CA1124485A - Method of increasing casting width for a slab during a continuous casting operation - Google Patents
Method of increasing casting width for a slab during a continuous casting operationInfo
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- CA1124485A CA1124485A CA331,317A CA331317A CA1124485A CA 1124485 A CA1124485 A CA 1124485A CA 331317 A CA331317 A CA 331317A CA 1124485 A CA1124485 A CA 1124485A
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- slab
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- narrow side
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Abstract
Abstract of the Disclosure The width of a slab can be easily increased during a continuous casting operation by a simple method, wherein casting of a molten steel is temporarily stopped during the continuous casting operation, the narrow side of a casting mold is moved to a predetermined width to form a space between the narrow side of the mold and the solidified shell of a slab, closing member and a cooling and sealing material are inserted into the space, and the casting of the molten steel is again started.
Description
4~85 The present invention relates to a method of increasing the casting width for a slab during a continuous casting operation, and particularly to a method of enlarging the width of a slab in an easy and safe manner during a very short period time of interruption of the continuous casting operation.
When a molten steel is formed into a slab through a continuous casting, the width of the slab is constant corresponding to the predetermined dimension of the casting mold. Therefore, when it is intended to produce slabs having different widths, the following procedure is generally carried out. That is, after a casting is completed, the resulting slab is drawn out, the set width of the casting mold is increased, a dummy bar is again inserted, and then the next casting is started. However, this procedure requires generally a long time of 1-2 hours until the next casting is started, after a casting is completed, the width of a casting mold is increased and then a dummy bar is inserted. This is one of the causes of decreasing the efficiency of continuous casting process.
It has been variously attempted to increase continuously the casting width in order to obviate the above described drawbacks without the reinsertion of a dummy bar.
For example, there has been known a method, wherein the narrow side of a casting mold is moved in such a very slow rate that does not cause breakage of a shell of slab formed by the solidification of molten steel in the casting mold.
However, in this method, it is necessary to move slowly the narrow side of a casting mold, and therefore a tapered slab is formed over several meters along the longitudinal direction ~Z~8S
of the slab in order to increase the slab width by several tens centimeters. This tapered slab has different widths along the longitudinal direction of the slab, and it is troublesome to produce a slab having a constant width by cutting off the tapered portion, and the yield is low. In another method illustrated in Fig. 1, casting is temporarily stopped, the narrow side 1 of a casting mold is moved backwardly by means of a driving gear 6, a plate 3 connected to another driving gear 2 arranged on the lower end of the narrow side 1 is moved forwardly, a cooling and sealing material 5 consisting of, for example, scrap is inserted in a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab, and then the casting is again started. However, this method has the following drawbacks. A high cost is required for arranging the above described devices at the lower end of the casting mold. A
cooling plate or a support roll, which is arranged on the lower end of a casting mold extending downwardly to several tens centimeters in order to hold a slab and to prevent the bulging of the slab in the ordinary continuous casting installation, can not be arranged in the apparatus of this method, and the slab is apt to bulge on the narrow side. As the result, the shape of the slab is poor, and cracks are apt to be formed on the surface or in the interior of the slab. Moreover, in this method, the plate 3 which supports the cooling and sealing material 5, must be moved backwardly means of the driving gear 2 just before the drawing out of the slab following to the casting. In this case, the cooling and sealing material 5 falls down the bottom portion of the solidified shell of a slab in the increased width portion is sometimes broken, and the molten steel breakouts. Further, there has been known a method, wherein a plate is arranged in a space between a previously moved narrow side of a casting mold and a slab, a molten steel is cast and then the slab is drawn out. However, in this method, the plate is apt to be deformed and moved due to the formation of mold taper and the oscillation movement at the drawing out of the slab, and there is a risk of breakout of the molten steel from the bottom of the increased portion of the slab.
The present invention aims to obviate the above described drawbacks and provides a method capable of increas-ing the width of a slab in a simple manner during the continuous casting operation.
That is, the feature of the present invention is the provision of a method of increasing the width of a slab in a continuous casting, comprising stopping temporarily casting of a molten steel during the continuous casting, moving the narrow side of a casting mold to a predetermined width to form a space between the narrow side of the casting mold and the solidified shell of the slab, inserting into the space a closing member provided with a suspender, which is engaged with the upper edge of the solidified shell, and a cooling and sealing material arranged on the closing member, and starting again the casting of the molten steel and the drawing out of the slab following to the casting.
The invention will now be described in greater detail with reference to the accompanying drawings, wherein:
Fig. 1 is a diagrammatic cross-sectional view for explaining a conventional method of increasing the casting width during a continuous casting operation as mentioned above;
Figs. 2a, 2b and 2c are diagrammatic cross-sectional views for explaining stepwisely the method of increasing the casting width according to the present invention during a continuous casting operation;
Figs. 3a and 3b are perspective views of closing members applicable to the method of the present invention;
and ; Figs. 4a and 4b are perspective views of slabs produced in the continuous casting method of the present invention and having different widths.
Figs. 2a 2b and 2c explain diagrammatically and stepwisely the method of increasing the casting width according to the present invention.
In Figs. 2a 2b and 2c, the numeral 1 represents the narrow side of a casting mold, the numeral 4 represents the solidified shell of a slab, the numeral 5 represents a cooling and sealing material, and the numeral 6 represents a driving gear for the narrow side of the casting mold. These members are the same as those used in the conventional method illustrated in Fig. 1. However, the method of the present invention is carried out without the use of a plate 3 and a driving gear 2 for the plate.
The space between the narrow side of the casting mold and the solidified shell of the slab must be filled with a certain means. The inventors have found a simple means for filling the space. As the result, the inventors have found a method not having the above described drawbacks and capable of increasing the width of a slab in a high workability and in a very simple manner with the use of the conventional continuous casting apparatus as such.
~2~ 5 The method of increasing the casting width of a slab during the continuous casting according to the present invention will be explained hereinafter referring to Figs.
2a-2c.
Fig. 2a illustrates a state of a casting mold - before the width thereof is enlarged in the conventional continuous casting. Fig. 2b illustrates a state of the casting mold, wherein the narrow sides of the mold are moved backwardly and a cooling and sealing material is filled in a ; 10 space between the narrow side of the mold and the solidified shell of a slab. Fig. 2c illustrates a state of the casting mold, wherein the casting is again started after the casting ; width of the mold has been increased.
In the state of casting a slab 9 having an original certain width illustrated in Fig. 2a, a molten steel charged in a turndish 7 is poured through a nozzle 8 into a casting mold formed by a pair of wide sides and a pair of narrow sides 1 and 1 arranged therebetween to produce the slab 9.
In Fig. 2a, the numeral 10 represents a support roll which supports the narrow side surface of the slab.
The casting is temporarily stopped in the state of Fig. 2a, and then the resulting slab is drawn out up to a position lower than the lower end of the nozzle, the narrow side 1 of the casting mold is moved backwardly up to a distance corresponding to a predetermined dimension of the - casting mold, a metal fitting for receiving a sealing material, that is, a closing member 11 illustrated in Fig. 3a or 3b, which consists of a metal plate 13 and metal rods 14 fixed thereto as a suspender, is inserted into a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab, -the metal rod 14 of the closing member 11 is engaged with the upper edge of the solidified shell 4 of the slab so as to suspend the closing member 11 therefrom, and then a cooling and sealing material 5 is filled in a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab as illustrated in Fig. 2b.
Then, the casting is again started as illustrated in Fig. 2c to produce a slab 12 having a width different from that of the originally cast slab 9.
In the present invention, the closing member 11 has a very important role. Therefore, the closing member 11 will be explained in detail hereinafter. The closing member 11 consists of a curved steel plate 13 having a semi-circular shape in cross-section and worked into a given dimension and round steel rods 14 having a diameter of about 5-30 mm and welded to the plate as illustrated in Fig. 3a in order that the rods 14 is engaged with the upper edge of the solidified shell 4 of a slab and suspends the steel plate. The width _ : 20 of the curved steel plate is preferred to be smaller by 1-5 mm than the width to be increased of the slab, and the length _ thereof is preferred to be narrower by 0-2 mm than the thickness of the slab. The reason is that a narrow gap is formed between the slab and the casting mold so that the slab can be smoothly drawn out even when a mold taper is formed and an oscillation movement occurs.
In the present invention, the above described round steel rod having a diameter of 5-30 mm is preferably used as the suspender 14. However, the suspender is not limited thereto, and a suspender having other shapes or made 4~S
of other materials can be used. For example, the suspender may be formed of a metal pipe or a refractory material.
Fig. 3b illustrates another embodiment of the closing member 11, wherein a flat steel plate 13 is used as the metal plate. The dimension of the flat steel plate illus-trated in Fig. 3b is the same as that of the curved steel plate illustrated in Fig. 3a. The closing member 11 can be made of not only steel but also metals other than steel and refractory materials.
The following examples are given for the purpose of illustration of this invention and are not intended as limitations thereof.
Exam_le 1 ~ raw material steel for casting a thick sheet, which contained 0.14% of C, 0.20% of Si, 0.80% of Mn and - other impurity elements, was firstly cast into a slab having a thickness of 200 mm and a width of 1,400 mm. During the course of the casting, the casting width for the slab was increased by 120 mm in each side, and a slab having a thickness of 200 mm and an width of 1,640 mm was produced ; successively.
In this Example, the slab having a width of 1,400 mm was firstly produced by a casting, the casting was temporarily stopped, each of the narrow sides of the casting mold was moved backwardly by 125 mm, a closing member 11 illustrated in Fig. 3a, which consisted of a curved steel plate 13 having a semi-circular shape in cross-section and ; having a width _ of 118 mm and a length n of 198 mm, and round steel rods 14 fixed to the plate 13 and having a diameter of 20 mm and a length of 200 mm was suspended from ~ ~ 2'~ 5 the upper edge of each narrow side of the solidified shell 4 of a slab 9, and then each narrow side o-f the casting mold was moved forwardly by 5 mm, whereby the casting width of the mold was increased in both narrow sides thereof so as to produce the slab having a thickness of 200 mm and an increased width of 1,640 mm. Then, a cooling and sealing material 5 consisting of nail scrap was filled up to a height of about 100 mm in spaces between the solidified shell 4 of the slab 9 and the narrow sides of the casting mold, and casting of the raw material steel from the turndish 7 was again started.
lt tooks about 90 seconds in the above described operation. The slab width was increased stepwisely in the same manner as described above, and three kinds of slabs ; having different widths were produced by merely inserting originally a dummy bar. Fig. 4a illustrates the seam of the slab 9 having an original width and the slab 12 having an increased width in both sides produced in this Example.
Example 2 A raw material steel for casting a cold rolled ; 20 steel sheet, which contained 0.04% of C, 0.30% of Mn, 0.035%
of AQ and other impurity elements, was firstly cast into a slab having a thickness of 260 mm and a width of 960 mm.
During the course of the casting, the casting width for the slab was increased by 80 mm in only one side, and a slab having a thickness of 260 mm and a width of 1,040 mm was produced successively.
In this Example, the slab having a width of 960 mm was firstly produced by a casting, the casting was temporarily stopped, only one of the narrow sides 1 and 1 of the casting mold was moved backwardly by about 85 mm, a closing member 11 4 ~5 illustrated in Fig. 3b, which consisted of a flat steel plate 13 having a thickness of 5 mm, a width _ of 78 mm and a length n of 258 mm and round steel rods 14 having a diameter of 15 mm and a length of 200 mm and fixed thereto, was suspended from the upper edge of the short side of the solidified shell 4 of the slab 9, which was faced to the backwardly moved narrow side of the casting mold, and the backwardly moved narrow side of the casting mold was moved forwardly by about 5 mm, whereby the casting width of the mold was increased in one narrow side thereof so as to produce a slab having a thickness of 260 mm and a width of 1,040 mm. Then, a cooling and sealing material 5 consisting of nail scrap was filled up to a height of about 100 mm in a space between the solidified shell 4 of the slab 9 and the narrow side 1 of the casting mold, and the casting of the raw material steel from the turndish 7 was again started.
It tooks about 75 seconds in the above described operation. The slab width was increased stepwisely in the same manner as described above, and four kinds of slabs having different widths were produced by merely inserting originally a dummy bar. Fig. 4b illustrates the seam of the slab 9 having an original width and the slab 12' having an increased width in one side produced in this Example.
Example 3 A raw material steel for casting a thick sheet, which contained 0.13% of C, 0.18% of Si, 0.75% of Mn and other impurity elements, was firstly cast into a slab having a thickness of 200 mm and a width of 1,600 mm. During the course of the casting, the casting width for the slab was increased by 200 mm in only one side, and a slab having a thickness of 200 mm and a width of 1,800 mm was produced successively.
In this Example, the slab having a width of 1,600 mm was firstly produced by a casting, the casting was ` 5 temporarily stopped, only one of the narrow sides 1 and 1 ofthe casting mold was moved backwardly by 200 mm, and a closing member 11 illustrated in Fig. 3a, which consisted of a curved steel plate 13 having a semi-circular shape in cross-section and having a width _ of 195 mm and a length _ of 198 mm and round steel rods 14 having a diameter of 20 mm and a length of 200 mm and fixed to the plate 13, was suspended from the upper edge of the narrow side of the solidified shell 4 of the slab 9, which was faced to the backwardly moved narrow side of the casting mold, whereby the - 15 casting width of the mold was increased in one narrow side thereof so as to produce a slab having a thickness of 200 mm and a width of 1,800 mm. Then, a cooling and sealing ` material 5 consisting of nail scrap was filled up to a height of about 100 mm in a space between the solidified shell 4 of the slab 9 and the narrow side 1 of the casting : mold, and the casting from the turndish 7 was again started.
~, As described above, according to the present invention, a conventional casting installation is directly used, and the width of a slab can be increased stepwisely in a simple manner by the use of an easily available material and by stopping the casting for several minutes.
In the continuous casting method, the operation efficiency can not be improved mainly due to the reason that casting is stopped in every casting lot, the width of the ~ J~ 5 casting mold is increased and then a dummy bar is again inserted. This operation requires 1-2 hours. On the contrary, in the present invention, the time required for this operation can be omitted, and the operation efficiency of the continuous casting installation is remarkably increased, and further the tapered slab is not formed at all. Therefore, the yield in the continuous casting accord-ing to the present invention is higher by 0.5-2% than the yield in the conventional continuous casting. Moreover, according to the present invention, since a large amount of raw material steel can be continuously cast by one time of insertion of a dummy bar, the amount of refractory material to be used for the turndish is 20-40% smaller than that in the conventional continuous casting. Further, according to the present invention, slabs composed of different kinds of steels and having different widths can be produced by a continuous casting.
.~ .
.
When a molten steel is formed into a slab through a continuous casting, the width of the slab is constant corresponding to the predetermined dimension of the casting mold. Therefore, when it is intended to produce slabs having different widths, the following procedure is generally carried out. That is, after a casting is completed, the resulting slab is drawn out, the set width of the casting mold is increased, a dummy bar is again inserted, and then the next casting is started. However, this procedure requires generally a long time of 1-2 hours until the next casting is started, after a casting is completed, the width of a casting mold is increased and then a dummy bar is inserted. This is one of the causes of decreasing the efficiency of continuous casting process.
It has been variously attempted to increase continuously the casting width in order to obviate the above described drawbacks without the reinsertion of a dummy bar.
For example, there has been known a method, wherein the narrow side of a casting mold is moved in such a very slow rate that does not cause breakage of a shell of slab formed by the solidification of molten steel in the casting mold.
However, in this method, it is necessary to move slowly the narrow side of a casting mold, and therefore a tapered slab is formed over several meters along the longitudinal direction ~Z~8S
of the slab in order to increase the slab width by several tens centimeters. This tapered slab has different widths along the longitudinal direction of the slab, and it is troublesome to produce a slab having a constant width by cutting off the tapered portion, and the yield is low. In another method illustrated in Fig. 1, casting is temporarily stopped, the narrow side 1 of a casting mold is moved backwardly by means of a driving gear 6, a plate 3 connected to another driving gear 2 arranged on the lower end of the narrow side 1 is moved forwardly, a cooling and sealing material 5 consisting of, for example, scrap is inserted in a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab, and then the casting is again started. However, this method has the following drawbacks. A high cost is required for arranging the above described devices at the lower end of the casting mold. A
cooling plate or a support roll, which is arranged on the lower end of a casting mold extending downwardly to several tens centimeters in order to hold a slab and to prevent the bulging of the slab in the ordinary continuous casting installation, can not be arranged in the apparatus of this method, and the slab is apt to bulge on the narrow side. As the result, the shape of the slab is poor, and cracks are apt to be formed on the surface or in the interior of the slab. Moreover, in this method, the plate 3 which supports the cooling and sealing material 5, must be moved backwardly means of the driving gear 2 just before the drawing out of the slab following to the casting. In this case, the cooling and sealing material 5 falls down the bottom portion of the solidified shell of a slab in the increased width portion is sometimes broken, and the molten steel breakouts. Further, there has been known a method, wherein a plate is arranged in a space between a previously moved narrow side of a casting mold and a slab, a molten steel is cast and then the slab is drawn out. However, in this method, the plate is apt to be deformed and moved due to the formation of mold taper and the oscillation movement at the drawing out of the slab, and there is a risk of breakout of the molten steel from the bottom of the increased portion of the slab.
The present invention aims to obviate the above described drawbacks and provides a method capable of increas-ing the width of a slab in a simple manner during the continuous casting operation.
That is, the feature of the present invention is the provision of a method of increasing the width of a slab in a continuous casting, comprising stopping temporarily casting of a molten steel during the continuous casting, moving the narrow side of a casting mold to a predetermined width to form a space between the narrow side of the casting mold and the solidified shell of the slab, inserting into the space a closing member provided with a suspender, which is engaged with the upper edge of the solidified shell, and a cooling and sealing material arranged on the closing member, and starting again the casting of the molten steel and the drawing out of the slab following to the casting.
The invention will now be described in greater detail with reference to the accompanying drawings, wherein:
Fig. 1 is a diagrammatic cross-sectional view for explaining a conventional method of increasing the casting width during a continuous casting operation as mentioned above;
Figs. 2a, 2b and 2c are diagrammatic cross-sectional views for explaining stepwisely the method of increasing the casting width according to the present invention during a continuous casting operation;
Figs. 3a and 3b are perspective views of closing members applicable to the method of the present invention;
and ; Figs. 4a and 4b are perspective views of slabs produced in the continuous casting method of the present invention and having different widths.
Figs. 2a 2b and 2c explain diagrammatically and stepwisely the method of increasing the casting width according to the present invention.
In Figs. 2a 2b and 2c, the numeral 1 represents the narrow side of a casting mold, the numeral 4 represents the solidified shell of a slab, the numeral 5 represents a cooling and sealing material, and the numeral 6 represents a driving gear for the narrow side of the casting mold. These members are the same as those used in the conventional method illustrated in Fig. 1. However, the method of the present invention is carried out without the use of a plate 3 and a driving gear 2 for the plate.
The space between the narrow side of the casting mold and the solidified shell of the slab must be filled with a certain means. The inventors have found a simple means for filling the space. As the result, the inventors have found a method not having the above described drawbacks and capable of increasing the width of a slab in a high workability and in a very simple manner with the use of the conventional continuous casting apparatus as such.
~2~ 5 The method of increasing the casting width of a slab during the continuous casting according to the present invention will be explained hereinafter referring to Figs.
2a-2c.
Fig. 2a illustrates a state of a casting mold - before the width thereof is enlarged in the conventional continuous casting. Fig. 2b illustrates a state of the casting mold, wherein the narrow sides of the mold are moved backwardly and a cooling and sealing material is filled in a ; 10 space between the narrow side of the mold and the solidified shell of a slab. Fig. 2c illustrates a state of the casting mold, wherein the casting is again started after the casting ; width of the mold has been increased.
In the state of casting a slab 9 having an original certain width illustrated in Fig. 2a, a molten steel charged in a turndish 7 is poured through a nozzle 8 into a casting mold formed by a pair of wide sides and a pair of narrow sides 1 and 1 arranged therebetween to produce the slab 9.
In Fig. 2a, the numeral 10 represents a support roll which supports the narrow side surface of the slab.
The casting is temporarily stopped in the state of Fig. 2a, and then the resulting slab is drawn out up to a position lower than the lower end of the nozzle, the narrow side 1 of the casting mold is moved backwardly up to a distance corresponding to a predetermined dimension of the - casting mold, a metal fitting for receiving a sealing material, that is, a closing member 11 illustrated in Fig. 3a or 3b, which consists of a metal plate 13 and metal rods 14 fixed thereto as a suspender, is inserted into a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab, -the metal rod 14 of the closing member 11 is engaged with the upper edge of the solidified shell 4 of the slab so as to suspend the closing member 11 therefrom, and then a cooling and sealing material 5 is filled in a space between the narrow side 1 of the casting mold and the solidified shell 4 of the slab as illustrated in Fig. 2b.
Then, the casting is again started as illustrated in Fig. 2c to produce a slab 12 having a width different from that of the originally cast slab 9.
In the present invention, the closing member 11 has a very important role. Therefore, the closing member 11 will be explained in detail hereinafter. The closing member 11 consists of a curved steel plate 13 having a semi-circular shape in cross-section and worked into a given dimension and round steel rods 14 having a diameter of about 5-30 mm and welded to the plate as illustrated in Fig. 3a in order that the rods 14 is engaged with the upper edge of the solidified shell 4 of a slab and suspends the steel plate. The width _ : 20 of the curved steel plate is preferred to be smaller by 1-5 mm than the width to be increased of the slab, and the length _ thereof is preferred to be narrower by 0-2 mm than the thickness of the slab. The reason is that a narrow gap is formed between the slab and the casting mold so that the slab can be smoothly drawn out even when a mold taper is formed and an oscillation movement occurs.
In the present invention, the above described round steel rod having a diameter of 5-30 mm is preferably used as the suspender 14. However, the suspender is not limited thereto, and a suspender having other shapes or made 4~S
of other materials can be used. For example, the suspender may be formed of a metal pipe or a refractory material.
Fig. 3b illustrates another embodiment of the closing member 11, wherein a flat steel plate 13 is used as the metal plate. The dimension of the flat steel plate illus-trated in Fig. 3b is the same as that of the curved steel plate illustrated in Fig. 3a. The closing member 11 can be made of not only steel but also metals other than steel and refractory materials.
The following examples are given for the purpose of illustration of this invention and are not intended as limitations thereof.
Exam_le 1 ~ raw material steel for casting a thick sheet, which contained 0.14% of C, 0.20% of Si, 0.80% of Mn and - other impurity elements, was firstly cast into a slab having a thickness of 200 mm and a width of 1,400 mm. During the course of the casting, the casting width for the slab was increased by 120 mm in each side, and a slab having a thickness of 200 mm and an width of 1,640 mm was produced ; successively.
In this Example, the slab having a width of 1,400 mm was firstly produced by a casting, the casting was temporarily stopped, each of the narrow sides of the casting mold was moved backwardly by 125 mm, a closing member 11 illustrated in Fig. 3a, which consisted of a curved steel plate 13 having a semi-circular shape in cross-section and ; having a width _ of 118 mm and a length n of 198 mm, and round steel rods 14 fixed to the plate 13 and having a diameter of 20 mm and a length of 200 mm was suspended from ~ ~ 2'~ 5 the upper edge of each narrow side of the solidified shell 4 of a slab 9, and then each narrow side o-f the casting mold was moved forwardly by 5 mm, whereby the casting width of the mold was increased in both narrow sides thereof so as to produce the slab having a thickness of 200 mm and an increased width of 1,640 mm. Then, a cooling and sealing material 5 consisting of nail scrap was filled up to a height of about 100 mm in spaces between the solidified shell 4 of the slab 9 and the narrow sides of the casting mold, and casting of the raw material steel from the turndish 7 was again started.
lt tooks about 90 seconds in the above described operation. The slab width was increased stepwisely in the same manner as described above, and three kinds of slabs ; having different widths were produced by merely inserting originally a dummy bar. Fig. 4a illustrates the seam of the slab 9 having an original width and the slab 12 having an increased width in both sides produced in this Example.
Example 2 A raw material steel for casting a cold rolled ; 20 steel sheet, which contained 0.04% of C, 0.30% of Mn, 0.035%
of AQ and other impurity elements, was firstly cast into a slab having a thickness of 260 mm and a width of 960 mm.
During the course of the casting, the casting width for the slab was increased by 80 mm in only one side, and a slab having a thickness of 260 mm and a width of 1,040 mm was produced successively.
In this Example, the slab having a width of 960 mm was firstly produced by a casting, the casting was temporarily stopped, only one of the narrow sides 1 and 1 of the casting mold was moved backwardly by about 85 mm, a closing member 11 4 ~5 illustrated in Fig. 3b, which consisted of a flat steel plate 13 having a thickness of 5 mm, a width _ of 78 mm and a length n of 258 mm and round steel rods 14 having a diameter of 15 mm and a length of 200 mm and fixed thereto, was suspended from the upper edge of the short side of the solidified shell 4 of the slab 9, which was faced to the backwardly moved narrow side of the casting mold, and the backwardly moved narrow side of the casting mold was moved forwardly by about 5 mm, whereby the casting width of the mold was increased in one narrow side thereof so as to produce a slab having a thickness of 260 mm and a width of 1,040 mm. Then, a cooling and sealing material 5 consisting of nail scrap was filled up to a height of about 100 mm in a space between the solidified shell 4 of the slab 9 and the narrow side 1 of the casting mold, and the casting of the raw material steel from the turndish 7 was again started.
It tooks about 75 seconds in the above described operation. The slab width was increased stepwisely in the same manner as described above, and four kinds of slabs having different widths were produced by merely inserting originally a dummy bar. Fig. 4b illustrates the seam of the slab 9 having an original width and the slab 12' having an increased width in one side produced in this Example.
Example 3 A raw material steel for casting a thick sheet, which contained 0.13% of C, 0.18% of Si, 0.75% of Mn and other impurity elements, was firstly cast into a slab having a thickness of 200 mm and a width of 1,600 mm. During the course of the casting, the casting width for the slab was increased by 200 mm in only one side, and a slab having a thickness of 200 mm and a width of 1,800 mm was produced successively.
In this Example, the slab having a width of 1,600 mm was firstly produced by a casting, the casting was ` 5 temporarily stopped, only one of the narrow sides 1 and 1 ofthe casting mold was moved backwardly by 200 mm, and a closing member 11 illustrated in Fig. 3a, which consisted of a curved steel plate 13 having a semi-circular shape in cross-section and having a width _ of 195 mm and a length _ of 198 mm and round steel rods 14 having a diameter of 20 mm and a length of 200 mm and fixed to the plate 13, was suspended from the upper edge of the narrow side of the solidified shell 4 of the slab 9, which was faced to the backwardly moved narrow side of the casting mold, whereby the - 15 casting width of the mold was increased in one narrow side thereof so as to produce a slab having a thickness of 200 mm and a width of 1,800 mm. Then, a cooling and sealing ` material 5 consisting of nail scrap was filled up to a height of about 100 mm in a space between the solidified shell 4 of the slab 9 and the narrow side 1 of the casting : mold, and the casting from the turndish 7 was again started.
~, As described above, according to the present invention, a conventional casting installation is directly used, and the width of a slab can be increased stepwisely in a simple manner by the use of an easily available material and by stopping the casting for several minutes.
In the continuous casting method, the operation efficiency can not be improved mainly due to the reason that casting is stopped in every casting lot, the width of the ~ J~ 5 casting mold is increased and then a dummy bar is again inserted. This operation requires 1-2 hours. On the contrary, in the present invention, the time required for this operation can be omitted, and the operation efficiency of the continuous casting installation is remarkably increased, and further the tapered slab is not formed at all. Therefore, the yield in the continuous casting accord-ing to the present invention is higher by 0.5-2% than the yield in the conventional continuous casting. Moreover, according to the present invention, since a large amount of raw material steel can be continuously cast by one time of insertion of a dummy bar, the amount of refractory material to be used for the turndish is 20-40% smaller than that in the conventional continuous casting. Further, according to the present invention, slabs composed of different kinds of steels and having different widths can be produced by a continuous casting.
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Claims (5)
1. A method of increasing the width of a slab during a continuous casting operation, comprising stopping temporarily casting of a molten steel during the continuous casting, moving the narrow side of a casting mold to a predetermined width to from a space between the narrow side of the casting mold and the solidified shell of the slab, inserting into the space a closing member provided with a suspender, which is engaged with the upper edge of the solidified shell, and a cooling and sealing material arranged on the closing member, and starting again the casting of the molten steel and the drawing out of the slab following to the casting.
2. A method according to claim 1, wherein said closing member consists of a metal plate and metal rods fixed thereto as the suspender.
3. A method according to claim 2, wherein said metal plate is a curved steel plate having a semi-circular shape in cross-section or a flat steel plate and said metal rod is a steel rod.
4. A method according to claim 2, wherein said metal plate has a width 1-5 mm smaller than the width to be increased of the slab and a length 0-2 mm shorter than the thickness of the slab.
5. A method according to claim 3, wherein said steel rod is a round steel rod having a diameter of 5-30 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA331,317A CA1124485A (en) | 1979-07-06 | 1979-07-06 | Method of increasing casting width for a slab during a continuous casting operation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA331,317A CA1124485A (en) | 1979-07-06 | 1979-07-06 | Method of increasing casting width for a slab during a continuous casting operation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1124485A true CA1124485A (en) | 1982-06-01 |
Family
ID=4114631
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA331,317A Expired CA1124485A (en) | 1979-07-06 | 1979-07-06 | Method of increasing casting width for a slab during a continuous casting operation |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1124485A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112916813A (en) * | 2019-12-05 | 2021-06-08 | 上海梅山钢铁股份有限公司 | Method for accurately selecting scrap iron material for continuous casting safety seal dummy ingot |
-
1979
- 1979-07-06 CA CA331,317A patent/CA1124485A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112916813A (en) * | 2019-12-05 | 2021-06-08 | 上海梅山钢铁股份有限公司 | Method for accurately selecting scrap iron material for continuous casting safety seal dummy ingot |
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