WO1979000596A1 - Perfectionnements a la coulee de lingots metalliques - Google Patents

Perfectionnements a la coulee de lingots metalliques Download PDF

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Publication number
WO1979000596A1
WO1979000596A1 PCT/EP1979/000003 EP7900003W WO7900596A1 WO 1979000596 A1 WO1979000596 A1 WO 1979000596A1 EP 7900003 W EP7900003 W EP 7900003W WO 7900596 A1 WO7900596 A1 WO 7900596A1
Authority
WO
WIPO (PCT)
Prior art keywords
hot
wall
mold
ingot mold
ingot
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.)
Ceased
Application number
PCT/EP1979/000003
Other languages
English (en)
French (fr)
Inventor
E Vallak
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to BR7906448A priority Critical patent/BR7906448A/pt
Priority to DE792934887T priority patent/DE2934887T1/de
Publication of WO1979000596A1 publication Critical patent/WO1979000596A1/de
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D7/00—Casting ingots, e.g. from ferrous metals
    • B22D7/06—Ingot moulds or their manufacture
    • B22D7/10—Hot tops therefor
    • B22D7/102—Hot tops therefor from refractorial material only

Definitions

  • the present invention concerns casting metals in an ingot mold with the use of a so-called hot-top positioned on th.e mold to reduce pipe-formation in the solidified ingot.
  • the present invention consists in a method of casting metal ingots comprising teeming the molten metal in an ingot mold with a hot-top, the hot-top having a metal inner wall which is thin co pared to the thickness of the mold wall and which is surrounded by a heat insulating barrier, the resulting thermal expansion of the hot-top forming a gap between the inner wall of the hot-top and the shell of solidified metal on the ingot without external manipulation.
  • the invention in a second aspect consists in a hot-top for use with an ingot mold in the casting of metal ingots, the hot-top comprising a hollow body having a base adapted to be positioned at the upper end of an ingot mold and comprising an inner wall of heat conductive metal surrounded by a heat insulating barrier.
  • the invention consists in the combination of a hot-top as set forth inbefore with an ingot mold, where- in the thickness of the inner wall of the hot-top is chosen in relation to the capacity of the ingot mold in such a manner as to prevent melting or fusion of the inner wall during casting molten material in the mold, and wherein the inner wall is thin compared to the thickness of the mold wall.
  • the invention consists in an ingot mold comprising a hot-top, the hot-top having an inner wall which is thin compared to-the thickness of the mold wall and is made of heat conductive material having a higher melting point than the material of the mold wall, said inner wall being surrounded by a heat insulating barrier and being positioned inside the upper part of the ingot mold, the said heat insulating barrier being formed between said inner wall and the wall of the said upper part of the ingot mold.
  • Figure 1 is a cross section through an ingot mold and an associated hot-top according to a first embodiment of the invention
  • figure 2 is a cross section through an ingot mold with a hot-top according to another embodiment of the invention
  • figure 3 is a cross section through an ingot mold with incor- porated hot-top according to still another embodiment of the invention.
  • Figure 1 shows an ingot mold 1, a hot-top 2 and a cover plate 3 and is divided into two by a line A so that two stages of the casting process can be shown.
  • the left hand side of the figure shows the mold just after molten metal 4 has been poured into the mold.
  • the molten metal will normally be steel or iron, though non-ferrous metals may also be cast in a similar manner.
  • the hot-top 2 has a metal inner wall 5 having a thickness which is small compared to that of the mold walls.
  • the inner wall 5 is surrounded by a heat barrier 6 made from a (heat resistant) ceramic fiber material. It is essential that the thickness of the inner wall 5 be chosen in relation to the capacity of the mold 1 such that the wall will not melt or become fused with the poured molten metal.
  • the inner wall 5 should have a melting point which is not more than 300 C below the casting temperature of the molten metal.
  • the inner wall 5 may be 10 to 30 mm thick.
  • a suitable metal is cast iron but of course the material of the inner v / all will depend on the metal being cast. As shown in figure 1 the hot-top tapers from its base to its open top which is closed by the top cover 3. This taper is not, however, essential.
  • An additional heat barrier 9 is provided around the lower edge of the inner wall 5 to prevent heat transfer between the inner wall and the ingot mold. This additional heat barrier may not always be needed.
  • the hot-top is surrounded by a metal head case 10 provided with lifting lugs by means of which the hot-top and head case can be mounted on or removed from the ingot mold.
  • the metal may be poured either uphill or downhill.
  • the cover plate 3 which may be as described in U.K. patent specification No. 1,496,348, is placed on the hot-top after pouring.
  • FIG. 1 shows the molten metal immediately after teeming. Shortly after the poured metal contacts the inner wall 5 a thin outer layer or shell of solidified metal is formed on the poured metal due to heat being conducted away from the molten metal by the mold 1 and the inner wall 5 of the hot-top.
  • the metal is then allöwed to cool until it is solid. This is the situation shown in the right hand side of figure 1.
  • the hot-top 2 and the cover 3 re ain in position throughout the en- tire cooling process.
  • the gap 7, together with the insulation provided by the heat barrier 6, ensure that the upper portion of the ingot does not cool too rapidly with respect to the re-mainder of the ingot. Furthermore, there is no need to intro- cute exothermic material into the gap 7 during cooling of the cast metal because of the thermal insulation provided by the gap 7 and heat barrier 6.
  • the hot-top described is reusable and also avoids the necessity of Special Provision being made to move the hot-top mechanically during the casting Operation.
  • the hot-top may be advantageous to position means for causing extra thermal expansion of the hot-top when it is heated during teeming.
  • the sections of the hot-top may be separated by Strips of a material having a high degree of thermal expansion such as copper, or a bimetallic substance.
  • the inner surface of the hot-top may be coated with a heat reflective or a parting agent.
  • Figure 2 shows a hot-top positioned inside the upper part of an ingot mold 21.
  • An inner wall part 51 rests on a shoulder
  • the mold wall and is surrounded by a heat insulating barrier 61 corresponding to heat barrier 6 described above.
  • the outer wall of the hot-top is constituted by the wall of the ingot mold itself, which leads to a simplified structure of the co-combination.
  • a heat barrier " 91 can be inserted between the lower edge of wall 41 and the shoulder of the ingot mold.
  • the wall part 51 of the hot-top is made of a material such as steel hav ⁇ ing a higher melting point than the material of the input mold itself which is generally cast-iron.
  • Figure 3 shows an embodiment si ilar to that of figure 2 where ⁇ in an inner wall part 52 has a base part 53 which is incorporating in the wall of the ingot mold 22.
  • the inner wall of the hot-top is maintained at its lower edge in a given position with respect to the ingot mold, but its upper edge can expand to achieve the desired effect.
  • a heat barrier 62 is again inserted between the ingot mold wall and the inner wall part 52.
  • the embodiment of figure 3 provides an ingot mold in which the hot-top wall is incorporated at the time of making the ingot mold itself and does therefore not require an additional manufacturing step.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Molds, Cores, And Manufacturing Methods Thereof (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)

Description

Improvements in or relating to casting metal ingots
The present invention concerns casting metals in an ingot mould with the use of a so-called hot-top positioned on th.e mould to reduce pipe-formation in the solidified ingot.
Such a ethod is described in U.S. patent specification No. 3766965. In this U.S. patent specification olten metal is pou- red into an ingot mould having a hot-top. After a shell or lay- er of solidified metal has been formed the hot-top is moved me- chanically so as to provide a gap between the inner wall of the hot-top and the shell. This gap acts as insulation to prevent the upper portion of the ingot from cooling too rapidly.
Accordingly in one aspect the present invention consists in a method of casting metal ingots comprising teeming the molten metal in an ingot mould with a hot-top, the hot-top having a metal inner wall which is thin co pared to the thickness of the mould wall and which is surrounded by a heat insulating barrier, the resulting thermal expansion of the hot-top forming a gap between the inner wall of the hot-top and the shell of solidified metal on the ingot without external ma- nipulation.
In a second aspect the invention consists in a hot-top for use with an ingot mould in the casting of metal ingots, the hot-top comprising a hollow body having a base adapted to be positioned at the upper end of an ingot mould and comprising an inner wall of heat conductive metal surrounded by a heat insulating barrier.
OMPI . Ar 1P0 - In a third aspect the invention consists in the combination of a hot-top as set forth hereinbefore with an ingot mould, where- in the thickness of the inner wall of the hot-top is chosen in relation to the capacity of the ingot mould in such a manner as to prevent melting or fusion of the inner wall during casting molten material in the mould, and wherein the inner wall is thin compared to the thickness of the mould wall.
In a fourth aspect the invention consists in an ingot mould comprising a hot-top, the hot-top having an inner wall which is thin compared to-the thickness of the mould wall and is made of heat conductive material having a higher melting point than the material of the mould wall, said inner wall being surrounded by a heat insulating barrier and being positioned inside the upper part of the ingot mould, the said heat insulating barrier being formed between said inner wall and the wall of the said upper part of the ingot mould.
In order that the present invention may be more readily under- stood, various embodiments thereof will be described by way of example and with reference to the accompanying drawings wherein :
Figure 1 is a cross section through an ingot mould and an asso¬ ciated hot-top according to a first embodiment of the invention, figure 2 is a cross section through an ingot mould with a hot- top according to another embodiment of the invention, figure 3 is a cross section through an ingot mould with incor- porated hot-top according to still another embodiment of the invention.
Figure 1 shows an ingot mould 1, a hot-top 2 and a cover plate 3 and is divided into two by a line A so that two stages of the casting process can be shown. The left hand side of the figure shows the mould just after molten metal 4 has been poured into the mould. The molten metal will normally be steel or iron, though non-ferrous metals may also be cast in a similar manner.
OMPI A The hot-top 2 has a metal inner wall 5 having a thickness which is small compared to that of the mould walls. The inner wall 5 is surrounded by a heat barrier 6 made from a (heat resistant) ceramic fibre material. It is essential that the thickness of the inner wall 5 be chosen in relation to the capacity of the mould 1 such that the wall will not melt or become fused with the poured molten metal. The inner wall 5 should have a melting point which is not more than 300 C below the casting tempera- ture of the molten metal. The inner wall 5 may be 10 to 30 mm thick. A suitable metal is cast iron but of course the material of the inner v/all will depend on the metal being cast. As shown in figure 1 the hot-top tapers from its base to its open top which is closed by the top cover 3. This taper is not, however, essential.
An additional heat barrier 9 is provided around the lower edge of the inner wall 5 to prevent heat transfer between the inner wall and the ingot mould. This additional heat barrier may not always be needed.
The hot-top is surrounded by a metal head case 10 provided with lifting lugs by means of which the hot-top and head case can be mounted on or removed from the ingot mould.
The metal may be poured either uphill or downhill. In the lat¬ ter case the cover plate 3, which may be as described in U.K. patent specification No. 1,496,348, is placed on the hot-top after pouring.
As previously mentioned the left-hand side of figure 1 shows the molten metal immediately after teeming. Shortly after the poured metal contacts the inner wall 5 a thin outer layer or shell of solidified metal is formed on the poured metal due to heat being conducted away from the molten metal by the mould 1 and the inner wall 5 of the hot-top.
' The heat absorbed by the inner wall 5 causes the hot-top to expand. However, because of its lower mass with respect to the mould 1 the hot-top 2 will expand substantially more rapidly than the mould 1. Thus the hot-top is moved off the ingot with- out external manipulation to form a gap 7. Because of the above mentioned difference in masses the gap 7 between the hot-top 2 and the ingot will be formed more rapidly and will be larger than the gap between the ingot and the mould.
The metal is then allöwed to cool until it is solid. This is the Situation shown in the right hand side of figure 1. The hot-top 2 and the cover 3 re ain in position throughout the en- tire cooling process. The gap 7, together with the insulation provided by the heat barrier 6, ensure that the upper portion of the ingot does not cool too rapidly with respect to the re- mainder of the ingot. Furthermore, there is no need to intro- duce exothermic material into the gap 7 during cooling of the cast metal because of the thermal insulation provided by the gap 7 and heat barrier 6.
It will be appreciated that the hot-top described is reusable and also avoids the necessity of Special Provision being made to move the hot-top mechanically during the casting Operation.
Several modifications of the hot-top described above are possi- ble. Thus in the case where the metall inner wall of the hot- top is made from a number of sections, it may be advantageous to position means for causing extra thermal expansion of the hot-top when it is heated during teeming. Thus the sections of the hot-top may be separated by Strips of a material having a high degree of thermal expansion such as copper, or a bimetallic substance. Furthermore, the inner surface of the hot-top may be coated with a heat reflective or a parting agent.
Figure 2 shows a hot-top positioned inside the upper part of an ingot mould 21. An inner wall part 51 rests on a shoulder
'fΪJRE. the mould wall and is surrounded by a heat insulating barrier 61 corresponding to heat barrier 6 described above. The outer wall of the hot-top is constituted by the wall of the ingot mould itself, which leads to a simplified structure of the co - bination. A heat barrier" 91 can be inserted between the lower edge of wall 41 and the shoulder of the ingot mould. The wall part 51 of the hot-top is made of a material such as steel hav¬ ing a higher melting point than the material of the input mould itself which is generally cast-iron.
Figure 3 shows an embodiment si ilar to that of figure 2 where¬ in an inner wall part 52 has a base part 53 which is incorpora- ted in the wall of the ingot mould 22. In this case the inner wall of the hot-top is maintained at its lower edge in a given Position with respect to the ingot mould, but its upper edge can expand to achieve the desired effect. A heat barrier 62 is again inserted between the ingot mould wall and the inner wall part 52.
The embodiment of figure 3 provides an ingot mould in which the hot-top wall is incorporated at the time of making the ingot mould itself and does therefore not require an additional ma- nufacturing step.
It has been discovered that with the ingot mould and casting method described above the amount of piping on the final ingot is low and the contamination of the ingot is often negligible so that it can be rolled i mediately on being stripped from the mould.

Claims

1. A method of casting metal comprising teeming molten m into an ingot mould with a hot-top, the hot-top having a metal inner wall which is thin compared to the thickness of the mould wall and is surrounded by a heat insulating barrier, the resulting thermal expansion of the hot-top forming a gap between the inner wall of the hot-top and the shell of solidified metal on the ingot without exter¬ nal manipulation.
2. A method as claimed in claim 1, including inhibiting the transfer of heat between the inner wall and the ingot mould by an additional heat barrier.
3. A method as claimed in claim 1 or claim 2, wherein th or each heat barrier is made from ceramic fibre.
4. A method as claimed in any one of the preceding Clai wherein the inner wall is a metal having a melting point nnoott mmoorree tthhaann -300 C less than the melting point of the e tal being cast.
5. A method as claimed in any one of the preceding Claim including positioning a cover plate on the hot-top.
6. A method as claimed in claim 5, wherein the cover plate co prises ceramic fibre material.
7. A hot-top for use with an ingot mould in the casting of metal ingots, the hot-top co rpising a hollow body having a base adapted to be positioned at the upper end of an ingot mould, the body having an upper opening and being formed from an inner wall of heat conductive materi surrounded by a heat barrier of ceramic material.
8. A hot-top as claimed in claim 7, wherein the ceramic ma¬ terial is fibrous.
9. A hot-top as claimed in either claim 7 or claim 8, where¬ in the inner wall of the hot-top is coated with a parting of heat reflective material.
10. A hot-top as claimed in any one of Claims 7 to 9, where¬ in the inner wall is maded from a number of metal. plates in- terconnected by means for causing increased thermal expansion of the hot-top.
11. A hot-top as claimed in any one of claims 7 to 10, where¬ in the hot-top tapers from its base to its upper opening.
12. A hot-top as claimed in claim 10, wherein the means for causing increased thermal expansion comprise copper or bi¬ metallic material interposed between the plates.
13. A hot-top as claimed in any one of claims 7 to 12, where¬ in the lower edge of the inner wall is provided with an ad¬ ditional heat barrier to prevent heat transfer between the inner wall and the ingot mould.
14. A hot-top as claimed in any one of claims 7 to 13, and surrounded by a head case provided with lifting lugs.
15. A hot-top as claimed in any one of claims 7 to 14, where¬ in the inner wall is from 10 to 30 mm thick. •
16. The combination of a hot-top as claimed in ony one of claims 7 to 15 with an ingot mould, wherein the thicknes of the inner wall of the hot-top is chosen in relation t the capacity of the ingot mould in such a manner as to p vent melting or fusion of the inner wall during casting molten material in the mould, and wherein the inner wall thin compared to the thickness of the mould wall.
17. A combination as claimed in claim 16, and including cover plate for closing the open end of the hot-top, the cover plate including ceramic fibre material.
18. An ingot mould comprising a hot-top, the hot-top hav an inner wall which is thin compared to the thickness of mould wall and is made of heat conductive material havin higher melting point than the material of the mould wall said inner wall being surrounded by a heat insulating ba rier and being positioned inside the upper part of the i got mould.
19. An ingot mould as claimed in claim 18, wherein the l edge of the inner wall is provided with an additional he barrier to prevent heat transfer between the inner wall the ingot mould.
20. An ingot mould as claimed in claim 18, comprising me for holding the lower edge of the said inner wall in a g position with respect to the ingot mould.
21. An ingot mould as claimed in claim 18, wherein said ner wall is provided with a base part incorporated in t wall of the ingot mould.
PCT/EP1979/000003 1978-02-07 1979-01-25 Perfectionnements a la coulee de lingots metalliques Ceased WO1979000596A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
BR7906448A BR7906448A (pt) 1978-02-07 1979-01-25 Processo de lingotamento de metal,cabeca quente para uso com uma lingoteira no lingotamento de lingotes metalicos,combinacao de uma cabeca quente,e,lingoteira
DE792934887T DE2934887T1 (de) 1978-02-07 1979-01-25 Improvements in or relating to casting metal ingots

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB4957/78 1978-02-07
GB4957/78A GB1595737A (en) 1978-02-07 1978-02-07 Casting metal ingots

Publications (1)

Publication Number Publication Date
WO1979000596A1 true WO1979000596A1 (fr) 1979-08-23

Family

ID=9787080

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1979/000003 Ceased WO1979000596A1 (fr) 1978-02-07 1979-01-25 Perfectionnements a la coulee de lingots metalliques

Country Status (8)

Country Link
EP (1) EP0009028A1 (de)
JP (1) JPS55500084A (de)
BR (1) BR7906448A (de)
DE (1) DE2934887T1 (de)
FR (1) FR2448951A1 (de)
GB (1) GB1595737A (de)
SE (1) SE431833B (de)
WO (1) WO1979000596A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001377A1 (fr) * 1979-11-13 1981-05-28 Ferrox Co Ets Int Moule a lingot comprenant un haut a chaud positionne a l'interieur de la partie superieure du moule et procede de fabrication de ce moule
RU2841811C1 (ru) * 2025-02-24 2025-06-17 федеральное государственное бюджетное образовательное учреждение высшего образования "Нижегородский государственный технический университет им. Р.Е. Алексеева" (НГТУ) Прибыльная надставка

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4721278A (en) * 1986-10-14 1988-01-26 Re-Top Usa, Inc. Lightweight reusable hot top

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1696986A (en) * 1926-01-19 1929-01-01 Max R Trembour Hot top for molds
US1738600A (en) * 1928-10-31 1929-12-10 James Thomas Hot top
FR739258A (fr) * 1932-06-29 1933-01-09 Coquille de coulée pour métaux
FR2071442A5 (en) * 1969-12-30 1971-09-17 Daussan Henri Ingot casting mould partly exothermically - heated

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE587235C (de) * 1932-03-31 1933-11-01 Eugen Schwarz Verfahren zur Beheizung des verlorenen Kopfes oder der Steiger von Bloecken und Formstuecken
JPS50108B1 (de) * 1969-03-28 1975-01-06

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1696986A (en) * 1926-01-19 1929-01-01 Max R Trembour Hot top for molds
US1738600A (en) * 1928-10-31 1929-12-10 James Thomas Hot top
FR739258A (fr) * 1932-06-29 1933-01-09 Coquille de coulée pour métaux
FR2071442A5 (en) * 1969-12-30 1971-09-17 Daussan Henri Ingot casting mould partly exothermically - heated

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1981001377A1 (fr) * 1979-11-13 1981-05-28 Ferrox Co Ets Int Moule a lingot comprenant un haut a chaud positionne a l'interieur de la partie superieure du moule et procede de fabrication de ce moule
RU2841811C1 (ru) * 2025-02-24 2025-06-17 федеральное государственное бюджетное образовательное учреждение высшего образования "Нижегородский государственный технический университет им. Р.Е. Алексеева" (НГТУ) Прибыльная надставка

Also Published As

Publication number Publication date
GB1595737A (en) 1981-08-19
FR2448951A1 (fr) 1980-09-12
FR2448951B1 (de) 1983-10-28
SE431833B (sv) 1984-03-05
JPS55500084A (de) 1980-02-14
DE2934887C2 (de) 1988-07-14
DE2934887T1 (de) 1981-01-15
BR7906448A (pt) 1979-12-11
SE7908283L (sv) 1979-10-05
EP0009028A1 (de) 1980-03-19

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