CN110523937B

CN110523937B - Pressing method and device

Info

Publication number: CN110523937B
Application number: CN201910840370.9A
Authority: CN
Inventors: 赵新宇; 刘洋; 甄新刚; 赵晶; 王臻明; 王玉龙; 王俊; 吕延春; 邹扬; 秦丽晔; 张苏渊; 王海宝; 樊艳秋; 柴玉国
Original assignee: Shougang Corp
Current assignee: Shougang Corp
Priority date: 2019-09-06
Filing date: 2019-09-06
Publication date: 2021-07-23
Anticipated expiration: 2039-09-06
Also published as: CN110523937A

Abstract

The embodiment of the invention provides a pressing method, which comprises the following steps: obtaining the temperature T of the geometric central point under any fan-shaped section of the continuous casting machine_X(ii) a When casting a casting blank, according to the solidus temperature T of the casting blank_sAnd T_XDetermining the difference dt_c(ii) a Determining said dt at different depression modes_cDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached in the temperature interval to which the temperature interval belongs_XAnd the solidus temperature T_sThe first rolling reduction is 0-15 mm when the first rolling reduction is consistent; when the casting blank pulling speed is increased, according to T_XDetermining the solid fraction fs of the geometric center point_c(ii) a Determination of the solid fraction fs_cDetermining a corresponding second reduction according to the condition interval and a preset mapping table until the casting blank is finished; the mapping table is also used for representing the corresponding relation between the condition interval and the second rolling reduction, and the second rolling reduction is 0-20 mm.

Description

Pressing method and device

Technical Field

The invention belongs to the technical field of continuous casting processes, and particularly relates to a pressing method and a pressing device.

Background

The core quality problem of the continuous casting slab always troubles continuous casting workers, and particularly along with the development of pipeline steel, acid-resistant container steel and high-grade marine steel, users have higher and higher requirements on the core quality of the extra-thick slab.

In the prior art, the quality of the core of the slab is generally improved by a soft reduction technology, but the traditional soft reduction method can only improve the phenomenon of center segregation, but the problems of loose and shrinkage cavity of the core of the continuous casting slab cannot be improved, so the quality of the core of the slab cannot be further improved.

Disclosure of Invention

Aiming at the problems in the prior art, the embodiment of the invention provides a reduction method and a reduction device, which are used for solving the technical problem that the core part quality of a continuous casting blank cannot be further mentioned as the core part porosity and shrinkage cavity of the continuous casting blank cannot be improved in the prior art.

The embodiment of the invention provides a pressing method, which comprises the following steps:

obtaining the temperature T of the geometric central point under any fan-shaped section of the continuous casting machine_XThe geometric center point is the intersection point of the casting blank center line below the corresponding sector section and the projection of the center line of the pressing roller on the casting blank;

when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c；

Determining said d at different depression modes_tcThe temperature range is based on the temperature range and the preset mappingThe corresponding first reduction is determined by the dial gauge until T_XThe solidus temperature Ts is consistent; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm;

when the pulling speed of the casting blank is increased, according to the T_XDetermining the solid fraction fs of the geometric center point_c；

Determining the solid phase fraction fs_cDetermining a corresponding second reduction according to the condition interval and the mapping table until the casting blank is finished; the mapping table is further used for representing the corresponding relation between the condition interval and the second rolling reduction, and the second rolling reduction is 0-20 mm.

In the foregoing solution, when the pressing mode is a first pressing mode, the temperature interval is a first temperature interval, the mapping table is a first mapping table, and the first pressing amount determined according to the temperature interval and a preset mapping table includes:

when determining dt_c>At 0, dt_cCorresponding temperature interval of 0<dt_c<And searching a corresponding first reduction in the first mapping table according to the first temperature interval, wherein the first reduction is 0 mm.

In the foregoing solution, when the pressing mode is a first pressing mode, the condition interval is a first condition interval, the mapping table is a first mapping table, and determining a corresponding second pressing amount according to the condition interval and a preset mapping table includes:

when the determination is 0.95<fs_cWhen the rolling reduction is less than or equal to 1, searching a corresponding second rolling reduction in the first mapping table according to the first conditional interval, wherein the second rolling reduction is 0 mm;

when determining 0.8<fs_cWhen the rolling reduction is less than or equal to 0.95, searching a corresponding second rolling reduction in the mapping table according to the first conditional interval, wherein the second rolling reduction is 20 mm;

when determining 0<fs_cWhen the mapping table is less than or equal to 0.8, searching the first mapping table according to the first conditional intervalAnd the corresponding second reduction amount is 0 mm.

In the above scheme, the signal is according to the T_XDetermining the solid fraction fs of the geometric center point_cThe method comprises the following steps:

according to the formula

Determining the solid fraction f of the geometric center point_sc(ii) a Wherein, T is_LIs the liquidus temperature of the cast slab, T_sIs the solidus temperature of the casting blank, T_XThe temperature of the geometric center point below any fan-shaped section of the continuous casting machine.

In the foregoing solution, when the pressing mode is a second pressing mode, the temperature interval is a second temperature interval, the mapping table is a second mapping table, and the determining a first pressing amount according to the temperature interval and a preset mapping table includes:

when determining dt_c>At 50, the d_tcThe corresponding second temperature interval is 50<dt_c<Searching a corresponding first reduction in the second mapping table according to the second temperature interval, wherein the first reduction is 0 mm;

when 20 is turned on<dt_cWhen the temperature is less than or equal to 50 ℃, searching a corresponding first reduction in the second mapping table according to the second temperature interval, wherein the first reduction is 10 mm;

when determining 0<dt_cAnd when the temperature is less than or equal to 20 ℃, searching a corresponding first reduction amount in the second mapping table according to the second temperature interval, wherein the first reduction amount is 15 mm.

In the foregoing solution, when the pressing mode is a second pressing mode, the condition interval is a second condition interval, the mapping table is a second mapping table, and the second pressing amount determined according to the condition interval and a preset mapping table includes:

when the determination is 0.95<fs_cWhen the rolling reduction is less than or equal to 1, searching a corresponding second rolling reduction in the second mapping table according to the second conditional interval, wherein the second rolling reduction is 15 mm;

when determining 0.8<fs_cWhen the rolling reduction is less than or equal to 0.95, searching a corresponding second rolling reduction in the second mapping table according to the second condition interval, wherein the second rolling reduction is 20 mm;

when determining 0.5<fs_cWhen the rolling reduction is less than or equal to 0.8, searching a corresponding second rolling reduction in the second mapping table according to the second condition interval, wherein the second rolling reduction is 10 mm;

when determining 0<fs_cAnd when the rolling reduction is less than or equal to 0.5, searching a corresponding second rolling reduction in the second mapping table according to the second condition interval, wherein the second rolling reduction is 0 mm.

The present invention also provides a screw down device, the device comprising:

an acquisition unit for acquiring the temperature T of the geometric central point below any sector section of the continuous casting machine_XThe geometric center point is the intersection point of the casting blank center line below the corresponding sector section and the projection of the center line of the pressing roller on the casting blank;

a first determination unit for determining a solidus temperature T of the cast slab when the cast slab is started_sAnd said T_XDetermining the difference dt_c；

A second determination unit for determining d in different pressing modes_tcDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XThe solidus temperature Ts is consistent; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm;

Determining the solid phase fraction fs_cDetermining a corresponding second reduction according to the condition interval and the mapping table until the casting blank is finished; the mapping table is further used for representing the corresponding relation between the condition interval and the second rolling reduction.

In the foregoing solution, the first determining unit is specifically configured to:

under the condition that the pressing mode is a first pressing mode, the temperature interval is a first temperature interval, the mapping table is a first mapping table, and when dt is determined_c>At 0, dt_cCorresponding temperature interval of 0<dt_c<And searching a corresponding first reduction in the first mapping table according to the first temperature interval, wherein the first reduction is 0 mm.

under the condition that the pressing mode is a first pressing mode, the condition interval is a first condition interval, the mapping table is a first mapping table, and when the condition interval is determined to be 0.95<fs_cWhen the rolling reduction is less than or equal to 1, searching a corresponding second rolling reduction in the first mapping table according to the first conditional interval, wherein the second rolling reduction is 0 mm;

when determining 0<fs_cAnd when the rolling reduction is less than or equal to 0.8, searching a corresponding second rolling reduction in the first mapping table according to the first conditional interval, wherein the second rolling reduction is 0 mm.

In the foregoing solution, the second determining unit is specifically configured to:

when the pulling speed of the casting blank is increased, according to a formula

Determining the solid fraction fs of the geometric center point_c(ii) a Wherein, T is_LIs the liquidus temperature of the cast slab, T_sIs the solidus temperature of the casting blank, T_XThe temperature of the geometric center point below any fan-shaped section of the continuous casting machine.

The embodiment of the invention provides a screw-down method and a screw-down device, wherein the method comprises the step of obtaining the temperature T of a geometric central point below any fan-shaped section of a continuous casting machine_XThe geometric central point is the central line of the casting blank below the corresponding sector sectionThe intersection point with the central line of the lower pressing roller; when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c(ii) a Determining said dt at different depression modes_cDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XThe solidus temperature Ts is consistent; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm; when the pulling speed of the casting blank is increased, according to the T_XDetermining the solid fraction fs of the geometric center point_c(ii) a Determining the solid phase fraction fs_cDetermining a corresponding second reduction according to the condition interval and a preset mapping table until the casting blank is finished; the mapping table is also used for representing the corresponding relation between the condition interval and the second rolling reduction, and the second rolling reduction is 0-20 mm; therefore, at the solidification front of the casting blank, because the surface temperature is lower than the core temperature, and the first reduction is 0-15 mmm and the second reduction is 0-20 mm, which is equivalent to the large reduction of the core, most of the reduction can be transferred to the core of the casting blank, so that the core looseness can be reduced, the holes in the core of the casting blank can be eliminated to the greatest extent in the contraction process, and the core quality is improved; in the continuous casting process, the reduction is dynamically adjusted according to the temperature of the geometric central point below any fan-shaped section of the continuous casting machine, so that a wedge-shaped blank caused in the large reduction process can be avoided, and the reduction effect is further ensured.

Drawings

FIG. 1 is a schematic flow chart of a pressing method according to an embodiment of the present invention;

FIG. 2 is a schematic view of a geometric center point below any one of the segments of the continuous casting machine according to one embodiment of the present invention;

fig. 3 is a schematic structural diagram of a pressing method apparatus according to a second embodiment of the present invention.

Detailed Description

Aiming at solving the problem that the core of the continuous casting blank can not be improved in the prior artThe problems of looseness and shrinkage cavity cause the core quality of the continuous casting blank not to be further mentioned. The invention provides a pressing method and a device, comprising the following steps: obtaining the temperature T of the geometric central point under any fan-shaped section of the continuous casting machine_XThe geometric center point is the intersection point of the central line of the casting blank below the corresponding sector section and the central line of the pressing roller; when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c(ii) a Determining said dt at different depression modes_cDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XThe solidus temperature Ts is consistent; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm; when the pulling speed of the casting blank is increased, according to the T_XDetermining the solid fraction fs of the geometric center point_c(ii) a Determining the solid phase ratio f_scDetermining a corresponding second reduction according to the condition interval and a preset mapping table until the casting blank is finished; the mapping table is further used for representing the corresponding relation between the condition interval and the second rolling reduction, and the second rolling reduction is 0-20 mm.

The technical solution of the present invention is further described in detail by the accompanying drawings and the specific embodiments.

Example one

The embodiment provides a pressing method, which comprises the following steps:

s110, acquiring the temperature T of the geometric central point below any fan-shaped section of the continuous casting machine_XThe geometric center point is the intersection point of the central line of the casting blank below the corresponding sector section and the central line of the pressing roller;

firstly, the temperature T of the geometric central point below any fan-shaped section of the continuous casting machine is obtained_XAnd the geometric central point is the intersection point of the casting blank central line below the corresponding sector section and the projection of the central line of the pressing roller on the casting blank.

Referring to fig. 2, fig. 2 shows a casting blank schematic diagram, wherein 1 is a casting blank, the casting blank is performed by using a press roll 3 and an auxiliary roll 4, and 5 in fig. 2 is a geometric central point below any sector of a continuous casting machine.

S111, when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c；

When the casting blank is started, the press roll is in the standby position, when the head of the casting blank passes below the press roll, the mark 5 in figure 2 begins to appear, and T is just started to cast at the moment_XThe temperature is low, and the temperature is required to be according to the solidus temperature T of the casting blank_sAnd said T_XA difference is determined. Then by the difference dt_cThe amount of the press roller is determined as a determination condition.

S112, under different pressing modes, determining dt_cDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XAnd the solidus temperature T_sThe consistency is achieved;

here, the set mapping tables are different in different depression modes. In the first pressing mode, the corresponding mapping table is a first mapping table, and a first temperature interval and a first condition interval are set in the first mapping table. Therefore, when the depression mode is the first depression mode, dt is determined first_cDetermining a corresponding first reduction amount according to the first temperature interval and a preset first mapping table until T is within the first temperature interval_XAnd the solidus temperature T_sThe consistency is achieved; the first rolling reduction is 0-15 mm.

Wherein the first depression mode may include: the first temperature interval is divided into (0, ∞) and dt is the determination object of the first temperature interval_cDividing the first conditional interval into (0, 0.8)]、(0.8，0.95]、(0.95，1]The first conditional section is fs_c。

Specifically, in the first depression mode, the first mapping table may be as shown in table 1:

TABLE 1

case	Determination target	start	end	Reduction amount [ mm ]]
					case1	fs_c	0	0.8	0
case2	fs_c	0.8	0.95	20
					case3	fs_c	0.95	1	0
case4	dt_c	0	∞	0

It can be seen that the first mapping table is used for representing the corresponding relationship between the first temperature interval and the first reduction, and is also used for representing the relationship between the first condition interval and the second reduction. Then in the first reduction mode, when the cast slab is cast, T is the time_XIs below the solidus temperature T_sOf (d) d_cIs greater than 0. The first reduction determined according to the temperature interval and a preset mapping table comprises:

when determining dt_c>At 0, dt_cThe corresponding first temperature interval is 0<dt_c<And at the moment, case4 is met, and a corresponding first reduction is searched in the first mapping table according to a first temperature interval, wherein the first reduction is 0 mm. That is, the press roll 3 is at the reference nip position at this time.

S113, when the pulling speed of the casting blank is increased, according to the T_XDetermining the solid fraction fs of the geometric center point_c(ii) a Determining the solid phase fraction fs_cDetermining a corresponding second reduction according to the condition interval and a preset mapping table until the casting blank is finished;

with increasing pull rate, T_XGradually increasing, and determining the solid fraction f of the geometric center point according to the formula (1)_sc：

In the formula (1), the T_LIs the liquidus temperature of the cast slab, T_sIs the solidus temperature of the casting blank, T_XThe temperature of the geometric center point below any fan-shaped section of the continuous casting machine.

When fs is_cAfter the determination, the solid phase ratio fs is determined_cAnd determining a corresponding second reduction according to the first condition interval and a preset first mapping table until the casting blank is finished.

As shown in Table 1, the first mapping table is also used for representing the corresponding relationship between the first condition interval and the second rolling reduction, and the second rolling reduction can be 0-20 mm.

Determining a corresponding second reduction amount according to the condition interval and a preset mapping table, wherein the step of determining the corresponding second reduction amount comprises the following steps:

when determining 0.8<fs_cWhen the rolling reduction is less than or equal to 0.95, searching a corresponding second rolling reduction in the first mapping table according to the first conditional interval, wherein the second rolling reduction is 20 mm;

For example, as the pull rate increases, when T_XEqual to solidus temperature T_sAt this time fs_C1, satisfying case3, wherein the second rolling reduction of the lower roller is 0 mm;

then increasing with the pulling speed as fs_cWhen 0.95 is satisfied, case2 is satisfied, and the second rolling reduction of the lower roll is 20mm, and the lower roll is pressed down 20mm from the reference roll gap.

Final pull rate stabilization, fs_cWhen the rolling reduction is equal to 0.87, case2 is met, and the second rolling reduction is continuously kept to be 20 mm;

after the casting is finished, the pulling speed is reduced, T_XReduction of fs_cIf case2 is satisfied, the second reduction amount of the press roller is 0mm, and the press roller is continuously maintained at the reference nip position.

Thus according to T_XAnd continuously adjusting the reduction amount of the press roll until the tail of the casting blank leaves the lower part of the press roll.

As an alternative embodiment, when the depression mode is the second depression mode, the corresponding mapping table is the second mapping table, and the second mapping table is different from the first mapping table. Similarly, the second mapping table has a second temperature interval and a second condition interval, and the second mapping table is used for representing the relationship between the second temperature interval and the first rolling reduction and also for representing the corresponding relationship between the second condition interval and the second rolling reduction.

It should be noted that the second temperature interval in the second mapping table is different from the first temperature interval in the first mapping table, and the second condition interval in the second mapping table is also different from the first condition interval in the first mapping table.

The second mapping table may be as shown in table 2, and accordingly, the second depression mode may include: dividing the second temperature interval into (50, ∞), (20, 50)]、(0，20](ii) a The second temperature interval is determined to be dt_cDividing the second conditional interval into (0, 0.5)]、(0.5，0.8]、(0.8，0.95]、(0.95，1]The second conditional section is fs_c。

TABLE 2

case	Determination target	start	end	Reduction amount [ mm ]]
					case1′	fs_c	0	0.5	0
case2′	fs_c	0.5	0.8	10
					case3′	fs_c	0.8	0.95	20
case4′	fs_c	0.95	1	15
					case5′	dt_c	0	20℃	15
case6′	dt_c	20℃	50℃	10
					case7′	dt_c	50℃	∞	0

Under the second pressing mode, the first pressing amount determined according to the temperature interval and the preset mapping table comprises the following steps:

when determining dt_c>At 50, the dt_cThe corresponding second temperature interval is 50<dt_c<Searching a corresponding first reduction in the second mapping table according to a second temperature interval, wherein the first reduction is 0 mm;

when 20 is turned on<dt_cWhen the temperature is less than or equal to 50 ℃, searching a corresponding first reduction in a second mapping table according to a second temperature interval, wherein the first reduction is 10 mm;

when determining 0<dt_cAnd when the temperature is less than or equal to 20 ℃, searching a corresponding first reduction in the second mapping table according to the second temperature interval, wherein the first reduction is 15 mm.

As an optional embodiment, in the second depression mode, the second depression amount determined according to the condition interval and the preset mapping table includes:

when the determination is 0.95<fs_cWhen the rolling reduction is less than or equal to 1, searching a corresponding second rolling reduction in a second mapping table according to a second conditional interval, wherein the second rolling reduction is 15 mm;

when determining 0.8<fs_cWhen the rolling reduction is less than or equal to 0.95, searching a corresponding second rolling reduction in a second mapping table according to a second conditional interval, wherein the second rolling reduction is 20 mm;

when determining 0.5<fs_cWhen the rolling reduction is less than or equal to 0.8, searching a corresponding second rolling reduction in a second mapping table according to a second conditional interval, wherein the second rolling reduction is 10 mm;

when 0 is determined.<fs_cAnd when the rolling reduction is less than or equal to 0.5, searching a corresponding second rolling reduction in a second mapping table according to a second condition interval, wherein the second rolling reduction is 0 mm.

For example, after casting, T_XIs below the solidus temperature T_s50℃，dt_c>50, case 7' is satisfied, and the corresponding first rolling reduction is searched in the second mapping table according to the second temperature interval, wherein the first rolling reduction is 0mm, that is, the press roll 3 is at the reference roll gap position at this time.

T increases with the pull rate_XWill rise until dt_cWhen the temperature is less than or equal to 50 ', case 6' is satisfied, and corresponding first pressing amount, first pressure, is searched in the second mapping table according to the second temperature intervalThe lower amount is 10 mm. That is, the press roll 3 is pressed down 10mm at the reference nip position.

When dt is_cAnd when the temperature is less than or equal to 20, case 5' is met, and a corresponding first pressing amount is searched in the second mapping table according to the second temperature interval, wherein the first pressing amount is 15mm, that is, the pressing roller 3 is pressed downwards at the reference roller gap position by 15mm at the time.

When T is_XEqual to solidus temperature T_sAt this time fs_cWhen case 4' is satisfied, the corresponding second rolling reduction is found in the second mapping table according to the second condition interval, where the second rolling reduction is 15mm, that is, the bottom roller is pressed down 15mm at the reference roll gap position.

Then increasing with the pulling speed as fs_cWhen the rolling force is equal to 0.87, case 3' is satisfied, and a corresponding second rolling reduction of 20mm is searched in the second mapping table according to the second condition interval, that is, the rolling roller is pressed down by 20mm at the reference roll gap position.

Thus, the reduction amount of the press roller is continuously adjusted in the pouring process according to the method until the tail of the casting blank leaves the lower part of the press roller.

Example two

Corresponding to the first embodiment, this embodiment further provides a pressing device, as shown in fig. 3, the device includes: an acquisition unit 31, a first determination unit 32, and a second determination unit 33;

the acquiring unit 31 is used for acquiring the temperature T of the geometric central point below any fan-shaped section of the continuous casting machine_XAnd the geometric central point is the intersection point of the casting blank central line below the corresponding sector section and the projection of the central line of the pressing roller on the casting blank.

When the casting blank is started, the press roll is in the standby position, when the head of the casting blank passes below the press roll, the mark 5 in figure 2 begins to appear, and T is just started to cast at the moment_XThe temperature is low, and the first determining unit 32 needs to determine the solid phase of the casting blankLinear temperature T_sAnd said T_XDetermining the difference dt_c. Then by the difference dt_cThe amount of the press roller is determined as a determination condition.

Here, the set mapping tables are different in different depression modes. In the first pressing mode, the corresponding mapping table is a first mapping table, and a first temperature interval and a first condition interval are set in the first mapping table. Therefore, when the depression mode is the first depression mode, dt is determined first_cAnd determining a corresponding first reduction amount according to the first temperature interval and a preset first mapping table, wherein the first reduction amount is 0-15 mm.

TABLE 1

It can be seen that the first mapping table is used for representing the corresponding relationship between the first temperature interval and the first reduction, and is also used for representing the relationship between the first condition interval and the second reduction. Then in the first reduction mode, when the cast slab is cast, T is the time_XIs below the solidus temperature T_sOf (d) d_cIs greater than 0. The first determination unit 32 is then arranged to:

With increasing pull rate, T_XGradually rise to the rootDetermining the solid fraction fs of the geometric center point according to the formula (1)_c：

When fs is_cAfter the determination, the second determination unit 33 is configured to: determining the solid phase fraction fs_cAnd determining a corresponding second reduction amount according to the first conditional interval and a preset first mapping table. As shown in Table 1, the first mapping table is also used for representing the corresponding relationship between the first condition interval and the second rolling reduction, and the second rolling reduction can be 0-20 mm.

The second determination unit 33 is specifically configured to:

Final pull rate stabilization, fs_cWhen 0.87 is satisfied, case2 is satisfied, and the second rolling reduction is continuously maintained at 20mm；

TABLE 2

In the second depression mode, the first determination unit 22 is configured to:

when determining dt_c>At 50, the d_tcThe corresponding second temperature interval is 50<dt_c<Searching a corresponding first reduction in the second mapping table according to a second temperature interval, wherein the first reduction is 0 mm;

As an alternative embodiment, in the second depression mode, the second determination unit 33 is configured to:

when 0 is determined.<fs_cWhen the temperature is less than or equal to 0.5, according to the second condition zoneAnd searching a corresponding second rolling reduction in a second mapping table, wherein the second rolling reduction is 0 mm.

For example, after casting, T_XIs below the solidus temperature T_s 50℃，dt_c>50, case 7' is satisfied, and the corresponding first rolling reduction is searched in the second mapping table according to the second temperature interval, wherein the first rolling reduction is 0mm, that is, the press roll 3 is at the reference roll gap position at this time.

T increases with the pull rate_XWill rise until dt_CAnd when the temperature is less than or equal to 50, case 6' is met, and the corresponding first reduction is searched in the second mapping table according to the second temperature interval, wherein the first reduction is 10 mm. That is, the press roll 3 is pressed down 10mm at the reference nip position.

The pressing method and the device provided by the embodiment of the invention have the following beneficial effects that:

the embodiment of the invention provides a pressing method and a device, wherein the method comprises the following steps: obtaining the temperature T of the geometric central point under any fan-shaped section of the continuous casting machine_XThe geometric central point is the central line of the casting blank below the corresponding sector section andthe intersection point of the central lines of the press rolls; when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c(ii) a Determining said dt at different depression modes_cDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XAnd the solidus temperature T_sThe consistency is achieved; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm; when the pulling speed of the casting blank is increased, according to the T_XDetermining the solid fraction fs of the geometric center point_c(ii) a Determining the solid phase fraction fs_cDetermining a corresponding second reduction according to the condition interval and a preset mapping table until the casting blank is finished; the mapping table is also used for representing the corresponding relation between the condition interval and the second rolling reduction, and the second rolling reduction is 0-20 mm; therefore, at the solidification front of the casting blank, because the surface temperature is lower than the core temperature, and the first reduction is 0-15 mmm and the second reduction is 0-20 mm, which is equivalent to the large reduction of the core, most of the reduction can be transferred to the core of the casting blank, so that the core looseness can be reduced, the holes in the core of the casting blank can be eliminated to the greatest extent in the contraction process, and the core quality is improved; in the continuous casting process, the reduction amount is dynamically adjusted according to the temperature of the geometric central point below any fan-shaped section of the continuous casting machine, so that a wedge-shaped blank caused in the large reduction process can be avoided, and the reduction effect and the overall quality of the casting blank are further ensured.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, and any modifications, equivalents, improvements, etc. that are within the spirit and principle of the present invention should be included in the present invention.

Claims

1. A method of screw down, the method comprising:

obtaining the lower part of any fan-shaped section of a continuous casting machineTemperature T of geometric center point_XThe geometric center point is the intersection point of the casting blank center line below the corresponding sector section and the projection of the center line of the pressing roller on the casting blank;

when the casting blank is cast, according to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c(ii) a Said dt_c＝T_s-T_X；

Determining said d at different depression modes_tcDetermining a corresponding first reduction amount according to the temperature interval and a preset mapping table until T is reached_XThe solidus temperature Ts is consistent; the mapping table is used for representing the corresponding relation between the temperature interval and the first reduction, and the first reduction is 0-15 mm;

2. The method of claim 1, wherein in a case that the depression mode is a first depression mode, the temperature interval is a first temperature interval, the mapping table is a first mapping table, and the determining a first depression amount according to the temperature interval and a preset mapping table includes:

3. The method of claim 1, wherein when the depression mode is a first depression mode, the condition interval is a first condition interval, the mapping table is a first mapping table, and the determining a corresponding second depression amount according to the condition interval and a preset mapping table comprises:

4. The method of claim 1, wherein said is based on said T_XDetermining the solid fraction fs of the geometric center point_cThe method comprises the following steps:

according to the formula

5. The method of claim 1, wherein when the pressing mode is a second pressing mode, the temperature interval is a second temperature interval, the mapping table is a second mapping table, and the determining the first pressing amount according to the temperature interval and a preset mapping table includes:

when determining dt_c>At 50, the d_tcThe corresponding second temperature interval is 50<dt_c<Infinity, searching a corresponding first reduction in the second mapping table according to the second temperature interval, wherein the first reduction isThe amount is 0 mm;

6. The method of claim 1, wherein when the depression mode is a second depression mode, the condition interval is a second condition interval, the mapping table is a second mapping table, and the second depression amount determined according to the condition interval and a preset mapping table includes:

7. A screw down device, comprising:

an acquisition unit for acquiring the temperature T of the geometric central point below any sector section of the continuous casting machine_XThe geometric center point is the intersection point of the projection of the center line of the casting blank below the corresponding sector section and the center line of the pressing roller on the casting blank in the pouring process;

a first determination unit for determining a root of the cast slab when the cast slab is castAccording to the solidus temperature T of the casting blank_sAnd said T_XDetermining the difference dt_c(ii) a Said dt_c＝T_s-T_X；

8. The apparatus of claim 7, wherein the first determining unit is specifically configured to:

9. The apparatus of claim 7, wherein the first determining unit is specifically configured to:

under the condition that the pressing mode is a first pressing mode, the condition interval is a first condition interval, the mapping table is a first mapping table, and when the condition interval is determined to be 0.95<fs_cWhen the rolling reduction is less than or equal to 1, searching a corresponding second rolling reduction in the first mapping table according to the first conditional intervalThe second rolling reduction is 0 mm;

10. The apparatus of claim 7, wherein the second determining unit is specifically configured to: