US3785609A

US3785609A - Device for the treatment of ferrous metal ingots which are intended to be removed from molds without hold-up periods

Info

Publication number: US3785609A
Application number: US00183767A
Authority: US
Inventors: G Daussan; A Daussan; J Daussan
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-10-07
Filing date: 1971-09-27
Publication date: 1974-01-15
Anticipated expiration: 1991-01-15
Also published as: FR2108808A1; AT319497B; ES395779A1; LU63894A1; FR2108808B1; NL7113685A; DE2147407A1; BE772674A; DE2147407B2; GB1344180A

Abstract

The device is constituted by a heat-insulating and/or exothermic lining, comprising a single element or a number of juxtaposed elements, provided with a metallic reinforcement which has an extensive open structure and forms meshes. One portion of the meshes is embedded in the thickness of the lining, whilst another portion, adjacent to the volume which is filled with molten metal, is uncovered. Since the contact surfaces between the mold and the metallic portions which serve to clamp the lining to the mold are quite small, the transmission of heat from the metal to the upper portion of the mold is greatly reduced with respect to known devices. Moreover the manufacture of each element only requires placing the corresponding portion of the reinforcement in a mold with permeable walls, wherein a slurry is fed; and the bonds between the lining, the reinforcement and the ingot are improved, which allows early displacement of the ingot after its removal from the mold.

Description

[ Jan. 15, 1974 10/1962 France................................ 249/201 78,287 5/1962 276,166 10/1964 Nether1ands..... ,309,266

[57] ABSTRACT DEVICE FOR THE TREATMENT OF FERROUS METAL INGOTS WHICH ARE INTENDED TO BE REMOVED FROM 1 MOLDS WITHOUT HOLD-UP PERIODS Primary ExaminerJ. Spencer Overholser [76] Inventors: Andre Daussan; Jean Charles Daussan; Gerard Daussan, all of 9, 2321 ggg gy i ffi :s Avenue Leclerc de l-lauteclocque, neyg p n Metz, France Sept. 27, 1971 [21] App]. No.: 183,767 The device is constituted by a heat-insulating and/or exothermic lining, comprising a single element or a Foreign Application priority Data number of juxtaposed elements, provided with a me- Oct 7 1970 France 7036202 tallic reinforcement which has an extensive open structure and forms meshes. One portion of the U S Cl 249/197 164M 249/199 meshes is embedded in the thickness of the lining, 111' Bzzd 7/10 whilst another portion, adjacent to the volume which Fieid is filled with molten metal, is uncovered. Since the 249 200 contact surfaces between the mold and the metallic portions which serve to clamp the lining to the mold References Cited are quite small, the transmission of heat from the metal to the upper portion of the mold is greatly re- UNITED STATES PATENTS duced with respect to known devices. Moreover the United States Patent Daussan et a1.

[22] Filed:

manufacture of each element only requires placing the corresponding portion of the reinforcement in a mold with permeable walls, wherein a slurry is fed; and the bonds between the lining, the reinforcement and the ingot are improved, which allows early displacement of the ingot after its removal from the mold.

3,106,756 Demaison.......... 3,165,797 LaBate............... 3,561,722 Kobusch et 211.... 3,512,572 Ednell................ 1,815,186 Co1es......,.......... 2,663,920

164/57 4 Claims, 33 Drawing Figures Anthony...........,.......

FOREIGN PATENTS OR APPLICATIONS 906,478 9/1962 Great Britain........................

PATENTEDJAH 1 5 1974 saw 01 or 10 PATENTEUJAN I 51174 SHEET 0%. 0F 10 Fig.7? 41 Fig.73

PATENTEUJAN 1 5 I974 SHEET us nr 10 Fig. 77

a ig Fig/.78

SHEET 01 or 10 PATENTEU JAN 1 51974 PATENTEUJAN 1 51914 3. 785 609 SHEET 08 0F 10 Fig.27 4

PATENTEBJAN 1 51374 sum as or 1o DEVICE FOR THE TREATMENT OF FERROUS METAL INGOTS WHICH ARE INTENDED TO BE REMOVED FROM MOLDS WITHOUT HOLD-UP PERIODS This invention relates to the pouring of ferrous metals into molds such as ingot-molds or raised top sections of ingot-molds and is more particularly directed to a device for the treatment of ferrous-metal ingots which are intended to be removed from molds without hold-up periods.

It is known to place over the internal surface of an ingot-mold either in the upper portion of this latter or within the interior of a raised top section a heatinsulating and/or exothermic lining which is intended to maintain liquid metal at the top portion of the bath during the solidification process for a sufficiently long period of time to ensure that the shrinkage cavities of the ingot are filled with the metal which has remained in the liquid state.

It is also known to complete the action of the abovementioned lateral lining by means of a heat-insulating and/or exothermic powder or so-called covering powder which is spread over the surface of the molten metal bath during filling of the ingot-mold or immediately afterwards.

The conventional hold-up period during which ingotmolds remain stationary after filling in order to demold ingots and displace these latter without danger varies respectively and broadly speaking between ninety minutes and five or six hours in the case of ingots of 5 to tons. This results in high costs not only in regard to immobilization of ingot-molds but also as a result of re tention in pit-type heating furnaces the foregoing indications are dependent on a number of factors and can be given only in order to give a clear idea.

Whatever precautions are taken in the pouring of ingots, the above-mentioned hold-up of ingot-molds cannot be substantially reduced without thereby impairing the quality of the ingot or like casting and without increasing the dangers involving personnel employed in operations of demolding and removal from the area which is used for filling ingot-molds.

In order to reduce the hold-up time, a known type of ingot-mold lining already exists (as disclosed in French Pat. No. 1,548,778) and is made up of heat-insulating plates which are reinforced on that face which is directed towards the ingot-mold wall. The reinforcement extends beyond the bottom edges of the plates and/or is fixed on the plates by means of metal studs which pass through said plates and project from the face which is directed towards the interior of the ingotmold. The molten metal which rises within the ingotmold is welded to those portions of the reinforcement which are not covered by the heat-insulating plates, said plates being thus attached to the ingot once this latter has solidified at its periphery. The ingot can then be removed from the mold and displaced without incurring the dangers mentioned above.

However, the use of a reinforced lining of this type results in a substantial heat loss through the reinforcement which is in contact with the ingot-mold wall over a large area. Furthermore, this type of lining is relatively complicated and costly to manufacture.

The present invention is intended to overcome these disadvantages while obtaining better behavior of the ingots or like castings during solidification in order to reduce losses of metal.

In accordance with the invention, the device for the treatment of ferrous-metal ingots which are intended to be demolded very shortly after filling of molds such as ingot-molds or raised top sections of ingot-molds is constituted by a heat-insulating and/or exothermic lining comprising a single element or a number of juxtaposed elements removably fixed prior to pouring and adjustable for height within the upper portion of the ingot-mold and in contact with the internal wall of said mold, said lining being provided with a metallic reinforcement which is welded to the molten metal when said metal is poured into the mold so that the lining is thus maintained in contact with the ingot until said ingot is introduced into the rolling mill. The device is distinguished by the fact that the metallic reinforcement has an extensive open structure and forms meshes of which one portion is embedded in the thickness of the lining whilst anothe portion is uncovered, the uncovered portion being adjacent to the volume which is filled with molten metal during the pouring operation.

By means of this device, the transmission of heat from the molten metal of the metal which is in process of solidification to the upper portion of the mold is much lower than in the case of devices which have been known up to the present time since the contact surfaces between the mold and the metallic portions which serve to clamp the lining are very small or even wholly absent.

Moreover, the manufacture of each element of the lining is simple and economical since it is only necessary to place the corresponding portion of the reinforcement in a mold having permeable walls and a slurry containing in suspension the heat-insulating and- /or exothermic substance which is intended to constitute the lining is fed into the interior of said mold.

Finally, the bond which is formed on the one hand between the reinforcement and the heat-insulating and- /or exothermic substance of the lining and on the other hand between said reinforcement and the ingot during solidification is very appreciably enhanced by virtue of the fact that the reinforcement is provided with open portions and forms meshes it is therefore possible to displace the ingot immediately after removal from the mold and with the minimum danger.

By virtue of the invention, the yield of the metallurgical operation considered has been successfully increased from 86 to 92 this yield represents the weight of the sound ingot which is freed from the top crop-end, from the bottom crop-end and from surface oxidations as related to the weight of the as-cast ingot. Since the second and the third causes of losses remain the same, the resulting improvement in the yield which is solely due to a reduction in the top crop-end can attain approximately 6 this improvement is considerable since the smallest top crop-end which was obtained in the prior art was ll The lining in accordance with the invention is preferably provided with recesses which uncover part of the meshes of the reinforcement and communicate with the molten metal through at least one lateral opening at the latest when said metal reaches its highest level within the mold.

In an advantageous embodiment of the invention, provision is made for the addition of a device for distributing covering powder the device which is employed as a lining automatically forms a cover which has a central opening and is intended to facilitate demolding of the ingot and transportation of this latter to the pit-type furnace or to any other location in order to ensure that the area such as the casting pit at which the filling of ingot-molds takes place is cleared in a very short period of time.

Further advantages and characteristic features of the invention will become apparent from the following description.

Different embodiments of the invention are illustrated in the accompanying drawings which are given solely by way of non-limitative example, and in which FIG. 1 is a vertical half-sectional view taken along line I-I of FIG. 3, in which the device and the top portion of the ingot-mold are shown prior to pouring in a first embodiment of the invention FIG. 2 is a vertical half-sectional view taken along line II-II of FIG. 3, in which the device and the top portion of the ingot-mold are shown at the end of filling with molten metal FIG. 3 is a corresponding horizontal sectional view taken along line III-III of FIG. I and prior to pouring FIG. 4 is a plan view in actual size and showing a fragment of metallic reinforcement of a particular type FIG. 5 is a vertical sectional view taken along line VV of FIG. 6 and showing a second embodiment of the invention FIG. 6 is the corresponding horizontal sectional view taken along line VIVI of FIG. 5

FIG. 7 represents a half-elevation of one of the elements which constitutes the device in a third embodiment of the invention FIG. 8 is a vertical sectional view taken along line VIIIVIII of FIG. 7

FIG. 9 is a half-view in plan corresponding to FIG. 7

FIG. 10 is a diagrammatic cutaway view in perspective showing one of the elements constituting the device in an alternative form of the third embodiment of the invention FIG. 11 is a half-view in elevation showing one of the elements constituting the device in a fourth embodiment of the invention FIG. 12 is a vertical sectional view taken along line XIIXII of FIG. 11

FIG. 13 is a horizontal half-sectional view taken along line XIIIXIII of FIG. 11

FIG. 14 is a perspective view of the element which is illustrated in FIGS. 11, 12 and 13, this view being taken on the side opposite to that which is visible in FIG. 11

FIG. 15 is a view which is similar to FIG. 14 but relates to an alternative form of the fourth embodiment of the invention FIG. 16 is a view in elevation showing one of the elements constituting the device in a fifth embodiment of the invention FIG. 17 is a vertical sectional view taken along line XVII-XVII of FIG. 16

FIG. 18 is a horizontal sectional view taken along line XVIII-XVIII of FIG. 16

FIG. 19 is a perspective view of an element which forms part of an alternative form of the fifth embodiment of the invention FIG. 20 is a vertical sectional view taken along line XX-XX of FIG. 21 and showing the top portion of an ingot-mold fitted with a device corresponding to a sixth embodiment of the invention FIG. 21 is a horizontal sectional view taken along line XXL-XXI of FIG. 20

FIG. 22 is a horizontal sectional view taken along line XXIL-XXII of FIG. 23

FIG. 23 is a view in elevation showing two consecutive elements of the device illustrated in FIGS. 20 and 21, said elements being opened-out along a common vertical plane FIG. 24 is a view in elevation showing one of the two clamping wedges forming part of the device which is illustrated in FIGS. 20 and 21 FIG. 25 is a vertical sectional view taken along line XXVXXV of FIG. 26 and showing the top portion of an ingot-mold which is fitted with a device corresponding to a seventh embodiment of the invention FIG. 26 is a plan view corresponding to FIG. 25

FIG. 27 is a vertical sectional view taken along line XXVII-XXVII of FIG. 28 and showing the top portion of an ingot-mold which is fitted with a device corresponding to an eighth embodiment of the invention after filling with molten metal and incipient solidification of this latter FIG. 28 is a plan view corresponding to FIG. 27, assuming that the hopper which is placed above the device has been removed FIG. 29 is a vertical half-sectional view taken along the chain-dotted line XXIXXXIX of FIG. 31 and showing the top portion of an ingot-mold fitted with a device corresponding to a ninth embodiment of the invention prior to pouring of the metal FIG. 30 is a vertical half-sectional view taken along the chain-dotted line XXXXXX of FIG. 31 and showing the top portion of an ingot-mold fitted with a device corresoponding to a ninth embodiment of the invention after filling with metal and incipient solidification of this latter FIG. 31 is a plan view corresponding to FIGS. 29 and 30 FIG. 32 is a fragmentary perspective view showing one of the elements constituting the device in accordance with the second embodiment of the invention and looking on that side which is in contact with the mold FIG. 33 is a view which is similar to FIG. 32 but relates to an alternative form of the second embodiment of the invention.

There is shown in FIGS. 1 to 3 the top portion of an ingot-mold 1 within which is placed a lining 11 formed in known manner by four plates 12 and four clamping wedges 13 the horizontal cross-section of these latter progressively decreases in the downward direction but the reverse arrangement could also be adopted, in which case the clamping action is produced by the plates instead of the wedges.

In accordance with the invention, a metallic reinforcement 14 is embedded in each of the plates 12 and in each of the wedges 13. One example of construction of said metallic reinforcement 14 is given in FIG. 4 which shows a wire-netting reinforcement in actual size. However, many other designs are possible without departing from the scope of the invention. A first set of designs comprises substantially linear metallic elements in intercrossed relation which may or may not be joined together these elements can be wires but also suitably oriented metal rods or expanded" metal. A second set of designs of the reinforcement comprises perforated metal sheets and these latter can in particular be either flat, corrugated or even provided with pleats.

There would still be no departure from the scope of the invention if provision were made for metallic reinforcements only within the plates 12 but not in the wedges 13 or if the metallic reinforcement 14 of one plate 12 were made up of a number of sections separated from each other.

That portion of the lining 11 which is located between the metallic reinforcement 14 and the internal wall of the ingot-mold 1 is provided with recesses consisting of substantially vertical channels 15 which open at the top into the atmosphere and are closed at the lower ends. Further recesses are constituted by lateral openings 16 each providing a communication between the base of each channel 15 and the internal face of the lining 11 which is in contact with the molten metal 2 during the pouring operation.

When the level of the molten metal rises within the ingot-mold 1, said metal comes into contact with the metallic reinforcement 14 through the lateral openings 16, then fills the channels 15 along which said molten metal is also in contact with the metallic reinforcement 14 as shown in FIG. 2. When the poured metal solidifies, said metal is welded to the metallic reinforcement 14 at the bottom of the lateral openings 16 and the channels 15. Once the solidification is sufficiently far advanced, the lining 11 is surrounded by thin metal lugs formed within the channels 15 said lugs are welded to the metallic reinforcement which is in turn welded to the mass of the ingot by the metal which fills the lateral openings 16. If the reinforcement has sufficient strength, the lining cannot be separated from the ingot when this latter is removed from the mold and then transported into the pittype heating furnaces this separation takes place only at the moment rolling when the ingot is flattened by the rolls of the rolling-mill.

In this embodiment, the air which is forced back by the molten metal as this latter penetrates into the lateral openings 16 and into the channels 15 as well as the gases which are given off by the molten metal are discharged to the surrounding atmosphere through the open upper extremities of the channels 15.

For the correct performance of operations, it is naturally essential to ensure that the metal forming the reinforcement 14 is welded to the metal 2 which is poured into the ingot-mold when these two metals are in contact with the lower ends of the recesses formed in the lining 11 it is also essential to ensure that the metal of the reinforcement 14 retains appreciable mechanical strength at the temperatures to which said reinforcementis heated between pouring and rolling.

Said reinforcement can advantageously be formed by means of a grid having hexagonal meshes as standardized in Germany under the designation Drahtgitter No. 9 D-l DIN l7l40 and the analysis of which complies with the following conditions carbon less than 0.10

manganese less than 0.50

phosphorus less than 0.09

sulphur less than 0.08

In a second embodiment of the invention which is illustrated in FIGS. 5, 6 and 32, the metallic reinforcement 24 of each of the plates 22 which form the lining 21 when assembled together is provided with a series of vertical pleats this series defines alternately salient and re-entrant vertical bands so that the cross-section of the reinforcement along a horizontal plane forms a so-called box-pleat pattern. The salient vertical bands 28 of the reinforcement 24 are located on the external surface of the lining 21 which is in contact with the ingot-mold 1 at the moment of positioning for pouring. The reentrant bands 29 are embedded in the plates 22, with the result that the metallic reinforcement 24 is firmly anchored in the lining 21.

In this second embodiment, the lining 21 is provided as in the first embodiment with recesses consisting of vertical channels 25 and lateral openings 26. The vertical channels 25 are again formed in that face of the lining 21 which is in contact with the ingot-mold 1 however, instead of being located outside the reinforcement with respect to the poured metal, said channels are separated from the ingot-mold l by the salient vertical bands 28 furthermore, said channels are usually open at both ends, namely to the surrounding atmosphere at the top and to the poured metal at the bottom. The lateral openings 26 extend directly to the bottom of the vertical channels 25 without interposition of any portion of reinforcemennt.

During the pouring operation, the result achieved is exactly the same as in the case of the device according to the first embodiment of the invention except for the fact that the molten metal first penetrates into the channels 25 at the lower ends thereof before passing through the lateral openings 26 after solidification of the poured metal, the metal lugs are directly welded to the ingot at the lower ends thereof.

In a first alternative form of this second embodiment of the invention which is illustrated in the central portion of FIG; 5 and in the right-hand portion of FIG. 32, the vertical channels 27 do not communicate with the atmosphere through the upper ends thereof but each channel stops at the level of the lateral opening 26 and is in communication with this latter. The lower end of the correspoding metal lug is welded to the ingot but this lug is not formed up to the full height of the lining 21 it can nevertheless attain three-quarters of this height or even slightly more.

In a second alternative embodiment, the lining is not provided with a lateral opening and the vertical channels 27 shown in FIG. 33 terminate in a blind end at the top. In this case, the molten metal which rises within the channels compresses the air which is imprisoned therein and stops before having reached the ends of the channels; it is further observed in some instances that the metal remains in the liquid state over a longer period of time within the channels, thereby endowing the metal lugs with higher strength.

A number of different alternative designs may clearly be combined within the same lining as is the case with the lining shown in FIG. 5.

It can also be noted from FIGS. 5 and 6 that the lining 21 which is illustrated is constituted solely by four plates 22 having juxtaposed edges which are inclined to the faces at an angle of 45 however, it is readily understood that this lining could also be provided with clamping wedges similar to those shown in FIGS. 1, 2 and 3.

According to a third embodiment of the invention which is illustrated in FIGS. 7, 8 and 9, the recesses formed in the plates 32 which constitute the lining 31 are provided with lateral openings 36 similar to those of the two first embodiments and with vertical passages 35 which are wholly formed within the interior of each plate 32. The lateral openings 36 extend into the vertical passages 35 which communicate with the atmosphere at the upper ends thereof but stop at the lower ends at the level of those lateral openings 36 which are located nearest the bottom of the plate 32.

The metallic reinforcement 34 is placed within the plate 32 in such a manner as to ensure that the vertical passages 35 are adjacent thereto and that said reinforcement is located on the side remote from the lateral openings 36 with respect to said passages.

In this case, the metal lugs which are formed within the vertical passages 35 during solidification are isolated from the ingot-mold by part of the thickness of the lining 31, thereby reducing heat losses.

In accordance with an alternative form of this third embodiment of the invention as illustrated in FIG. 10, the metallic reinforcement 34 is located on the same side as the lateral openings 36 with respect to the vertical passages 37. In consequence, the metal lugs which are formed as a result of solidification of the metal are located externally of the reinforcement with respect to the ingot.

In a fourth embodiment of the invention which is illustrated in FIGS. 11, l2, l3 and 14, the recesses formed in each plate 42 which constitutes the lining 41 are provided with lateral openings 46 which are similar to those of the three first embodiments and with vertical channels 45 formed in that face of the plate 42 which is in contact with the ingot-mold at the moment of pouring. However, said vertical channels 45 have a horizontal cross-section which is insufficient to permit the molten metal to pass into the channels by reason of its high viscosity in addition, the channels do not communicate directly with the lateral openings 46 but by means of horizontal ducts 48 of small cross-sectional area.

The metallic reinforcement 44 is completely embedded in the plate 42 except at the bottom of each lateral opening 46, at which the reinforcement is uncovered over an area which is equal to the vertical cross-section of said opening.

During the pouring operation, the molten metal fills the lateral openings 46 and is welded to the metallic reinforcement 44 at the bottom of said openings. The horizontal ducts 48 and the vertical channels 45 permit the discharge of air and of the gases which are given off by the molten metal. After solidification, the lining 41 is retained against the ingot only by the metallic reinforcement 44 which is in turn attached to the ingot by means of a small number of welds.

In an alternative form of this fourth embodiment of the invention as shown in FIG. 15, the lining is provided instead of the vertical channels 45 with vertical ducts 47 having a small cross-sectional area and entirely formed within each plate 42, the upper ends of said ducts being intended to communicate with the atmosphere and the lower ends being intended to communicate with the horizontal ducts 48 of small crosssectional area.

In a fifth embodiment of the invention which is illustrated in FIGS. l6, l7 and 18, each plate 52 in the assembly of plates which constitutes the lining 51 is provided at one end with an extension forming a return 53 so that the horizontal cross-section of the plate has the shape of a right-angle in addition, the end faces of each plate 52 are inclined to the vertical, the complete lining 51 being consequently jammed in position when assembled in the ingot-mold l.

The recesses of the lining consist solely of lateral openings 56 formed in that face of the lining which is in contact with the molten metal at the moment of pouring. These lateral openings 56 have a flared shape, the largest cross-section being located at the end nearest the molten metal bath said shape can be that of a frustum either of a pyramid or of a cone having a horizontal axis.

The metallic reinforcement 54 is completely embedded in the plate 52 except at the bottom of each flared lateral opening 56 where said reinforcement is uncovered over an area equal to the smallest vertical crosssection of said opening. The reinforcement consists of a series of vertical pleats forming a box-pleat pattern in horizontal cross-section and is therefore made up of salient bands 58 and re-entrant bands 59, the flared openings 56 being adjacent to the bands last mentioned. This arrangement of the metallic reinforcement 54 results in a greater thickness of the plates 52 and endows the lining 51 with added strength. Finally, the metallic reinforcement 54 is provided with a right-angled return 55 in the same manner as the plate 52 in which said reinforcement is embedded.

At the time of pouring and when the molten metal penetrates into one of the flared lateral openings 56, the air and the gases which are given off by the metal are discharged along the upper portion of said opening by virtue of the fact that this latter is inclined to the horizontal. The molten metal can thus be welded to the metallic reinforcement 54 at the bottom of each flared lateral opening and no other recess is necessary.

In an alternative form of this fifth embodiment of the invention as shown in FIG. 19, the metallic reinforcement 54 is flat but is provided with a right-angled extension 55 as in FIG. 18.

In a sixth embodiment of the invention which is illustrated in FIGS. 20, 21, 22, 23, 24, the lining 61 is an articulated lining constituted by four plates 62 and by two wedges 63, the plates 62 being such as to form two pairs which are separated from each other by the wedges 63. Each plate 62 and each wedge 63 is provided on that face which is in contact with the molten metal at the moment of pouring with flared lateral openings 66 which are similar to the openings 56 described earlier. Each pair of plates has a flat metallic reinforcement 64 which is common to the two plates said plates are thus secured to each other while being capable of pivotal movement with respect to each other about a hinge 65 constituted by the vertical section of the metallic reinforcement 64 which is located at the end of the two plates.

It is apparent from FIGS. 21 and 22 that the metallic reinforcement 64 is completely embedded in the pair of plates 62 with which the reinforcement is associated except at the bottom of each flared lateral opening 66 and along the hinge 65. However, the use of articulated plates which is a distinctive feature of the sixth embodiment of the invention is not limited in any sense to the mode of connection between the metallic reinforcement of the lining and the poured metal which is shown in FIGS. 20 and 21. Similarly, the use of wedges 63 does not constitute an essential requirement of this embodiment.

Moreover, the metallic reinforcement could be common to more than two plates and serve, for example, as a connecting element between all the plates of a single lining of the type shown in FIG. 6.

In a seventh embodiment of the invention which is illustrated in FIGS. and 26, the lining 71 is made up of four plates 72 having juxtaposed edges which are inclined to the faces at an angle of 45 and are not provided with any recess. The metallic reinforcement 74 of each plate 72 has a series of horizontal pleats located substantially at right angles and forming a box-pleat pattern in vertical cross-section the reinforcement is therefore made up of salient bands 78 and re-entrant bands 79. The salient bands 78 are applied against that face of the plate 72 which is in contact with the molten metal during the pouring operation whereas the reentrant bands 79 are embedded in the plate. When the molten metal fills the ingot-mold, it is welded to the salient bands 78 and the lining is thus retained against the ingot until this latter is subjected to a rolling operation.

This particularly simple mode of connection between the lining and the ingot can also be carried out with vertical bands which are alternately salient and reentrant or even with bands which are oriented in any manner with respect to the axis of the ingot-mold. It would also be possible to make use of metallic reinforcement with salient portions which are welded to the molten metal and re-entrant portions which are embedded in the lining but the salient and re-entrant portions need not necessarily have a configuration of bands arranged uniformly in alternate succession.

In an eighth embodiment of the invention which is illustrated in FIGS. 27 and 28, the lining 81 is made up of four plates 82, the top portions of which are bentback towards the interior of the mold l. The assembly consisting of inwardly bent portions 83 of the plates 82 forms a virtual cover for the molten metal bath and this cover is provided with'a central opening 89. The metallic reinforcement 84 of each plate 82 is provided at the top with an inwardly bent portion 87 which closely corresponds in shape to the corresponding portion 83 of the plate.

The lower portion of the lining 81 which is in contact with the wall of the ingot-mold 1 has the arrangement which is described above in connection with the fourth embodiment of the invention and illustrated in FIGS. 11 to 14. Thus, each plate 82 is provided with lateral openings 86 at the bottom of which the molten metal is welded to the metallic reinforcement 84 and with vertical channels 85 having a small cross-sectional area for the discharge of air and gases, the lateral openings 86 being intended to communicate with the vertical channels 85 by means of narrow ducts 88. However, arrangements which are different from this latter and arise from other embodiments of the invention as described in the foregoing could also be adopted for the lower portion of the lining 81.

The inwardly bent portion 83 of each plate 82 has bottom openings 91 which are similar to the lateral openings 86 and at the bottom of which the molten metal is welded to the inwardly bent portion 87 of the metallic reinforcement vertical ducts 92 of small cross-sectional area provide a communication between the ends of the bottom openings 91 and the surrounding atmosphere for the purpose of discharging air and gases.

A hopper 4 is placed above the central opening 89 of the lining 81 and is applied against the top edges of the inwardly bent portions 83. The hopper can be filled with an insulating and/or exothermic covering powder 5 in order to supply the shrinkage cavity 3 of the mo]- ten metal bath which is formed during solidification of the molten metal 2. At the end of the shrinkage process, a solidified metal film continues to adhere to the underface of the inwardly-bent portions 83 of the lining 81 and the strength of this latter is thus increased.

In FIG. 28, it is assumed that the hopper 4 has been removed.

In an alternative form of this eighth embodiment of the invention as shown in FIGS. 29, 30 and 31, the inwardly-bent portion 83 of each plate 82 has inclined passages 93 which open at the top ends in the edge of the central opening 89 and which are provided with downward extensions in the form of vertical ducts 94 in that portion of the lining which is in contact with the ingot-mold. The said ducts communicate with openings 96 formed in those faces of the plates 82 which are in contact with the-molten metal and may extend to the base of the lining 81 if necessary. Vertical ducts 92 and vertical channels which are both of small crosssectional area establish a communication between the inclined passages 93 and the lower portion of the vertical ducts 94 respectively and the surrounding atmosphere.

The metallic reinforcement 84 and the inwardly bent portion 87 which forms an upward extension of said reinforcement are adjacent respectively to the vertical passages 94 and inclined passages 93. Yaid passages are filled during the pouring operation with molten metal which can penetrate therein either through the lower ends which communicate with the openings 96 or through the upper ends which'open in the edge of the central opening 89 the air and the gases are discharged to the atmosphere through vertical ducts 92 and through the vertical channels 85. The metal which has filled the passages is welded to the metallic reinforcement 84 and to the inwardly bent portion 87, thus ensuring a very effective connection between the ingot and the lining and at the same time increasing the cohesion between that portion of each plate 82 which is in contact with the internal wall of the mold l and the inwardly bent portion 83 which forms part of the cover.

In FIG. 29, there are shown the openings 96 having a flared shape as described in the fifth embodiment of the invention and the openings of the bottom row which do not communicate with the vertical channels 85. It is apparent that many combinations can be obtained between the form of lining comprising a cover which is illustrated in FIGS. 27 to 31 and the different modes of connection between the metallic reinforcement and the lining which are illustrated in the preceding figures.

In all the embodiments of the invention which have been described in the foregoing, the lining can be constituted by an insulating and/or exothermic material, the following analyses of which are given only by way of example and without any limitation.

Insulating material Formula I fl 5 nq oneness index: 70) to Mineral or organic binder 5 to 10 Formula II Fibrous refractory materials such as asbestos or rock wool l to 35 Fibrous organic materials such as sawdust or paper pulp l to 20 7n Refractory or semi-refractory mineral materials such as silica. magnesia or diatomaceous earth 45 to /1 Natural or synthetic. mineral or organic binder l to l5 Exothermic material Oxidants 20 to 5 Aluminum 8 to 30 71 Fibrous refractory materials (asbestos or rock wool, for example) 1 to 35 Fibrous organic materials (paper pulp sawdust, etc) 1 to 20 71 More or less refractory mineral materials such as silica, magnesia, diatomaceous earth, etc. 45 to 90 7: Binder (mineral or organic, natural or synthetic starchy materials. phenolic resin,

sodium silicate) l to 7c The insulating and/0r exothermic covering powder 5 which was mentioned in connection with the eighth embodiment can correspond to one of the following analyses which are also given by way of non-limitative example.

Insulating covering powder Alumina 30 to 40 7c Silica 40 to 30 Carbon 10 to Fluxes such as sodium carbonate l0 to 5 "/1. Fluorspar l0 to 5 '7:

Exothermic covering powder Silica or alumina 44 to 67 Carbon 20 to 5 Fluorspar l to 5 74 Aluminum to 8 Oxidants 5 to 15 71.

Generally speaking, the invention is obviously not limited to the embodiments which have been described and many alternative forms other than those which were mentioned in the foregoing description can accordingly be contemplated. In particular, the lining could be designed in a single-unit form such as a pot or cup without departing from the scope of the invention.

The metallic reinforcement can extend to the full height of the lining as is illustrated in particular in FIG. 5 or only to a part of this height as is shown in the majority of the figures. The height of the metallic reinforcement is preferably within the range of 30 to of the height of the lining. When the metallic reinforcement only extends to a part of the height of the lining, the top edge of the reinforcement is preferably located in the vicinity of the top edge of the lining since it is the top portion of this latter which can most usefully be reinforced and securely attached to the ingot.

We claim:

1. A lining for retarding cooling of ferrous-metal ingots which are intended to be demolded very shortly after filling of molds such as ingot-molds or raised top sections of ingot-molds, said lining being removably fixed prior to pouring and adjustable for height within the upper portion of the ingot-mold and in contact with the internal wall of said mold, the body of said lining having its outer surface shaped to contact the inner wall ofa mold about the upper portion of the mold and having embedded therein a metallic reinforcement which is to be founded to the molten metal when said metal is poured into the mold wherein the said metallic reinforcement has an extensive open structure and forms meshes, and wherein the lining has a plurality of spaced, inwardly opening recesses which extend from the inner surface of the lining to a depth sufficient to uncover a part of the meshes of the reinforcement only at spaced points on the reinforcement without creating a complete discontinuity in the body of the lining material.

2. A lining as claimed in claim 1, said recesses having a flared shape the largest cross section of which is located on the internal face of the lining with which the molten metal comes into contact during the pouring operation.

3. A lining as claimed in claim 1, said lining spacing and insulating said metal reinforcement from said internal wall of said mold.

4. A lining as claimed in claim 3, said reinforcement being entirely out of contact with said internal wall of said mold.

Claims

1. A lining for retarding cooling of ferrous-metal ingots which are intended to be demolded very shortly after filling of molds such as ingot-molds or raised top sections of ingot-molds, said lining being removably fixed prior to pouring and adjustable for height within the upper portion of the ingot-mold and in contact with the internal wall of said mold, the body of said lining having its outer surface shaped to contact the inner wall of a mold about the upper portion of the mold and having embedded therein a metallic reinforcement which is to be bounded to the molten metal when said metal is poured into the mold wherein the said metallic reinforcement has an extensive open structure and forms meshes, and wherein the lining has a plurality of spaced, inwardly opening recesses which extend from the inner surface of the lining to a depth sufficient to uncover a part of the meshes of the reinforcement only at spaced points on the reinforcement without creating a complete discontinuity in the body of the lining material.