CA1162600A - Electromagnetic stirrer in a continuous steel casting plant - Google Patents
Electromagnetic stirrer in a continuous steel casting plantInfo
- Publication number
- CA1162600A CA1162600A CA000355376A CA355376A CA1162600A CA 1162600 A CA1162600 A CA 1162600A CA 000355376 A CA000355376 A CA 000355376A CA 355376 A CA355376 A CA 355376A CA 1162600 A CA1162600 A CA 1162600A
- Authority
- CA
- Canada
- Prior art keywords
- stirrer
- casting
- dummy bar
- guide
- path
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000005266 casting Methods 0.000 title claims abstract description 57
- 229910000831 Steel Inorganic materials 0.000 title claims description 9
- 239000010959 steel Substances 0.000 title claims description 9
- 230000002844 continuous effect Effects 0.000 abstract 1
- 238000001816 cooling Methods 0.000 description 4
- 230000036961 partial effect Effects 0.000 description 4
- 238000009749 continuous casting Methods 0.000 description 2
- 239000000696 magnetic material Substances 0.000 description 2
- 238000005452 bending Methods 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/08—Accessories for starting the casting procedure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/12—Accessories for subsequent treating or working cast stock in situ
- B22D11/122—Accessories for subsequent treating or working cast stock in situ using magnetic fields
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
- Manufacture Of Alloys Or Alloy Compounds (AREA)
Abstract
ABSTRACT
An electromagnetic stirrer installed in a conti-nuous stelle casting plant at a distance from the casting path, whereby the stirrer is provided with a guide device on its side facing the casting path for guiding a flexible dummy bar. In this way the dummy bar, which on account of its degree of play in the casting guide may possibly swing into the stirrer, is kept away from direct access to the structurally relatively weak side of the stirrer which could result in damage. Furthermore the dummy bar is so guided as to avoid undesirable collision between the dummy bar head and guide rollers.
An electromagnetic stirrer installed in a conti-nuous stelle casting plant at a distance from the casting path, whereby the stirrer is provided with a guide device on its side facing the casting path for guiding a flexible dummy bar. In this way the dummy bar, which on account of its degree of play in the casting guide may possibly swing into the stirrer, is kept away from direct access to the structurally relatively weak side of the stirrer which could result in damage. Furthermore the dummy bar is so guided as to avoid undesirable collision between the dummy bar head and guide rollers.
Description
~16~6~0 The invention relates to ~n eJectromagnetic stirrer in a continuous steel casting plant, in which the stirrer is installed at a distance rom the casting path.
In the continuous cas-ting of steel, electromagnetic stirrers in the secondary cooling zone are intended to effect an accelerated dissipation o overheating by producing a flow in the liquid casting core, produce a globulitic (equiaxed) solidification structure in the middle of the casting, and pro-duce a uniform distribution over the casting cross-section of steel companion elements tending to form segregations. In order to keep electrical losses as low as possible, the stirrer must be mounted with its working face as far as possible in the immediate vicinity of the casting surface, as is the case in plants having a suficiently large distance between successive support guidest and the stirrer front plate and surrounding parts of the plant must be manufactured from a non-magnetic material.
In order for the stirrer front plate to be as close as possible to the casting surace in the case of relatively small distances between the guide rollers, it is known to make the upper and lower parts of the stirrer bevelled or tapered in the casting direction so that additional rollers oE relatively small radius can be mounted in the free space between the bevelling and the next largest guide roller. These small rollers produce equally large guide roller interspacings in the stirrer region as well, whereby comparatively large, unsupported hot casting sections can be avoided. However, it has been found in practice that the guidance in the stirrer region is not suf-ficient when introducing a flexible dummy bar having a relatively short head and short chain links. The very small thickness of the dummy bar and the resultant degree of play between '$~$' 6~0 oppositely located guide rollers may result, in the region of the small rollers in the immediate vicinity of the stirrer, in deflections or drifting of the dummy bar and in particular may result in a tipping of the dummy bar head onto the stlrrer.
The result is that the dummy bar strikes against or becomes wedged on the small rollers, leading to breakdowns and damage, and also rubs against and strikes the stirrer from plate, resulting in damage to the stirrer.
The ob~ect of the present invention is, when introducing a flexible dummy bar from above or below into the casting guide of a continuous steel casting plant, to protect on the one hand an electromagnetic stirrer and on the other hand rollers of the casting guide possibly present in the immediate vicinity of the stirrer against chemical damage leading to interruptions in the casting operation.
According to the present invention, there is provided an electromagnetic stirrer in a continuous steel casting plant, in which the stirrer is installed at a distance from the casting path, one side of the stirrer facing the casting path, and wherein a dummy bar is introduced into a casting guide, characterized in that the side of the stirrer facing the casting path is provided with a guide device for the dummy bar, arranged at a distance from the casting path.
In this way a dummy bar, which on account of its degree i of play in the casting guide may possibly swing into the stir-rer, is kept away from direct access to the structurally rela-tively weak front plate, which could result in damage. The dummy bar is guided so that an undesirable collision between the dummy bar and the guide rollers is largely a~oided.Because the guide device is designed in such a way that it is arranged at a distance from the casting path,i.e. does not normally contact the casting surface during casting, non-uniform !
6~
cooling of the casting surface is avoided and a metallurgi-cally uniform casting product is guaranteed.
In one preferred embodiment the guide device consists of at least one rail. This runs in the cas-ting path direction.
The embodiment is structurally inexpensive, results in only a slight additional weight, and can easily be combined with the front plate to form a single unit. This solution may prefe-rably be employed with relatively light dummy bars in the case of billet plants and fairly small cogged ingot plants having widely spaced apart guide elements. With wider dummy bars, a plurality of guide rails may also be employed as required.
In another preferred embodiment of the invention the guide device may consist of a reinforced stirrer front plate.
Preferably, the guide device has in the running direction of the introduced dummy bar, end pieces directed towards the casting path. By means of this robust embodiment heavier dummy bars of fairly large cogged ingot sizes and also fairly large slab sizes, should they be inadvertently deflected or 20 drift, can also be guided in the stirrer region, and damage to the stirrer coils arranged immediately behind the front plate or to adjacent casting guide rollers, caused by external forces, is avoided.
The invention is described, with the aid of examples, in the diagrammatically drawings, in which:
Fig.l shows in partial side view the introduction of a dummy bar from below into a cogged ingot plant with an installed stirrer with a reinforced front ¦ plate, and Fig.2 shows in partial plan view a stirrer with a front plate having guide rails.
~16:~6~)0 Fig. 1 shows, in partial side vlew, a sec-tion of a secondary cooling zone of a continuous casting plant for cogged ingots. For the sake of clarity, details of the plant that are unimportant for the understanding of the invention, such as the mould, spray nozzles, drive unit, arc radius,etc., - /
- /
f . ~ -3a-~6;;26~0 have been omi~t~d. An arrow 2 in~ic~tes the casting direction in the plant. Pairs of oppositely situated guide rollers 1, 1' define the intended casting paths 3, 3', shown by the chain-dotted lines. The rollers 1 guide the outer curved surface and the rollers 1' the inner curved surace of a hot casting, not illustrated. A partially illustrated electromagnetic stirrer 4, whose side 23 faces the casting path 3, is installed between the successive inner curved guide rollers 1' in the casting direction 2. The reinforced front plate 5 of the stirrer 4 is formed as a guide device for the dummy bar 9, and is secured to the stirrer housing 7 by means of countersunk bolts 6. The front plate is made of a non-magnetic material, e.g. austenitic steel; and is of such a thickness and strength that it prevents bending and denting, and thus damage, to the sensitive stirrer coil 8 situated therebehind, caused by a drifting flexible dummy bar 9 during its introduction. The dummy bar 9 is introduced in this example from below, as illustrated by the arrow ~0, against the casting direction 2.
The dummy bar head 11 is movably hinged on the dummy bar 9, whereby a tipping ef~ect away from the casting path 3, in par- -ticular as shown here, may occur in the case of casting guides with widely spaced apart guide elements 1, 1'. In order to prevent too great a deflection, in the region between the guide rollers 1' and lower and upper edges of the stirrer, of the - dummy bar 9 guided in the casting path with a degree of play 14, the front plate 5 has at the top and bottom outwardly and inwardly bent end pieces 12, serving as a guide for the dummy bar. In this way there is prevented any tipping or canting of the dummy bar chain and in addition any collision of the dummy bar head with the stirrer or the roller 1' situated above and below. In plants in which the dummy bar is introduced from ~16;Z6~10 above, these end pi~ces 12 are o~ course bent in the opposite direction. As can be seen from the diagramf the stirrer fron~
plate is at a certain distance 13 from the inner curved, intended casting path 3 or casting path boundary, with the result that a sufficient degree of cooling is ensured over the whole hot casting region facing the stirrer 4, during the casting procedure. The stirrer 4 can of course also be mounted on the outer curved side or on two opposite sides of the casting.
Fig. 2 shows another embodiment of the invention in a par-tial plan view. An electromagnetic stirrer 15 acts over a dis-tance 16 on a casting billet 17, shown partially in cross-section. A front plate l9 of non-magnetic steel is welded to the stirrer housing 18 on the working side of the stirrer 15.
The stirrer coil 20 is situated behind this front plate l9.
Guide devices for the dummy bar in the form of rails 21 are mounted on the front plate l9 f which orm a rigid unit with the latter and are at a distance 22 ~rom the billet surface.
These rails 21 may also be extended along the casting path above and below the stirrer housing 18 to the vicinity of the next casting guide element in order to ensure a satisfactory guidance of the dummy bar. The rails 21 may be bent at their ends so as to prevent the dummy bar becoming wedged.
In the continuous cas-ting of steel, electromagnetic stirrers in the secondary cooling zone are intended to effect an accelerated dissipation o overheating by producing a flow in the liquid casting core, produce a globulitic (equiaxed) solidification structure in the middle of the casting, and pro-duce a uniform distribution over the casting cross-section of steel companion elements tending to form segregations. In order to keep electrical losses as low as possible, the stirrer must be mounted with its working face as far as possible in the immediate vicinity of the casting surface, as is the case in plants having a suficiently large distance between successive support guidest and the stirrer front plate and surrounding parts of the plant must be manufactured from a non-magnetic material.
In order for the stirrer front plate to be as close as possible to the casting surace in the case of relatively small distances between the guide rollers, it is known to make the upper and lower parts of the stirrer bevelled or tapered in the casting direction so that additional rollers oE relatively small radius can be mounted in the free space between the bevelling and the next largest guide roller. These small rollers produce equally large guide roller interspacings in the stirrer region as well, whereby comparatively large, unsupported hot casting sections can be avoided. However, it has been found in practice that the guidance in the stirrer region is not suf-ficient when introducing a flexible dummy bar having a relatively short head and short chain links. The very small thickness of the dummy bar and the resultant degree of play between '$~$' 6~0 oppositely located guide rollers may result, in the region of the small rollers in the immediate vicinity of the stirrer, in deflections or drifting of the dummy bar and in particular may result in a tipping of the dummy bar head onto the stlrrer.
The result is that the dummy bar strikes against or becomes wedged on the small rollers, leading to breakdowns and damage, and also rubs against and strikes the stirrer from plate, resulting in damage to the stirrer.
The ob~ect of the present invention is, when introducing a flexible dummy bar from above or below into the casting guide of a continuous steel casting plant, to protect on the one hand an electromagnetic stirrer and on the other hand rollers of the casting guide possibly present in the immediate vicinity of the stirrer against chemical damage leading to interruptions in the casting operation.
According to the present invention, there is provided an electromagnetic stirrer in a continuous steel casting plant, in which the stirrer is installed at a distance from the casting path, one side of the stirrer facing the casting path, and wherein a dummy bar is introduced into a casting guide, characterized in that the side of the stirrer facing the casting path is provided with a guide device for the dummy bar, arranged at a distance from the casting path.
In this way a dummy bar, which on account of its degree i of play in the casting guide may possibly swing into the stir-rer, is kept away from direct access to the structurally rela-tively weak front plate, which could result in damage. The dummy bar is guided so that an undesirable collision between the dummy bar and the guide rollers is largely a~oided.Because the guide device is designed in such a way that it is arranged at a distance from the casting path,i.e. does not normally contact the casting surface during casting, non-uniform !
6~
cooling of the casting surface is avoided and a metallurgi-cally uniform casting product is guaranteed.
In one preferred embodiment the guide device consists of at least one rail. This runs in the cas-ting path direction.
The embodiment is structurally inexpensive, results in only a slight additional weight, and can easily be combined with the front plate to form a single unit. This solution may prefe-rably be employed with relatively light dummy bars in the case of billet plants and fairly small cogged ingot plants having widely spaced apart guide elements. With wider dummy bars, a plurality of guide rails may also be employed as required.
In another preferred embodiment of the invention the guide device may consist of a reinforced stirrer front plate.
Preferably, the guide device has in the running direction of the introduced dummy bar, end pieces directed towards the casting path. By means of this robust embodiment heavier dummy bars of fairly large cogged ingot sizes and also fairly large slab sizes, should they be inadvertently deflected or 20 drift, can also be guided in the stirrer region, and damage to the stirrer coils arranged immediately behind the front plate or to adjacent casting guide rollers, caused by external forces, is avoided.
The invention is described, with the aid of examples, in the diagrammatically drawings, in which:
Fig.l shows in partial side view the introduction of a dummy bar from below into a cogged ingot plant with an installed stirrer with a reinforced front ¦ plate, and Fig.2 shows in partial plan view a stirrer with a front plate having guide rails.
~16:~6~)0 Fig. 1 shows, in partial side vlew, a sec-tion of a secondary cooling zone of a continuous casting plant for cogged ingots. For the sake of clarity, details of the plant that are unimportant for the understanding of the invention, such as the mould, spray nozzles, drive unit, arc radius,etc., - /
- /
f . ~ -3a-~6;;26~0 have been omi~t~d. An arrow 2 in~ic~tes the casting direction in the plant. Pairs of oppositely situated guide rollers 1, 1' define the intended casting paths 3, 3', shown by the chain-dotted lines. The rollers 1 guide the outer curved surface and the rollers 1' the inner curved surace of a hot casting, not illustrated. A partially illustrated electromagnetic stirrer 4, whose side 23 faces the casting path 3, is installed between the successive inner curved guide rollers 1' in the casting direction 2. The reinforced front plate 5 of the stirrer 4 is formed as a guide device for the dummy bar 9, and is secured to the stirrer housing 7 by means of countersunk bolts 6. The front plate is made of a non-magnetic material, e.g. austenitic steel; and is of such a thickness and strength that it prevents bending and denting, and thus damage, to the sensitive stirrer coil 8 situated therebehind, caused by a drifting flexible dummy bar 9 during its introduction. The dummy bar 9 is introduced in this example from below, as illustrated by the arrow ~0, against the casting direction 2.
The dummy bar head 11 is movably hinged on the dummy bar 9, whereby a tipping ef~ect away from the casting path 3, in par- -ticular as shown here, may occur in the case of casting guides with widely spaced apart guide elements 1, 1'. In order to prevent too great a deflection, in the region between the guide rollers 1' and lower and upper edges of the stirrer, of the - dummy bar 9 guided in the casting path with a degree of play 14, the front plate 5 has at the top and bottom outwardly and inwardly bent end pieces 12, serving as a guide for the dummy bar. In this way there is prevented any tipping or canting of the dummy bar chain and in addition any collision of the dummy bar head with the stirrer or the roller 1' situated above and below. In plants in which the dummy bar is introduced from ~16;Z6~10 above, these end pi~ces 12 are o~ course bent in the opposite direction. As can be seen from the diagramf the stirrer fron~
plate is at a certain distance 13 from the inner curved, intended casting path 3 or casting path boundary, with the result that a sufficient degree of cooling is ensured over the whole hot casting region facing the stirrer 4, during the casting procedure. The stirrer 4 can of course also be mounted on the outer curved side or on two opposite sides of the casting.
Fig. 2 shows another embodiment of the invention in a par-tial plan view. An electromagnetic stirrer 15 acts over a dis-tance 16 on a casting billet 17, shown partially in cross-section. A front plate l9 of non-magnetic steel is welded to the stirrer housing 18 on the working side of the stirrer 15.
The stirrer coil 20 is situated behind this front plate l9.
Guide devices for the dummy bar in the form of rails 21 are mounted on the front plate l9 f which orm a rigid unit with the latter and are at a distance 22 ~rom the billet surface.
These rails 21 may also be extended along the casting path above and below the stirrer housing 18 to the vicinity of the next casting guide element in order to ensure a satisfactory guidance of the dummy bar. The rails 21 may be bent at their ends so as to prevent the dummy bar becoming wedged.
Claims (4)
1.- An electromagnetic stirrer in a continuous steel casting plant, in which the stirrer is installed at a distance from the casting path, one side of the stirrer facing the casting path, and wherein a dummy bar is introduced into a casting guide, characterised in that the side of the stirrer facing the casting path is provided with a guide device for the dummy bar, arranged at a distance from the casting path.
2.- An arrangement according to claim 1, charac-terised in that the guide device consists of at least one rail.
3.- An arrangement according to claim 1, charac-terised in that the guide device consists of a reinforced stirrer front plate.
4.- An arrangement according to claim 2 or 3, characterised in that the guide device has in the running direction of the inserted dummy bar end pieces directed towards the casting path.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH628679 | 1979-07-05 | ||
CH6286/79-8 | 1979-07-05 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1162600A true CA1162600A (en) | 1984-02-21 |
Family
ID=4307158
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000355376A Expired CA1162600A (en) | 1979-07-05 | 1980-07-03 | Electromagnetic stirrer in a continuous steel casting plant |
Country Status (6)
Country | Link |
---|---|
EP (1) | EP0022243B1 (en) |
JP (1) | JPS5611166A (en) |
AT (1) | ATE903T1 (en) |
CA (1) | CA1162600A (en) |
DE (1) | DE3060339D1 (en) |
ZA (1) | ZA804006B (en) |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5252895Y2 (en) * | 1973-04-18 | 1977-12-01 | ||
US3952791A (en) * | 1974-01-08 | 1976-04-27 | Nippon Steel Corporation | Method of continuous casting using linear magnetic field for core agitation |
-
1980
- 1980-07-02 DE DE8080103753T patent/DE3060339D1/en not_active Expired
- 1980-07-02 AT AT80103753T patent/ATE903T1/en not_active IP Right Cessation
- 1980-07-02 EP EP80103753A patent/EP0022243B1/en not_active Expired
- 1980-07-03 ZA ZA00804006A patent/ZA804006B/en unknown
- 1980-07-03 CA CA000355376A patent/CA1162600A/en not_active Expired
- 1980-07-04 JP JP9081380A patent/JPS5611166A/en active Pending
Also Published As
Publication number | Publication date |
---|---|
JPS5611166A (en) | 1981-02-04 |
ATE903T1 (en) | 1982-05-15 |
DE3060339D1 (en) | 1982-06-09 |
EP0022243A1 (en) | 1981-01-14 |
ZA804006B (en) | 1981-06-24 |
EP0022243B1 (en) | 1982-04-28 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
MKEX | Expiry |