JPH0732110A - Method for cutting off cast slab - Google Patents

Abstract

PURPOSE:To provide a method of making the cut-off waste length at the last casting part in a continuously cast slab absolutely min. CONSTITUTION:In this method, a cast slab length measuring machine 3 for measuring the cut-off length of the continuously cast slab, a cast slab run out detector 6 for the last casting part arranged at the position at a fixed distance from the length measuring machine 3 at the upstream side from the cutter 4 and a computer 7 for grasping instructed cut-off length, measured uncut-off cast slab length and the cut-off length in the last casting part are provided and used. The necessarily minimum cut-off waste length 1T at the last casting part is found to be cut from the 1Y from the cast slab run out detector 6 to the length measuring machine 3 and the length 1X of the continuously cast slab 2 being measured presently with the length measuring machine 3 when the last casting part passes through the cast slab run out detector 6. In this way, the cut-off waste cast slab length generated at the last casting part in the continuous casting is made to necessary minimum the aggravation of the yield caused by scraping of the good cast slab and the increase of working load due to recutting at the regulating yard, etc., are eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slab cutting length to minimize the slab cutting length when carrying out slab cutting of a final casting part of a continuous slab manufactured by a continuous casting machine. The present invention relates to a slab cutting method for determining the height.

[0002]

2. Description of the Related Art A block for preventing molten steel from leaking into a continuous casting machine during drawing is filled in a final casting portion that occurs when casting is completed in a continuous casting operation, or molten steel is not supplied. Since coagulation is completed, shrinkage cavities occur.

Therefore, as for the final solidification part, the part which is considered not to affect the product is cut off depending on the operation method or quality restrictions.

Further, in the cutting operation of continuous casting, a specified length of a cast piece to be sampled, an instruction for producing a cast piece such as a permissible range, a planned cutting length determined based on the instruction, and a cut-off of the final cast portion. Values such as length are displayed as cold length. On the other hand, the continuous cast piece is cut in a hot piece state.

Therefore, when performing the cut calculation of continuous cast pieces, the length of the continuous cast pieces in the hot state is multiplied by a predetermined heat shrinkage coefficient to convert the cold length, and the cold length is displayed. Generally, it is compared with the length of the manufacturing instruction etc.

By the way, the following method has been conventionally adopted as a method for determining the cutting length when cutting the cut-off portion by using the cutting equipment of the continuous casting machine.

Since the final slab is in the mold when the casting is completed, the equipment length from the slab length measuring machine to the end of the final casting part in the vicinity of the mold is known in advance, and when the casting is completed, The equipment length and the length of the continuous cast piece being measured by the length measuring machine are summed up, and the value obtained by multiplying this length by a predetermined heat shrinkage coefficient is taken as the total length in cold conversion of the uncut continuous cast piece. The cut length of the final cast part, which is displayed as the cold length, is subtracted from the total continuous cast piece length converted to cold, and the remaining continuous cast piece length is compared with the cold-produced cast piece manufacturing instruction, and multiple cast pieces are cast. There was a method of deciding the expected cut length.

[0008]

As mentioned above, it is general to insert a block for preventing molten steel leakage into the final casting part, but for that purpose, the drawing speed is temporarily reduced and the block is completed. After that, the drawing speed is increased to pull out the continuous cast pieces in the continuous casting machine at high speed.

Since such operations are carried out, the contraction amount of the continuous cast piece having a length of several tens of meters from the mold to the cutting machine varies, and the cutting is performed according to the planned cutting length at the end of casting. If it continues, excess and deficiency will occur in the required cutting length when cutting the final casting part.

Therefore, when the cut-off length of the final casting part is longer than the manufacturing instruction, the yield is deteriorated due to scrapping of good cast pieces, and when it is short, the work load is increased due to re-cutting in a refinement yard or the like. Was there.

Therefore, the present invention solves the above problems and provides a slab cutting method for determining the slab cutting length so that the cut length of the final casting part is minimized when cutting the final casting part. .

[0012]

DISCLOSURE OF THE INVENTION The present invention which solves the above-mentioned problems includes a slab length measuring machine for measuring the length of a continuous cast slab to be cut, and an upstream side of the cutting machine and the length measuring machine. A slab slip-out detector that is installed at a fixed distance to detect that the slab in the final casting part has slipped out, and a slab such as the cold slab length and the allowable range of the slab to be manufactured With a basic configuration having a manufacturing instruction, a planned cutting length of the continuous cast piece, a continuous cast piece length in cold conversion captured by the length measuring machine, and a cut-off length of the final cast portion in the cold state It achieves the optimization of the length of the cut slab required for the final casting part.

[0013]

When the final casting portion of the continuous cast piece passes the cast piece trailing edge detector, the detection signal is transmitted to the computer.

On the computer side, at the time of receiving the tail slipping completion signal, the length of the continuous cast piece between the cast piece tail slipping detector and the length measuring machine and the hot strip currently measured by the length measuring machine. Sum the measured length of and.

This total length is the total length of the hot-cut uncut continuous slab, and by multiplying this total length by a predetermined heat shrinkage coefficient, the uncut portion on the delivery side of the trailing edge slip detector is detected. The total length of cold-cut continuous cast pieces in cold equivalent can be grasped.

From the total length of the cold-cut uncut continuous cast piece,
The cut-off length of the final casting portion given by the cold length is subtracted, and the remaining cold-converted continuous cast piece length and the planned cut length in the cold display are compared in size.

Here, if the length of the remaining continuous cast piece and the planned cutting length match, cutting is performed according to the planned length, and if the two lengths are different, the planned cutting length is the total length. By replacing the cut length of the final cast with the continuous cast length, the precision of the cut length required for the final cast is improved.

The slab slip-out detector may be a mechanical detector in which a striker is brought into direct contact with the slab, or a light emitting / receiving type detector using light rays.

By using a detector having a linear light source such as a laser beam, the accuracy of the length of the uncut slab can be further improved.

[0020]

EXAMPLE FIG. 1 is a view showing a cutting condition of a cast piece at the end of casting.

At the end of casting, the distance l _X from the slab length measuring device 3 to the tip of the continuous cast slab and the distance l _Y from the slab length measuring device 3 to the final casting part in the mold 1 are summed, and these are calculated. Total length of l _x
By multiplying + l _Y by a predetermined slab heat shrinkage coefficient, the overall length L _X + L _Y of the continuous cast slab 2 in cold conversion is obtained, and the final casting part, which is the cold length, is cut off from this overall length. Subtract the length L _T.

By comparing the contents of L _X + L _Y -L _T with the ingot production instruction, the expected cutting length of a plurality of ingots and the expected cutting length l _{1 of the} final ingot T ₁ are planned. The slab cutting up to this point has been carried out conventionally.

In addition to the conventional method described above, this method
Immediately before the cutting machine 4, the length of the uncut slab is grasped again, the error of the heat shrinkage of the slab is minimized, and the operator checks the residual length of the uncut slab or performs manual intervention such as length correction. It is characterized in that the cut-off length L _T of the final cast portion can be cut without any necessary minimum length.

FIG. 2 shows an embodiment of this method. The basic configuration of this method is a slab length measuring machine that measures the length of the continuous slab to be cut,
A slab slippage detector 6 for detecting a slab slippage in the final casting part, which is installed on the upstream side of the cutting machine and at a constant distance from the length measuring machine, a manufacturing instruction of the slab, and a continuous cast piece cutting a length and said captured by length measuring machine continuously cast strip length and the final casting of the truncated length L _T and knows the computer 7 Doo.

In this embodiment, the cast piece tail drop detection 6 is made possible by a light emitting and receiving type detector such as a laser.

Until the final casting portion passes, the light of the detector is blocked by the continuous cast piece 2, and the final casting portion detection signal a is transmitted to the computer 7 at the moment when the final casting portion passes therethrough.

FIG. 3 shows a processing flow in the computer 7. A slab manufacturing instruction is input to the computer 7 in advance.

When the casting is completed, the mold 1 is cut to the cutting machine 4
The length of L _X + L _Y , which is the total length of the uncut continuous cast piece 2 in the cold equivalent existing between the two, is grasped, and the expected cutting length of the final cast piece T ₁ is determined based on the length and the content of the cast piece manufacturing instruction. L ₁ will be scheduled.

Next, when the final casting portion slips out of the slab trailing edge detector 6, a slab trailing edge signal a is transmitted to the computer 7.

The computer 7 receives the casting tail trailing-out signal a and receives the distance l _X from the casting length measuring machine 3 to the end of the continuous casting piece.
And the distance l _Y from the slab length measuring machine 3 to the final casting part are summed up to obtain a total continuous slab length l _z in the hot state at the time when the slab slippage is detected.

This l _Z is multiplied by a predetermined heat shrinkage coefficient to obtain the cold length L _Z of the uncut continuous cast piece on the exit side of the cast piece slip-out detector 6.

The cut-off length L _T of the final casting portion is subtracted from this L _Z to determine whether L _Z -L _T is equal to the expected cutting length L _{1 of the} final cast T ₁ .

When the lengths of both are equal, the slab length measuring machine 3
When the cold-converted measurement length of ₁ corresponds to L ₁ , the cutting command signal C is transmitted from the computer 7 to the cutting machine control panel 8.

The planned cutting length L₁And L_Z− L_TDifferent from
Planned cutting length L₁To L_Z− L_TReplaced with
The cold conversion measurement length of the slab length measuring machine 3 is L_Z− L_TMatched with
At this time, the cutting command signal G is sent from the computer 7 to the cutting control panel 8.
Send. Due to the above processing, it is necessary for the final casting part.
The precision of the length of cut-out cast slab is improved.

Although the distance l _Y between the slab length measuring machine 3 and the slab slippage detector 6 should be made as small as possible, the heat shrinkage error of the slab can be made smaller, but After detecting, the time for determining whether or not the expected cutting length L ₁ is appropriate is required. Therefore, it is only necessary to determine l _Y from the maximum casting speed and the time required for this determination.

[0036]

EFFECTS OF THE INVENTION By applying the present invention, the length of cut-off slab generated in the final casting part in the continuous casting can be minimized to a minimum, and the yield is deteriorated due to scrapping of good slabs, and in the finishing yard, etc. The increase in work load due to the re-cutting is eliminated.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a slicing condition of a slab at the time of completion of casting.

FIG. 2 is an explanatory view showing an example of the cast slab of the present invention.

FIG. 3 is a processing flow chart in the computer of the present invention.

[Explanation of symbols]

 1 mold 2 continuous cast piece 3 cast piece length measuring machine 4 cutting machine 5 cutting completed cast piece 6 cast piece tail dropout detector 7 calculator 8 cutting machine control panel a cast piece tail dropout signal b cast piece length measurement value c cutting command signal T₁ Final slab T₂ One slab before the final slab T₃ Two slabs before the final slab 1_T Final casting part cut length during hot work l_X Distance from hot slab length gauge to end of continuous slab  l_Y Distance from hot slab length gauge to final casting part l_Z With the hot slab dropout detector,
All uncut slab length when lit₁ Planned cutting length of final slab during hot work l₂ Planned cutting length of the front slab of the final slab 1₃ Planned cutting length of the two slabs before the final slab during hot working  l_Four The difference between the hot cutting point and the actual target point L_T Cold cut length of final casting part L_X Distance from cold slab length gauge to the end of continuous cast slab L_Y Distance from cold slab length measuring machine to final casting part L_Z The slab dropout detector in the cold is used to detect the slab dropout.
All uncut slab length L₁ Planned cutting length of final slab in cold state L₂ Planned cutting length of the ingot before the final ingot in the cold state L₃ Planned cutting length of the front two slabs of the final slab in the cold state L_Four Difference between planned cold cutting point and actual target point

Front page continuation (72) Inventor Masafumi Kawaguchi 1 Fuji-machi, Hirohata-ku, Himeji City Nippon Steel Corporation Stock company Hirohata Works

Claims (1)

[Claims] 1. A slab length measuring machine for measuring a length of a continuous slab to be cut when cutting a slab of a final casting part cast by a continuous casting machine, and a slab length measuring machine upstream of the slicing machine. With a cast slab slip-out detector that detects the cast slab slip-out of the final casting part installed at a position that is a constant distance from the long machine, the manufacturing instruction of the cast piece and the planned cutting length of the continuous cast piece and the length measuring machine Equipped with a calculator that grasps the captured continuous cast piece length and the cut-off length of the final casting part, and when the final casting part passes the cast piece tail slipping detector, from the cast piece tail slipping detector to the length measuring machine And the length of the continuous cast piece currently measured by the length measuring machine are summed, and the length of the continuous cast piece obtained by subtracting the cut-off length of the final casting part from this total length is compared with the planned cutting length. If the two lengths are different, cut the planned cutting length from the above total length and cut off the final casting part. A cast piece cutting method, characterized in that the cast piece is cut with the cast piece cut length in the final casting portion being minimized by replacing the length with a continuous cast piece length.