JP5383462B2 - Displacement measurement method for water-cooled copper plate - Google Patents

Description

The present invention relates to a method for measuring the displacement of a water-cooled copper plate of a continuous casting mold used for producing a slab.

Conventionally, a continuous casting mold having a water-cooled copper plate formed with a space portion penetrating in the vertical direction (hereinafter also simply referred to as a mold) is used to manufacture a slab while supplying molten steel to the space portion and cooling it. Yes.
In this mold, for example, as disclosed in Patent Document 1, a single taper (also referred to as a single taper) mold formed with one taper (inclined surface) over the casting direction of the cooling copper plate, There is a two-step taper mold formed by two tapers having different inclination angles.
However, since solidification shrinkage occurs during the solidification process of the molten steel, there is a gap between the water-cooled copper plate surface (mold inner surface) and the solidified shell formed on the molten steel mold contact surface in the direction of drawing the slab. As a result, the cooling efficiency of the corner portion of the slab was lowered as compared with other portions, and solidification delay occurred.
Therefore, as in Patent Document 2, a mold in which the shape of the surface of the water-cooled copper plate is made to correspond to the solidification profile of the slab, that is, a multi-taper mold has been proposed.

JP 2001-79650 A JP 2008-49385 A

However, the shape of the water-cooled copper plate of the mold of Patent Document 2 is a shape that considers only the solidification profile of the slab, and is not a shape that takes into account the thermal deformation that occurs in the water-cooled copper plate itself.
As shown in FIGS. 11 (A) and 11 (B), thermal deformation due to heat from the molten steel during continuous casting includes a long side (also referred to as a long piece) 91 made of a water-cooled copper plate and a back plate 92 attached to the back side. However, as shown in FIGS. 11C and 11D, a short side (also referred to as a short piece) 93 made of a water-cooled copper plate and a back plate 94 attached to the back side are integrally thermally deformed.
At this time, the long side 91 or the short side 93 is deformed larger than the back plates 92 and 94. In addition, as shown in FIGS. 11A and 11B, the mold having these water-cooled copper plates has a pair of long sides 91 on both sides in the width direction of a pair of short sides 93 arranged to face each other. The shape is sandwiched between.

Further, as shown in FIGS. 11A to 11D, this thermal deformation is a deformation in which the long side 91 and the short side 93 are inflated, and the amount of protrusion to the molten steel contact surface side is about 1 to 2 mm. May be larger than the dimension considering the solidification profile of the slab. For this reason, if such thermal deformation occurs, the performance of the mold having a multi-taper cannot be sufficiently obtained.
Furthermore, the taper shape collapses due to the deformation that causes the middle side to bulge in the long side 91 and the short side 93. As a result, the cooling of the corner portion of the slab becomes worse, and the thickness of the formed solidified shell becomes thin. Eventually, it may cause a breakout.

The present invention has been made in view of such circumstances, and it is possible to obtain a water-cooled copper plate displacement measuring method capable of sufficiently obtaining the performance of a water-cooled copper plate in consideration of the solidification profile of the slab and capable of producing a good quality slab. The purpose is to provide.

The displacement measuring method of a water-cooled copper plate according to the present invention that meets the above-mentioned object is a displacement measuring method of a water-cooled copper plate that is fixedly arranged inside a continuous casting mold,
A first distance meter is disposed on the back portion of the back plate disposed on the back side of the water-cooled copper plate, and the movement distance a of the back plate is measured by the first distance meter, and a second distance meter is disposed in the back plate. The distance b between the back plate and the water-cooled copper plate is measured by the second distance meter, and the displacement of the water-cooled copper plate is obtained from the sum of the moving distance a and the distance b.
The back portion of the back plate includes not only the back side portion of the back plate itself but also the back side rear position of the back plate.

Displacement measuring method for a water-cooled copper plate according to the present invention more rangefinder embedded in placed on the back of the back plate rangefinder and the back plate, it is possible to obtain a displacement of the water-cooled copper plate during continuous casting.
As a result, deformation of the water-cooled copper plate that affects the quality of the slab to be manufactured can be detected. Based on this data, for example, the casting conditions are changed during continuous casting, and the water-cooled copper plate accompanying thermal deformation before continuous casting. By performing the shape processing, it is possible to sufficiently obtain the performance of the water-cooled copper plate in consideration of the solidification profile of the slab and to manufacture a slab of good quality.

Further, the distance a between the back plate and the water-cooled copper plate is measured with a second distance meter embedded in the back plate by measuring the moving distance a of the back plate with a first distance meter disposed on the back of the back plate. the measured, since obtaining the displacement of the water-cooled copper plate for continuous casting from the sum of the travel distance a and the distance b, it is possible to obtain a displacement of the water-cooled copper plate with high accuracy.

(A), (B) is explanatory drawing of the displacement measuring method of the water-cooled copper plate which concerns on the 1st, 2nd embodiment of this invention, respectively. It is explanatory drawing of the displacement measuring method of the water-cooled copper plate which concerns on the 3rd Embodiment of this invention. (A) is a back view of the long side back plate showing the displacement measurement position, and (B) is a back view of the short side back plate showing the displacement measurement position. It is explanatory drawing which shows transition of the casting speed of slab. It is explanatory drawing which shows transition of the curvature deformation of the F side backplate in each displacement measurement position. It is explanatory drawing which shows transition of the curvature deformation of the N side backplate in each displacement measurement position. It is explanatory drawing which shows the curvature deformation of the casting direction of F side backplate. It is explanatory drawing which shows the curvature deformation of the casting direction of an N side backplate. (A), (B) is explanatory drawing which shows the thermal deformation distribution and curvature deformation distribution of the F side, respectively. (A), (B) is explanatory drawing which shows the thermal deformation distribution and warpage deformation distribution of the N side, respectively. (A) is a partial perspective view from the front side of the long side thermally deformed, (B) is a partial perspective view from the back side of the long side, (C) is a perspective view from the back side of the short side thermally deformed. , (D) is a perspective view from the front side of the short side.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
First, a continuous casting mold (hereinafter also simply referred to as a mold) to which the water-cooled copper plate displacement measurement method according to the first to third embodiments of the present invention is applied will be described, and then the water-cooled copper plate displacement measurement method will be described. To do.
As shown in FIGS. 1 (A) and 1 (B), the mold has a water-cooled copper plate which is fixedly arranged inside and forms a space portion 10 penetrating in the vertical direction, and molten steel 12 is supplied to the space portion 10. The slab is manufactured while cooling.

The water-cooled copper plate is composed of a pair of short sides (also referred to as short pieces) 13 opposed to each other with an interval, and a pair of long sides 14 (long pieces) arranged opposite to each other with the short sides 13 sandwiched from both sides in the width direction. (Refer to FIGS. 11A and 11B).
Back plates (support members) 15 and 16 are fixed to the back side of the short side 13 and the long side 14 made of this water-cooled copper plate by a plurality of bolts (fastening means), respectively, and the back side of the short side 13 and the long side 14 By flowing the cooling water through a number of water guide grooves provided in the vertical direction, the short side 13 and the long side 14 can be cooled and the molten steel 12 can be cooled to produce a slab.

For example, the short side 13 has a width of about 50 mm or more and 300 mm or less (equal to the interval between the pair of long sides 14) and a vertical length of about 600 mm or more and 1200 mm or less. Further, the long side 14 has a width that can change the distance between the pair of opposing short sides 13 in the range of 600 mm or more and 3000 mm or less, and the length in the vertical direction is about the same as the short side. It is. The short side 13 and the long side 14 are made of copper or a copper alloy.
Thereby, for example, a slab having a width of about 600 mm to about 3000 mm and a thickness of about 50 mm to about 300 mm can be manufactured.

Then, the displacement measuring method of the water-cooled copper plate which concerns on the 1st-3rd embodiment of this invention is demonstrated.
As shown in FIG. 1 (A), the displacement measuring method for the water-cooled copper plate according to the first embodiment of the present invention has a plurality of (here, the back plate 16) disposed on the back side of the long side 14. This is a method in which three laser displacement meters (an example of a distance meter) 19 to 21 are arranged, and the movement distance a of the back plate 16 is measured by the laser displacement meters 19 to 21. This method is effective when the back plate 16 has low rigidity and the back plate 16 expands and contracts integrally with the long side 14.

Each of the laser displacement meters 19 to 21 is arranged on the front side of the mold frame 18 that supports the mold (the side facing the back surface of the back plate 16 with a gap) with a gap in the casting direction. ing. The laser displacement meters 19 to 21 are attached only to the mold frame 18, but may be attached only to the back plate 16 (rear surface) or both the mold frame 18 and the back plate 16.
Here, the laser-type displacement meters 19, 21, and 20 have an upper portion in the height direction of the long side 14 (range from the upper end of the long side to 150 mm in the casting direction) and a lower portion (from the lower end of the long side to 200 mm upward). Range) and the central part (the part excluding the upper part and the lower part) can be measured, but the present invention is not limited to this. You may arrange.

Further, instead of the laser displacement meter, an eddy current displacement meter or a contact displacement meter may be used.
Thereby, the relative distance L1 between the back plate 16 and the mold frame 18 can be measured for each position where the laser displacement meters 19 to 21 are installed. Note that the mold frame 18 is arranged at a distance from the back plate 16 and is not thermally deformed (small thermal deformation). Therefore, by measuring the relative distance L1 before and after the start of continuous casting, the back plate 16 The movement distance a of the long side 14 can be measured, and the displacement of the long side 14 during warp deformation can be detected.

As shown in FIG. 1 (B), a method for measuring the displacement of a water-cooled copper plate according to the second embodiment of the present invention includes a plurality of (here, the back plate 15) disposed on the back side of the short side 13. In this method, three eddy current displacement meters (an example of a distance meter) 24 to 26 are arranged, and the movement distance a ′ of the back plate 15 is measured by the eddy current displacement meters 24 to 26.
Each of the eddy current displacement meters 24 to 26 has an interval across the casting direction on the front side of the reference bar 27 arranged on the back side of the back plate 15 (the side facing the back side of the back plate 15). Are arranged. The reference bar 27 is attached to the upper and lower portions of the back plate 15 via support portions 28 and 29.

With this configuration, the relative distance L2 between the back plate 15 and the reference bar 27 can be determined by the eddy current displacement meters 24 to 26 for each position where the eddy current displacement meters 24 to 26 are installed. It can be measured. Therefore, the amount of warpage deformation of the short side 13 with respect to the reference bar 27 is obtained from the relative distance L2 between the back plate 15 and the reference bar 27.
Since the reference bar 27 is not thermally deformed (thermal deformation is small), the movement distance a ′ of the back plate 15 can be measured by measuring the relative distance L2 before and after the start of continuous casting, and the warp of the short side 13 can be measured. Displacement during deformation can be detected.

As shown in FIG. 2, the displacement measuring method of the water-cooled copper plate according to the third embodiment of the present invention includes a plurality of (here, the back plate 40 disposed on the back side of the short side 39 made of the water-cooled copper plate). 3) eddy current displacement meters (an example of a distance meter) 41 to 43 are embedded, and the distance b between the back plate 40 and the short side 13 is measured by the eddy current displacement meters 41 to 43. . This method is effective when the back plate 40 has high rigidity and is thermally deformed mainly by the short side 39. This method can also be applied to the long side.
The short side 39 has the same configuration as the short side 13, and the back plate 40 has the same configuration as the back plate 15 except that the eddy current displacement meters 41 to 43 are provided. It is. In addition, numbers 44 and 45 in FIG. 2 are water guide grooves through which cooling water flows, and number 46 is an O-ring that prevents leakage of cooling water from between the short side 39 and the back plate 40.

The eddy current displacement meter 41 (the same applies to each of the eddy current displacement meters 42 and 43) has a detection portion 48 to which a cord 47 is connected, and this detection portion 48 is in a through hole 49 formed in the back plate 40. It is embedded in. The through holes 49 are formed with a gap in the width direction of the back plate 40, but may be formed with a gap in the casting direction.
The detection unit 48 is positioned by the sensor head pressing unit 50 so that the front end surface of the detection unit 48 contacts the back surface of the short side 39 (there may be a gap). O-rings 51 and 52 are attached between the detection unit 48 and the sensor head pressing unit 50 and between the sensor head pressing unit 50 and the inner surface of the through hole 49, respectively, to prevent leakage of cooling water. ing.

The sensor head presser 50 is positioned by a fixing bolt 54 in which a through hole 53 for inserting the cord 47 is formed in the shaft center. A seal rubber 55 and a seal retainer 56 are attached between the fixing bolt 54 and the cord 47 to prevent leakage of cooling water from between the fixing bolt 54 and the cord 47.
Thereby, the distance b of the back plate 40 and the short side 39 can be measured for every position which installed each eddy current type displacement meter 41-43.
In addition, the displacement measuring method of the water-cooled copper plate according to the first embodiment of the present invention or the displacement measuring method of the water-cooled copper plate according to the second embodiment is the same as that of the water-cooled copper plate according to the third embodiment. It can also be combined with a displacement measurement method. That is, the distance a (a ′) of the back plate is measured with a first distance meter disposed on the back of the back plate, and the back plate and the long side or short side are measured with the second distance meter embedded in the back plate. By measuring the distance b to the side, the displacement of the long side or the short side can be obtained from the sum of the moving distance a (a ′) and the distance b.

Next, examples carried out for confirming the effects of the present invention will be described.
The used mold is a mold used in a conventionally known continuous casting machine.
As for the paired long sides constituting the mold, the side in contact with the upper surface side of the slab that is cast and conveyed downstream is referred to as the L side, and the side in contact with the lower surface side is referred to as the F side. Moreover, the short side which becomes a pair has a variable space | interval.
In the following embodiments, the short side on one side for changing the interval is referred to as the N side, and the short side on the other side is referred to as the S side.

In this mold, for the warpage deformation on the F side of the long side, three laser displacement meters are arranged on the back of the back plate arranged on the back side of the long side (see FIG. 1A), and FIG. As shown to (A), the displacement amount of the backplate was measured about three places, F1 point-F3 point, respectively. In addition, F1 point-F3 point are the upper part of a height direction, a center part, and a lower part in the width direction center part of a long side.
For warping deformation on the N side of the short side, three eddy current displacement meters are arranged on the back of the back plate arranged on the back side of the short side (see FIG. 1B), and FIG. As shown in FIG. 3, the displacement amount of the back plate was measured at three points N1 to N3. In addition, N1 point-N3 point are the upper part of a height direction, a center part, and a lower part in the width direction center part of a short side.
Moreover, the casting speed was performed about 1.0 m / min and 1.5 m / min. The transition of the casting speed is shown in FIG.

First, FIG. 5 shows the transition of warpage deformation on the F side for the back plate to which the long side is attached.
As is apparent from FIG. 5, it has been found that the displacement amount on the F side increases as the casting speed increases. On the L side, the amount of displacement was different from that on the F side, but a similar tendency was obtained.
Next, FIG. 6 shows the transition of warpage deformation on the N side for the back plate to which the short side is attached.
As is apparent from FIG. 6, it has been found that the displacement amount on the N side also increases as the casting speed increases. In addition, although the displacement amount also differs on the S side from the N side, substantially the same tendency was obtained.

Subsequently, plot points of warpage deformation in the casting direction on the F side for the back plate with the long side attached are plotted in FIG. 7, and plots of warpage deformation in the casting direction on the N side for the back plate with the short side attached. The points are shown in FIG. The meniscus position is a position 100 mm from the upper end of the mold.
“Vc” in FIGS. 7 and 8 is the casting speed of the slab (unit: “m / min”). 7 and 8 show the FEM analysis (analysis using the finite element method) in the case where the casting speed of the slab is 1.0 m / min (thick line) and 1.5 m / min (thin line). The deformation prediction results are also shown.

As is clear from FIG. 7, the difference between the F-side displacement amount and the upper end of the back plate and the central portion in the casting direction spread to about 0.5 mm. The FEM analysis result passed over the actual measurement value.
On the other hand, as shown in FIG. 8, it was found that the displacement amount on the N side was warped by about 1.2 mm.

As described above, when the long side or the short side is deformed integrally with the back plate by measuring the displacement amount of the back plate to which the long side or the short side is attached, the displacement amount of the back plate is The displacement amount is the long side or the short side. Further, when the long side or the short side is deformed with respect to the back plate, the displacement amount of the long side or the short side can be measured by using a distance meter embedded in the back plate.
Therefore, it was confirmed that the displacement amount of the long side and the short side can be measured by using the method for measuring the displacement of the water-cooled copper plate of the present invention.

Further, as described above, since the displacement amount of the long side and the short side can be estimated by FEM analysis, the thermal deformation distribution on the long side and the short side can be obtained by using this FEM analysis.
9 (A) and 10 (A) show the overall thermal deformation distribution on the F side and N side, and FIGS. 9 (B) and 10 (B) show the representative points on the F side and N side. The warp deformation distribution in the casting direction is shown respectively. In addition, a representative point is the position of the width direction center part of a long side or a short side, and the corner part of a long side or a short side for every casting speed (1.0 m / min, 1.5 m / min).

As shown in FIGS. 9A, 9B, 10A, and 10B, the thermal deformation distribution can be obtained for the long side and the short side. Based on this data, for example, By changing the casting conditions during continuous casting and performing shape processing of the water-cooled copper plate accompanying thermal deformation before continuous casting, the performance of the water-cooled copper plate taking into account the solidification profile of the slab can be sufficiently obtained, and good High quality cast slabs.

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included. For example, the case where the method for measuring the displacement of the water-cooled copper plate of the present invention is configured by combining some or all of the above-described embodiments and modifications is also included in the scope of the right of the present invention.
The structure of the mold is not limited to the structure shown in the embodiment as long as the back plate is disposed on the back side of the water-cooled copper plate. For example, a mold used in a conventionally known vertical bending type continuous casting machine or a mold used in a curved type continuous casting machine may be used.
Also, the mounting position of the laser displacement meter or eddy current displacement meter can be changed as necessary, and the number of mounting can be increased or decreased as necessary.
And in the said embodiment, although the case where the amount of displacement of the water-cooled copper plate which comprises both of a pair of short sides or both of a pair of long sides was measured was demonstrated, one of a pair of short sides or a pair of long sides Only one of the displacement amounts may be measured, or all the displacement amounts of the pair of short sides and the pair of long sides may be measured.

10: Space portion, 12: Molten steel, 13: Short side, 14: Long side, 15, 16: Back plate, 18: Mold frame, 19-21: Laser displacement meter (distance meter), 24-26: Eddy current Displacement meter (distance meter), 27: reference bar, 28, 29: support, 39: short side, 40: back plate, 41-43: eddy current displacement meter (distance meter), 44, 45: water guide groove , 46: O-ring, 47: Code, 48: Detection part, 49: Through hole, 50: Sensor head pressing part, 51, 52: O-ring, 53: Through hole, 54: Fixing bolt, 55: Seal rubber, 56: Seal presser

Claims (1)

A method for measuring the displacement of a water-cooled copper plate fixedly arranged inside a continuous casting mold,
A first distance meter is disposed on the back portion of the back plate disposed on the back side of the water-cooled copper plate, and the movement distance a of the back plate is measured by the first distance meter, and a second distance meter is disposed in the back plate. The distance b between the back plate and the water-cooled copper plate is measured by the second distance meter, and the displacement of the water-cooled copper plate is obtained from the sum of the moving distance a and the distance b. A method for measuring the displacement of a water-cooled copper plate.

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