JP4300796B2 - Solidified state detector for continuous cast slabs - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for detecting a solidified state of a slab by continuously penetrating ultrasonic waves in the thickness direction of a continuously cast slab.
[0002]
[Prior art]
In general, continuous casting of molten metal is performed by injecting molten metal from a tundish into a mold having a predetermined cross-sectional shape, and continuously pulling out a slab mixed with a molten part and a solidified part from below the mold. ing. Immediately after being drawn out of the mold, the slab occupies most of the inner part of the melted portion which is not solidified, but as the solidification proceeds by subsequent cooling, the proportion of the solidified portion increases, and the whole Solidify.
[0003]
Here, it is very important to determine where the fully solidified end (crater end) of the continuous cast slab is located in the slab in the continuous drawing process. The reason is as follows.
That is, when the casting speed is increased in order to improve productivity, the crater end moves to the downstream side of the slab. If the position of the crater end moves downstream beyond the cutting position by the slab cutter, there is a possibility of a major accident such as molten steel leakage.
[0004]
Further, in the light reduction operation for reducing the center segregation of solidification and improving the quality, it is necessary to control the casting speed and the secondary cooling amount so that the crater end is positioned in the vicinity of the light reduction zone. In order to meet these requirements, it is necessary to continuously measure the solidification state of the slab.
[0005]
Thus, since detecting the position of the crater end and detecting the solidified state of the slab greatly contributes to the improvement in the productivity and quality of the slab, various devices have been developed.
For example, a spacer roller that rolls in contact with the slab surface and a water-cooled electromagnetic ultrasonic transducer with a cooling water jet hole face each other centering on the slab and prevents the pulling of the transducer in contact with the measured object transport roller An electromagnetic ultrasonic measurement apparatus provided with a support roller has been proposed (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
Japanese Examined Patent Publication No. 2-646 [0007]
[Problems to be solved by the invention]
However, the above prior art has the following problems.
In order to maintain a predetermined distance between the cold electromagnetic ultrasonic transducer and the slab, a spacer roller is provided at the tip of the cold electromagnetic ultrasonic transducer so as to roll over the slab. However, since the slab surface is not a smooth surface, the cold electromagnetic ultrasonic transducer may be drawn into the guide roller. However, in Patent Document 1, in order to avoid this pull-in phenomenon, a pull-in prevention support roller that rolls in contact with the measured object transport roller is provided. However, as long as there is a mechanical contact, there is a risk of pull-in, vibration, or the like. There is a risk of erroneous detection.
[0008]
The present invention has been made to solve such a problem, and the sensor and its holding part are completely in non-contact with the slab, so that there is no risk of pull-in or malfunction due to vibration or the like. It aims at obtaining the coagulation state detection apparatus.
[0009]
[Means for Solving the Problems]
The solidification state detection device for a continuous cast slab according to the present invention draws the molten steel injected into the mold below the mold, and in the thickness direction of the slab continuously cast while cooling in the cooling zone, An apparatus that detects the solidification state of the slab by penetrating ultrasonic waves from a non-contact transmission sensor and receiving ultrasonic waves transmitted through the slab by a non-contact reception sensor. ,
A linear rail installed in the direction perpendicular to the direction of travel of the slab on the outside of the chamber of the cooling zone, a linear guide installed so as to be able to run on the linear rail, and sandwiched between the slab attached to the linear guide A pair of arms arranged vertically, and
The linear guide is provided on the rear end side of the arm so that the front side of the arm can extend greatly from the linear rail, and a balance weight is provided on the rear end side of the arm,
The transmission sensor is attached, and when the slab comes into contact with the transmission sensor and an external force is applied, an emergency shock absorber for moving the transmission sensor in a direction away from the slab is provided on one of the pair of arms. Installed at the tip of the arm,
When the receiving sensor is attached and an external force is applied to the receiving sensor due to the slab contacting the receiving sensor, an emergency shock absorber for moving the receiving sensor away from the slab is provided on the other side of the pair of arms. It is installed at the tip of the arm.
[0011]
In addition, the emergency shock absorber includes a support bar installed at the tip of the arm;
Wherein the sensor holding portion installed movably in a direction away from the slab to the distal end side of the support rod, and biasing means for normally urging the side cast the sensor holding portion, in that it comprises an Is.
[0012]
In addition, a cooling water nozzle for injecting cooling water to the slab is provided at the tip of the arm.
Further, the transmission sensor and the reception sensor have a water cooling structure.
[0013]
Further, a transmission-side cooling water nozzle and a reception-side cooling water nozzle for injecting cooling water to each surface of the slab are provided at the tip of the arm, and the transmission-side cooling water nozzle and the reception-side cooling water nozzle A cooling water pipe is connected to each,
The transmission sensor and the reception sensor have a water cooling structure, and a cooling water pipe is connected to each of the transmission sensor and the reception sensor,
Each of the cooling water pipes is connected to a header and provided with a water amount adjusting valve, and is configured to be able to adjust the water amount separately.
[0014]
6. The continuous cast slab according to claim 1, wherein the pair of arms are configured such that the upper and lower sides sandwiching the slab are independent of each other, and each arm is configured to be position-adjustable. Coagulation state detection device.
[0015]
Further, the pair of arms has a C shape in which the rear end sides are connected, and a plurality of linear rails are provided in parallel.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a schematic side view showing the entire continuous casting machine. FIG. 2 is an enlarged view of the circled portion of FIG. 1 and shows the configuration of the signal processing system of the solidification state detection device of the present embodiment. ing. FIG. 3 is a side view of the solidification state detection device of the present embodiment, and FIG. 4 is a plan view. First, the overall description of the continuous casting machine and the outline of the signal processing system will be described based on FIGS. 1 and 2, and then the configuration of the solidification state detection device will be described in detail based on FIGS. 3 and 4. .
[0017]
In the continuous casting machine, as shown in FIG. 1, the molten steel transferred from the ladle 1 to the tundish 3 and from the tundish 3 to the mold 5 is installed in a guide roll apron 6 provided below the mold 5. The slab 9 is manufactured by transferring between a plurality of sets of support rolls 7.
The slab 9 immediately after being drawn out from the mold 5 occupies most of the inner side of the melted portion 9a that is not solidified, but as the solidification proceeds by subsequent cooling, the proportion of the solidified portion increases. The whole solidifies.
[0018]
In order to determine in which position of the slab 9 the fully solidified end (crater end (see FIG. 2)) of the slab 9 is located, a solidified state detection device 11 is installed.
As shown in FIG. 2, the signal processing system of the coagulation state detection device 11 includes a transmission transverse wave electromagnetic ultrasonic sensor 13 (hereinafter simply referred to as “transmission sensor 13”) and a reception transverse wave electromagnetic ultrasonic sensor 15 (hereinafter simply referred to as “transmission sensor 13”). , “Sensor 15 for reception”), a transmission output system (arbitrary waveform generator 19, transmission amplifier 21) that outputs a transmission signal to the transmission sensor 13, and the reception sensor 15. A reception processing system (reception amplifier 23, filter 25, oscilloscope 27) for processing the reception signal and a crater end calculator 29 for calculating a crater end and a slab solidification state based on the reception signal are provided.
[0019]
Next, the configuration of the coagulation state detection device will be described in detail with reference to FIGS. In FIG. 3, a solid line indicates a standby state, and a broken line indicates a detection execution state.
The solidification state detection device 11 according to the present embodiment includes a lower-side device frame 31 installed outside the chamber 31 in the cooling zone, and a linear rail installed on the lower-side device frame 31 in a direction orthogonal to the traveling direction of the slab 9. 33, a plurality of linear guides 35 traveling on the linear rail 33, and a narrow arm 37 attached to the linear guide 35. FIG. 5 shows a state in which the relationship between the linear rail 33, the linear guide 35, and the arm 37 is viewed from the rear.
[0020]
The reason why the arm 37 is made narrow is that the arm 37 can be inserted between the guide rolls 7. In order to insert the arm 37 between the guide rolls 7, a linear guide 35 that supports the arm 37 is provided on the rear end side of the arm 37, and the front side of the arm 37 can be extended from the linear rail 33. Yes. A balance weight 39 is provided on the rear end side of the arm 37 in order to eliminate the unbalance caused by the linear guide 35 that supports the arm 37 not being located at the center of the arm 37.
A transmission sensor 13 is attached to the distal end side of the arm 37.
[0021]
An upper apparatus frame 43 is mounted on the lower apparatus frame 31 via an elevating device 41, and the height of the upper apparatus frame 43 can be freely adjusted by the elevating device 41. Similar to the lower apparatus frame 31 described above, a linear rail 45, a linear guide 47, and an arm 49 are installed in the upper apparatus frame 43. A receiving sensor 15 is attached to the front end side of the arm 49, and a balance weight 51 is attached to the rear end side.
[0022]
In the present embodiment, since the upper and lower arms 37 and 49 have separate structures, the position of each arm can be adjusted and fine adjustment can be performed.
The arms 37 and 49 are configured so that the linear guides 35 and 47 run on the linear rails 33 and 45 by the drive motor 53 shown in FIG. . The movement of the arms 37 and 49 is performed by the linear guides 35 and 47, so that smooth running is realized. As a result, the transmission / reception sensors 13 and 15 attached to the tips of the arms 37 and 49 are in a non-contact state. Can be held.
[0023]
The transmission sensor 13 transmits a transmission signal as a transverse electromagnetic ultrasonic wave, and the reception sensor 15 receives a transmission signal obtained by transmitting the electromagnetic ultrasonic wave through the slab 9. At this time, the position of the crater end is detected by processing the received signal with the above-described signal processing system by utilizing the fact that the transverse ultrasonic wave cannot propagate in the residual molten metal that is in the liquid phase.
[0024]
FIG. 6 is an enlarged view of the distal end portion of the solidification state detection device 11, and is an enlarged view of a state (detectable state) in which the sensors 13 and 15 are arranged with the slab 9 interposed therebetween. Based on FIG. 6, the structure of the front-end | tip part of the coagulation | solidification state detection apparatus 11 is demonstrated. Since the upper side and the lower side have the same structure, description will be given by taking the upper side as an example. However, the same reference numerals are given to the parts corresponding to the upper side structure.
[0025]
First, the mounting structure of the receiving sensor 15 will be described.
The receiving sensor 15 is attached to an emergency shock absorber 55 that can move in a direction away from the slab 9 when the receiving sensor 15 receives an external force. The emergency shock absorber 55 includes four support rods 57, 59, 61, 63 installed downward at the tip of the arm 49, and the cast piece 9 on the tip side of the support rods 57, 59, 61, 63. A holding member 65 is provided so as to be movable in a direction away from it, and a leg portion 67 attached to the slab 9 side of the holding member 65, and the receiving sensor 15 is attached to the leg portion 67.
[0026]
The compression springs 69 and 71 are fitted on the outer circumferences of the two outer support rods 57 and 63 of the four support rods 57, 59, 61 and 63, and the compression springs 69 and 71 are held. The member 65 is constantly urged toward the slab 9 side. For this reason, the holding member 65 is always pressed against the slab 9 and disposed at a predetermined position, whereby the gap between the receiving sensor 15 and the slab 9 is defined at a predetermined interval.
When the receiving sensor 15 comes into contact with the convex portion on the surface of the slab 9 and an external force acts on the receiving sensor 15, the holding member 65 moves away from the slab 9 against the urging force of the compression springs 69 and 71. Move in the direction. For this reason, excessive force does not act on the receiving sensor 15, and the receiving sensor 15 is not caught and destroyed.
[0027]
Next, the cooling structure of the receiving sensor 15 and the cast piece 9 will be described.
The reception sensor 15 has a water cooling structure, and a cooling water pipe 73 provided along the arm 49 is also connected to the reception sensor 15. A cooling nozzle 75 for injecting cooling water to the slab 9 is provided at the tip of the arm 49, and a cooling pipe 77 provided along the arm 49 is connected to the cooling nozzle 75. Yes. As shown in FIGS. 6 to 8, the cooling nozzle 75 can inject cooling water to the rear of the slab 9 in the traveling direction, that is, immediately before the receiving sensor 15 detection unit.
[0028]
Thus, since the cooling nozzle 75 for cooling the slab 9 is provided at the tip of the arm 49, even if the arm 49 is moved, only a necessary portion can be cooled and the amount of cooling water can be saved.
[0029]
The cooling water for cooling the receiving sensor 15 and the cooling water supplied to the cooling nozzle 75 are supplied from the cooling water main pipe 79 by the respective cooling pipes 73 and 75 through the header 81 as shown in FIG. The The cooling pipes 73 and 75 are provided with flow rate adjusting valves 83 and 85, respectively.
Thus, by providing the flow rate adjusting valves 83 and 85 separately for the respective cooling pipes 73 and 75, a predetermined amount of cooling water is always received without being affected by the fluctuation of the cooling water quantity of the cooling water main pipe 79. The sensor 15 and the cooling nozzle 75 can be supplied.
[0030]
Here, an effect of being able to always supply a predetermined amount of cooling water to the receiving sensor 15 and the cooling nozzle 75 will be described. As a premise, a problem when the amount of cooling water supplied to the receiving sensor 15 and the cooling nozzle 75 fluctuates will be described.
First, when the amount of cooling water in the reception sensor 15 decreases, the sensitivity decreases due to heating of the reception sensor 15. Conversely, when the amount of cooling water in the receiving sensor 15 increases, vibration due to the cooling water becomes noise and the sensitivity decreases.
[0031]
Further, when the amount of cooling water to the cooling nozzle 75 is reduced, the cooling efficiency of the slab 9 is deteriorated, and the transmittance of ultrasonic waves is deteriorated. In addition, the heat load on the sensor increases, and the durability of the sensor decreases. Conversely, when the amount of cooling water increases, the water jetted from the cooling nozzle 75 enters a jet jet state, causing vibrations in the cooling nozzle 75 and the receiving sensor 15 and adversely affecting the sensitivity.
[0032]
As described above, when the amount of cooling water supplied to the receiving sensor 15 and the cooling nozzle 75 fluctuates, various problems occur. In the present embodiment, a predetermined amount of cooling water can always be supplied to the receiving sensor 15 and the cooling nozzle 75. Therefore, such a problem does not occur.
[0033]
In order to detect the solidification state of the slab 9 by the solidification state detection device 11 configured as described above, the transmission / reception sensors 13 and 15 are aligned before the casting starts, and the arms 37 and 49 are moved after the casting starts. It is inserted between the guide rolls (the state of the broken line in FIG. 3), and the lift-off amount (the gap amount between the sensors 13 and 15 and the slab 9) is adjusted so that the sensor sensitivity is good.
When the lift-off amount can be adjusted, the arms 37 and 49 are moved to scan the slab 9 in the width direction by the sensors 13 and 15.
At this time, the transmission sensor 13 transmits the transmission signal as a transverse electromagnetic ultrasonic wave, and the reception sensor 15 receives a transmission signal obtained by transmitting the electromagnetic ultrasonic wave through the slab 9. The position of the crater end is detected by processing this received signal with the signal processing system described above.
[0034]
When there is a change in the light reduction amount of the continuous casting machine or a change in the thickness of the cast piece 9, the lift-off amount is changed accordingly.
[0035]
In the present embodiment, the sensors 13 and 15 are installed at the distal ends of the arms 37 and 49 so that the solidified state of the slab 9 can be detected in a non-contact manner. The solidification state of the slab 9 can be accurately detected without any trouble.
Further, since the arms 37 and 49 have a vertically divided structure, the position can be adjusted for each arm, and the lift-off amount can be set accurately.
Further, since the sensors 13 and 15 are attached via the emergency shock absorber 55, when the sensors 13 and 15 receive an external force, the sensors 13 and 15 can move in a direction away from the slab 9, and the sensor is caught up. , And can prevent destruction.
[0036]
Further, since the cooling nozzle 75 for cooling the slab 9 is provided at the tip of the arm, even if the arm 49 is moved, only a necessary portion can be cooled, and the amount of cooling water can be saved.
In addition, since the flow rates to the sensors 13 and 15 and the cooling nozzle 75 can be adjusted separately, the amount of cooling water to the sensors 13 and 15 and the cooling nozzle 75 can always be controlled to a predetermined amount, and the sensitivity of the sensors 13 and 15 is good. Can be kept in.
[0037]
Further, by retracting the arms 37 and 49, the arm tip is disposed outside the chamber 31, so that maintenance of the entire apparatus including the sensors 13 and 15 can be facilitated.
[0038]
Embodiment 2. FIG.
FIG. 10 is an explanatory diagram of the second embodiment of the present invention. The same reference numerals are given to the same parts as those of the first embodiment shown in FIG.
In this embodiment, the upper and lower arms are integrated into a C-shaped arm 87. By doing so, the structure of the arm can be simplified. However, since the rail is arranged only in the lower part and the standing end of the C-shaped arm 87 becomes high, there is a risk of falling to the left and right. Therefore, in this embodiment, as shown in FIG. 11, two rails are installed in parallel at positions separated by a predetermined distance. By doing in this way, falling of the arm to the left and right can be prevented.
[0039]
【The invention's effect】
As described above, in the present invention, the linear rail installed in the direction perpendicular to the traveling direction of the slab on the outside of the chamber of the cooling zone, the linear guide installed to be able to run on the linear rail, and the linear guide A pair of arms that are attached and arranged above and below the slab, a transmission sensor installed at one tip of the pair of arms, and installed at the other tip of the pair of arms Since the sensor and the arm tip are not in contact with the upper and lower surfaces of the slab, the slab 9 is accurately solidified without being affected by irregularities on the surface of the slab. Can be detected.
[Brief description of the drawings]
FIG. 1 is a schematic side view showing an entire continuous casting machine according to an embodiment of the present invention.
FIG. 2 is an enlarged view of a portion surrounded by a circle in FIG. 1;
FIG. 3 is a side view of a coagulation state detection apparatus according to an embodiment of the present invention.
FIG. 4 is a plan view of a coagulation state detection apparatus according to an embodiment of the present invention.
FIG. 5 is a partially enlarged view of a coagulation state detection apparatus according to an embodiment of the present invention.
FIG. 6 is a partially enlarged view of the coagulation state detection apparatus according to the embodiment of the present invention.
FIG. 7 is a partially enlarged view of a coagulation state detection apparatus according to an embodiment of the present invention.
FIG. 8 is a partially enlarged view of a coagulation state detection apparatus according to an embodiment of the present invention.
FIG. 9 is a system diagram of cooling water piping of the solidification state detection device according to the embodiment of the present invention.
FIG. 10 is a side view of a coagulation state detection device according to another embodiment of the present invention.
FIG. 11 is a partially enlarged view of a coagulation state detection device according to another embodiment of the present invention.
[Explanation of symbols]
13 Transmission sensor 15 Reception sensor 31 Cooling zone chamber 33 Linear rail 35 Linear guide 37 Arm 39 Balance weight 55 Emergency buffer 75 Cooling nozzle 83, 85 Flow rate adjusting valve 87 C-type arm

Claims (7)

The molten steel injected into the mold is drawn below the mold, and the slab is continuously cast while being cooled in the cooling zone. An apparatus for detecting the solidification state of the slab by receiving ultrasonic waves transmitted through the slab with a receiving sensor in a non-contact state,
A linear rail installed in the direction perpendicular to the direction of travel of the slab on the outside of the chamber of the cooling zone, a linear guide installed so as to be able to run on the linear rail, and sandwiched between the slab attached to the linear guide A pair of arms arranged vertically, and
The linear guide is provided on the rear end side of the arm so that the front side of the arm can extend greatly from the linear rail, and a balance weight is provided on the rear end side of the arm,
The transmission sensor is attached, and when the slab comes into contact with the transmission sensor and an external force is applied, an emergency shock absorber for moving the transmission sensor in a direction away from the slab is provided on one of the pair of arms. Installed at the tip of the arm,
When the receiving sensor is attached and an external force is applied to the receiving sensor due to the slab contacting the receiving sensor, an emergency shock absorber for moving the receiving sensor away from the slab is provided on the other side of the pair of arms. An apparatus for detecting a solidification state of a continuous cast slab, wherein the solid state detection apparatus is installed at a tip of an arm. The emergency shock absorber includes a support bar installed at the tip of the arm;
A sensor holding portion installed on the front end side of the support bar so as to be movable away from the slab, and a biasing means for constantly urging the sensor holding portion toward the slab side. The solidification state detection apparatus of the continuous cast slab of Claim 1.   The solid state detection device for a continuous cast slab according to claim 1 or 2, wherein a cooling water nozzle for injecting cooling water to the slab is provided at a tip of the arm.   The solidification state detection device for a continuous cast slab according to any one of claims 1 to 3, wherein the transmission sensor and the reception sensor have a water cooling structure. A transmitting-side cooling water nozzle and a receiving-side cooling water nozzle for injecting cooling water to each surface of the slab are provided at the tip of the arm, and the transmitting-side cooling water nozzle and the receiving-side cooling water nozzle are respectively provided to The cooling water pipe is connected,
The transmission sensor and the reception sensor have a water cooling structure, and a cooling water pipe is connected to each of the transmission sensor and the reception sensor,
The solidification state detection of the continuous cast slab according to claim 1 or 2, wherein each of the cooling water pipes is connected to a header and is provided with a water amount adjusting valve so that the water amount can be adjusted separately. apparatus.   The solidification of the continuous cast slab according to any one of claims 1 to 5, wherein the pair of arms are configured so that the upper and lower sides sandwiching the slab are independent of each other and each arm is configured to be position-adjustable. State detection device.   The pair of arms are formed in a C shape in which the rear end sides are connected, and a plurality of linear rails are provided in parallel. The solidified state of the continuous cast slab according to any one of claims 1 to 6 Detection device.

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