firstly, dephosphorizing and decarbonizing the molten iron after the molten iron desulphurization process by adopting a converter or an electric furnace, wherein the molten iron accounts for more than or equal to 85% of the total loading amount when the converter is adopted for dephosphorizing and decarbonizing, and the molten iron accounts for more than or equal to 10% of the total loading amount when the electric furnace is adopted for dephosphorizing and decarbonizing; then, in the tapping process, the carburant, the ferrosilicon and the manganese metal are added in sequence without adding other slagging agents, more than 90% of slag on the surface of the molten steel is removed after tapping, the tapping process is also a deoxidation alloying and slagging process actually, and the slagging process is beneficial to controlling and improving SiO in the inclusions by slagging treatment and strictly adding the slagging agents2The content of the components reduces the violent fluctuation and uncontrollable property of the components of the inclusions in the molten steel, and reduces the content of CaO component and Al in the inclusions2O3The contents of the components.
And preferably, the temperature of the molten steel discharged in the primary smelting process in the furnace is controlled to 1180-1120 ℃, P is less than or equal to 0.015%, C is: 0.3 to 0.1 percent. The component content of the inclusion can be effectively controlled by controlling the high-temperature tapping.
(3) External refining
Firstly, adjusting the chemical components and the temperature of the molten steel discharged in the primary smelting process in the furnace in an LF (ladle furnace) refining furnace to quickly adjust the chemical components and the temperature of the molten steel to a target range, specifically adjusting the temperature of the molten steel to the target range through electrifying and temperature control, measuring the components of a molten steel discharged in the primary smelting process in the furnace, and then supplementing carbon powder and alloy according to the component results to adjust the chemical components of the molten steel to the target range; then, adding 8-12 kg/t of refining covering agent to the surface of the molten steel in the LF refining furnace, and quickly electrifying for 5-10 minutes to melt the refining covering agent, so as to further effectively control the component content in the inclusions; finally, removing the inclusions in the molten steel by soft stirring or vacuum refining.
According to the above, pass through the furnaceThe control of the tapping process of the refining, the control of the refining covering agent and the bottom-blown argon gas in the secondary refining, etc. can control SiO in the inclusions of the molten steel2The content of the components is more than or equal to 40 percent.
Preferably, after 8-12 kg/t of refining covering agent is added to the surface of the molten steel in the LF refining furnace, the intensity of argon blown from the bottom of a ladle of the LF refining furnace is controlled to be less than or equal to 0.005Nm3V (t.min), thereby reducing the influence of the refining covering agent on the precise regulation and control of the inclusion components, inhibiting the reaction between the slag and the molten steel and further controlling the SiO in the inclusions of the molten steel2The content of the component is more than or equal to 40 percent, the content of the CaO component is less than or equal to 30 percent, and Al2O3The content of the components is less than or equal to 10 percent.
When the inclusion in the molten steel is removed by soft stirring, the ladle bottom argon blowing strength of the LF refining furnace is controlled to be 0.001Nm3/(t·min)～0.005Nm3V (t.min); when impurities are removed through vacuum refining in an RH vacuum furnace, treating molten steel for 15-20 minutes in a high vacuum environment with the vacuum degree of a vacuum chamber of the RH vacuum furnace being less than or equal to 1.5 mbar; when the inclusions are removed through vacuum refining of the VD/VOD vacuum furnace, the molten steel is treated for 20-30 minutes in a high-vacuum environment with the vacuum degree of a vacuum chamber of the VD/VOD vacuum furnace being less than or equal to 1.5 mbar.
(4) Removal of inclusions
And transferring the molten steel of the steel refined outside the furnace to a tundish with an electromagnetic induction function, and under the action of electromagnetic centrifugal force, removing large-size inclusions in the molten steel, further removing the large-size inclusions, so that the molten steel is further purified, and finally obtaining the molten steel with the inclusion size less than or equal to 25 mu m.
Further preferably, the tundish has two electromagnetic induction channels, and in the step of removing the inclusions, the voltage of the electromagnetic induction coil is controlled to be 200-1500V, and the frequency is controlled to be 300-800 Hz.
The molten steel discharged in the fed inclusion removing process is the molten steel obtained by the smelting method, and based on the smelting method of the embodiment, the obtained molten steel meets the conditions that the size of the inclusions is less than or equal to 25 mu m and SiO in the inclusions2The content of the component is more than or equal to 40 percent, even the content of the CaO component is less than or equal to 30 percent, and Al2O3The content of the components is less than or equal to 10 percent, the high-cleanliness molten steel is high-cleanliness molten steel, and the high-cleanliness wire rod can be processed by the conventional procedures of continuous casting, cogging, high-speed rolling, temperature control cooling and the like.
The following is a description of the specific implementation of the smelting process and the quality of the molten steel obtained by the smelting process, using 8 examples numbered a-h.
(1) Molten iron desulphurization
An appropriate amount of blast furnace hot metal was desulfurized in a KR desulfurization apparatus, and basic information such as the hot metal temperature before desulfurization, the hot metal weight, the S content, and the S content after desulfurization in each example is shown in table 1.
[ Table 1]
Furnace number
Temperature of molten iron,. degree.C
Weight of molten iron, t
S, wt% before desulfurization
S, wt% after desulfurization
a
1353
88
0.041
0.0014
b
1351
11
0.032
0.0020
c
1359
12
0.035
0.0001
d
1355
11
0.031
0.0011
e
1354
114
0.043
0.0015
f
1352
115
0.031
0.0020
g
1358
112
0.045
0.0009
h
1351
111
0.039
0.0011
(2) Primary smelting in furnace
Aiming at four embodiments with serial numbers a-d, molten iron obtained after the molten iron is desulfurized in the step (1) and a clean scrap steel worker are added into an electric furnace of 100t together, and then desiliconization, dephosphorization and decarburization heating are carried out in the electric furnace; then, a carburant, ferrosilicon and manganese metal are added in sequence without adding other slag formers in the tapping process, and more than 90% of slag on the surface of the molten steel is removed after tapping. The weight of molten iron charged into the electric furnace, the molten iron ratio (i.e., molten iron weight/total charged amount), the tapping temperature, the tapping C content, the tapping P content, the slag raking rate of the molten steel surface, and the like are shown in table 2.
Aiming at four embodiments with serial numbers of e-h, molten iron obtained after the molten iron is desulfurized in the step (1) and a clean scrap steel worker are added into a 120t converter together, and then desiliconization, dephosphorization and decarburization heating are carried out in the converter; then, a carburant, ferrosilicon and manganese metal are added in sequence without adding other slag formers in the tapping process, and more than 90% of slag on the surface of the molten steel is removed after tapping. The information on the weight of molten iron charged into the converter, the molten iron ratio (i.e., molten iron weight/total charged amount), the tapping temperature, the tapping C content, the tapping P content, the slag raking rate on the molten steel surface, and the like is shown in table 2.
[ Table 2]
Furnace number
Weight of molten iron, t
Ratio of molten iron
Tapping temperature, DEG C
Tapping C%
Tapping P%
Slag rate of slag removal%
a
88
0.18
1192
0.44
0.001
90
b
11
0.10
1180
0.10
0.010
98
c
12
0.14
1120
0.30
0.008
98
d
11
0.19
1195
0.42
0.015
95
e
114
0.81
1182
0.44
0.008
90
f
115
0.81
1191
0.50
0.011
95
g
112
0.85
1191
0.30
0.009
94
h
111
0.89
1195
0.42
0.013
91
(3) External refining
Firstly, the primarily smelted steel liquid in the furnace in the step (2) is transferred to an LF refining furnace, the chemical components and the temperature of the steel liquid are adjusted in the LF refining furnace, so that the chemical components and the temperature of the steel liquid are quickly adjusted to a target range, the temperature of the steel liquid is adjusted to the target range through electrifying and temperature control, the components of a steel liquid sample initially smelted in the furnace are measured, and then carbon powder and alloy are added according to the component results, so that the chemical components of the steel liquid are adjusted to the target range.
And then, adding a refining covering agent to the surface of the molten steel in the LF refining furnace, and quickly electrifying for 5-10 minutes to melt the refining covering agent.
The information of the amount of the refining covering agent, the refining time, the ladle bottom argon blowing strength of the LF refining furnace, and the like is shown in Table 3.
[ Table 3]
Finally, aiming at the two embodiments with the serial numbers d and h, removing the impurities in the molten steel in the LF refining furnace through soft stirring, wherein the soft stirring time is shown in the table 4; in the six embodiments of serial numbers a to c and e to f, the molten steel in the LF refining furnace is transferred to a vacuum device, and impurities in the molten steel are removed by vacuum refining, wherein the specific information of the vacuum device, the vacuum degree of a vacuum chamber of the vacuum device, the high vacuum time and the like is shown in Table 4.
[ Table 4]
Furnace number
Time of soft stirring, min
Vacuum device
Vacuum degree, mbar
High vacuum time, min
a
-
RH
1.5
15
b
-
VD
0.5
20
c
-
VOD
0.9
30
d
25
-
-
-
e
-
RH
0.5
20
f
-
VD
0.51
20
g
-
VOD
1.5
30
h
25
-
-
-
(4) Removal of inclusions
And (4) transferring the molten steel refined outside the furnace in the step (3) to an electromagnetic induction tundish with two electromagnetic induction channels, and controlling the voltage and the frequency of an electromagnetic induction coil according to the table 5.
[ Table 5]
Furnace number
Voltage, V
Frequency, Hz
a
200
300
b
300
400
c
1200
800
d
100
500
e
200
300
f
300
400
g
1200
800
h
100
500
Finally, the sizes of inclusions in the molten steel obtained by the smelting method are detected, and the sizes of the inclusions in the molten steel obtained in the eight embodiments with the serial numbers of a-h are all less than or equal to 25 mu m; and the obtained molten steel was subjected to inclusion component detection to obtain main inclusion component information as shown in table 1.
[ Table 1]
Furnace number
Al2O3Content, wt%
CaO content in wt%
SiO2Content, wt%
a
9.1
25.3
54
b
8.3
18.1
51
c
10.0
30.0
40
d
1.8
21.1
51
e
9.1
25.3
51
f
8.3
30.0
40
g
10.0
21.4
55
h
1.8
23.1
58
As can be seen from Table 1, the molten steels obtained in the eight examples with the numbers a to h all satisfy the SiO content in the inclusions2The content of the component is more than or equal to 40 percent, the content of the CaO component is less than or equal to 30 percent, and Al2O3The content of the components is less than or equal to 10 percent, and compared with the prior art, the content of SiO in the inclusions can be obviously improved2The component content is reduced, CaO and Al are reduced2O3And the content of harmful components is very beneficial to improving the drawing performance of the wire rod.