US2210145A - Direct rolling of metal from the liquid state and apparatus therefor - Google Patents

Description

g- 6, 1940- J. H. L. DE BATS 2.210.145

DIRECT ROLLING 0F METAL FROM THE LIQUID STATE AND APPARATUS THEREFOR Filed Aug. 15, 1938 4 Sheets-Sheet l INVENTOR.

Jean H. L. De Bufs ATTORNEYS.

Aug. 6, 1940. J DE -rs 2.210.145.

DIRECT ROLLING 0F METAL FROM THE LIQUID STATE AND APPARATUS THEREFOR Filed Aug. is, 1938 4 Sheets-Sheet 2 INV ENTOR. Jean H. L. De 5075 ATTORNEYS.

Aug. 6, 1940.

J. H. L. DE BATS DIRECT ROLLING 0F METAL FROM THE LIQUID STATE AND APPARATUS THEREFOR 4 Sheets-Sheet 3 Filed Aug. 13, 1938 v we ' W a0 g4; Z44 L INVENTO R.

Jean hf L. De Bma ATTORNEYS.

g- 6, 1940. J. H. L. D: BATS 2.210.145

DIRECT ROLLING OF METAL FROM THE LIQUID STATE ANb APPARATUS THEREFOR Filed Aug.- 13, 1938 4 Sheets-Sheet 4 A iii-xx 3/4 lNVENTOR'.

I dean H. L. De Bats ATTORNEYS.

Patented Aug. 6, 1940 I UNITED STATES DIRECT ROLLING OF METAL FROM THE LIQUID STATE AND APPARATUS THERE- FOR Jean H. L. De Bats, East Orange, N. J., assignor to Metal Carbides Corporation, Youngstown, Ohio, a corporation of New Jersey Application August 13, 1938, Serial No. 224,658

11 Claims.

The novel features of the present invention 1 comprehend the direct formation of structural ly from the cast metal andwithout the intermediate formation of ingots or blooms. The invention also comprehends the continuous formation of metal shapes in novel forms of apparatus, and, in which the moltenmetal is initially frozen from one side of a to-be-formed shape, and thereafter is rolled andotherwise manipulated in a continuous and direct treatment to the finished shape. The several features of novelty include special apparatus and devices for use with the same, as well as special methods of procedure.

The above recited, and other desirable features and advantages of the present invention will be described in the specification and illustrated in the drawings, certain preferred forms of apparatus being shown, by way of example only, for, since *he underlying principles may be incorporated in other specific apparatus and devices, it is not intended to be limited to the ones here shown, except as such limitations are clearly imposed by the appended claims.

In the drawings, like numerals refer to similar parts throughout the several views, of which Fig. 1 is a broken top view of a continuous drawing apparatus;

Fig. 2 is a vertical longitudinal section of the apparatus of. Fig. 1;

Fig. 3 is a view similar to Fig. 1, showing an apparatus for making special shapes, and having a traveling furnace;

Fig. 4 is a longitudinal vertical section of the apparatus of Fig. 3;-

Fig. 5 is a-transverse vertical section taken on line 55 of-Fig. 4;

Fig, 6 is a plan view, partly in section; of an apparatus having a moving circular table;

Fig. '7 is a vertical section through the apparatus of Fig. 6, and

Figs. 8 and 9 are vie-.vs similar to Figs, 6 and 7, respectively, showing an apparatus having a traveling furnace and stationary casting plate. Considering the apparatus shown inv Figs. 1 and 2, it will be notedgthat a continuous belt or casting plate of heat conductive metal, such metal shapes of rolled metal proceedingdirectas copper or aluminum, is mounted for travel over a supporting plate or table and passes through a trough in the bottom of the apparatus, which trough is provided with a suitable coolant, such as water or brine. Mounted over the table is a furnace having an open bottom in contact with the moving belt or apron and hav ing an orifice or gate for defining and controllin the issuance and flow of metal at the edge forming the front of the device. The metal at the bottom of the furnace is chilled and frozen by its contact with the cooled belt or apron, and is carried forward through the gate as a newly formed strip of red hot metal. This strip of metal is chilled on one side only, due to the unilateral contact with the chilled forming surface. A leading strip or tongs carries the plastic metal strip through feed rolls to rolling apparatus, not shown, where the strip is worked down to size and proper crystalline structure. Due to the method of operation the rolled strip is formed and worked simultaneously with the development of crystal growth or formation in the mass. As the crystals are in statu nascendi they are worked before they have anyopportunity to grow, and the resulting structure is physically homogeneous, as to its crystalling structure, which condition is impossible of attainment in metal masses, such as ingots, where coarse and differential crystallization has taken place, and in which no amount of heat treating, soaking, and mechanical workings will compensate for or remove the in-crystallized differences. In addition, no porosity or pipe formation occurs in the products of the present invention, due to the withdrawal of a continuous layer of bottom, sound metal, from the furnace and theunilateral chilling of such metal.

The application of the initial chill from a single surface only, increases the structural efficiency of the products, and particularly of various steels and irons which may be used. This is believed to be due .to the fact that with a single chilled surface, there are not formed a number of freezing siirfaces, each tending to condense metal in itself at the expense of the center or core of the formed mass, as occurs in ingots cast according to present practices.

The apparatus, whose function has been described in-generai terms immediately above, and, as shown in Figs. 1 and 2, comprises a copper belt or apron of suitable thickness, of the order Spaced pedestals 24 support the side frames and 4 are secured thereto- A support or table 30 is mounted on and across the pedestals, and the belt 20 is adapted to pass thereover and be supported thereby. A coating of solid lubricant 3|, de-

sirably of graphite, is provided for the top of the table, and provides a frictionless bearing for the belt. The table 30 may be made of insulating arranged as to receive the lower or bottom segments of the rolls 2| and the belt 20, in its return travel, and-cool the several parts of the' apparatus which are exposed to the heat of the liquid metal. The amount and temperature of the coolant, and its rate of flow, will be carefully determined to assure the desired amount of heat withdrawal from the newly formed strip of hot metal 00. The furnace, or casting pot, 50, as shown, comprises an open-bottomed pot 5| of heat-resisting material, such as chromite,

brucite, and the like. The furnace is supported between framing members 23a of the structure. The front edge of the bottom of the crucible forms a throat or gate 52 for the issuing metal.

The remaining bottom edges 53 are in sliding contact with the moving belt 20, which forms a continuous, heat-removing traveling bottom for the assembly, as well as a carrying apron for the newly-formed metal strip 60. A regulating device 54 servesto determine and maintain the desired aperture opening of gate 52. A support 55 serves to' brace a crucible 56 during the pouring of molten metal 51 into the casting chamber 50. A sourceof controlled heat, such as high frequency coil 58, serves to maintain the metal 51 in a desired state of liquidity. It will be observed that the coil is spaced up from the belt 20. This is to prevent any induced electrical effects in the belt, and also to permit-the cooling of the bottom metal in contact with the moving belt, while, at the same time, maintaining the supply of metal in the upper part of the chamber sumciently liquid to prevent formation of pipe or any crystallization whatsoevern As noted above, the unilateral freezing and cooling afforded by the belt 20 insures that no structural physical or crystalline differences will be engendered in the newly solidified metal before it is subjected to the manipulative action of the working and forming rolls.

The continuous strip casting apparatus described immediately above, may be supplemented by other apparatus, in which the furnace travels, usually to-and-fro, in a fixed path over a stationary chill plate.

Referring more particularly to Figs. 3 and 4, the modified apparatus comprises a stationary, hollow base I00, having sides IM and a top or table portion I02. A coolant fluid I03 is introduced into member I through inlet I04 and is exhausted or withdrawn through outlet I05.

A separate heat-conductive plate H0 is mounted on and secured to the top I02 of the base. The plate III is provided with parallel edge grooves ill, adapted to receive flanges la,of the casting chamber 50 and by means of which the furnace is caused to maintain a desired to-and-fro travel over plate 0. Handles 53 may be secured to the casting chamber to permit its manual movement along and over the plate 0., This plate may be formed with casting channels of rectangular cross-section, as indicated by H2 in Figs. 3, 4 and 5, the front edge of the furnace being flush with the top of the casting channel or mold section, as distinguished from the detail of Figs. 1 and 2, in which the casting channel is formed in the front edge of the furnace. However, it may be the same as that of Figs. 1 and 2 if a flat table without the channel H2 is used.

These strips can be made at a minimum of cost and labor, but with a greatly improved physical condition, due to the fact that the initial unilateral chilling of the cast metal and the immediate working of the so-formed strip, permits the formation and securing of a uniform, fine crystalline structure, and in statu nascendi, without ever being exposed to conditions favoring the formation of coarsely crystalline particles in various parts of the metal bodies or masses and shapes produced.

Referring now to the structures delineated in Figs. 6 and '7, there is shown an apparatus comprising the usual furnace 50, and draw-off rolls 62, mounted on a framework 200. The framework includes a base.20l, sides 202, and a top, bridging member 203. The bridging member is provided with a plurality of aligned, vertical guiding rolls 204, in substantial alignment with one edge of the outlet or gate of the casting chamber. The casting chamber is held in place on member 203 and is in sliding contact with the upper'surface 22] of revolving table 220. ,The table is mounted for rotation on shaft 222 journaled in boss 204 onthe bottom of the framework 200. A second boss 205 is journaled to receive gear 206, which is in mesh with gear 201, the latter being secured to shaft 222 as a driving member therefor. A spiral gear 208, mounted on driving shaft 209, is in mesh with gear 205, and serves to furnish the necessary motive power for the rotation of table 220. Shaft 209 is 'journaled in the framing members 202, and is connected to a source of motive power, not shown. The casting table is made of copper, aluminum, or other heat-conductive material, and the surface may be coated with graphite. As the table is rotated, fresh chilling surfaces are constantly presented to the metal issuing from the casting chamber 50. The issuing strip 30 is guided along the aligning rolls 204, and is drawn through the take-off rolls 62 by the starting strip ii. The bulk of the metal in the casting table is such as to insure a chill effect on all molten metal contacted therewith. To prevent excess absorption or soaking up of heat in the table, the latter may be exposed to the action of coolant fluids, either liquid or gaseous.

The apparatus delineated in Figs. 8 and 9, comprises a stationary casting table, suitably cooled, and provided with an annular casting channel, together with a rotary arm carrying the furnace and adapted to discharge the liquid metal into the chill mold annulus, upon rotation of the arm. Considering the drawings more in detail, a table 333 is formed with a top surface 30!, a continuous cylindrical wall 302,-and a base 333, forming a liquid-tight joint with the wall 332. An inlet pipe 304 and an outlet pipe 335 provide means for the introduction and withdrawal of coolant fluid 336 from the, interior of the table. A casting channel 30], of annular shape and rectangular cross-section, is formed inthe table surface. The usual casting chamber 50 is mounted on an arm 3), which arm is rotatably carried and rotated by vertical shaft 3 journaled in the top and bottom members of the table 300. A ring gear 3I2 is secured to the shaft, and is driven by a spiral gear 3l3, mounted on shaft 3, which is journaled in the wall 302, and is driven by suitable driving mechanism, not shown. The outlet or gate'of the casting chamber will be in register with the casting channel. Trueannular shapes'may be formed in this apparatus, or the initially chilled strip 60d may be continuously removed as the furnace lays it down.

The several casting plates or members, as noted, are desirably made of metal, although, for some purposes, asbestos, and other mineral, heat-resisting materials may be used.-

It will now be appreciated that there have been shown and described a number of forms of casting apparatus suitable for the direct casting of liquid metals, such as steels and irons, into various forms and the immediate working of such materials, in a state of incipient crystallization, to prevent the formation of coarse crystalline structure and insure the formation of a uniform,'solidified condition in the mass.

What is claimed is:

1. The method of forming metal strip directly from liquid metal which comprises, depositing theliquid metal on a cooling surface and freezing the metal by cooling it only from the single surface which is in contact with the cooling surface, while inhibiting heat loss from other surfaces whereby to cause solidification from one surface only and to inhibit crystal growth from vessel and the cooling surface, and freezing the all other surfaces.

2. The method of forming metal strip directly from liquid metal which comprises, depositing the liquid metal on a cooling surface from a vessel which maintains a body of liquid metal while-causing relative movement between the metal by cooling it only from the single surface which is in contact with the cooling surface,

while inhibitingheat loss from other surfaces whereby to cause solidification from one surface only and to inhibit crystal growth from all other surfaces.

3. The method of forming metal strip directly from liquid metal which comprises, heating a body of metal in a furnace tokeep it molten, maintaining an extended bottom opening-of the furnace over a fiat cooling ,surface'with all sides of the opening touching the surface except an orifice on one side from which the strip of solidified metal issues, and causing relative movement between the furnace and the cooling surface to progressively deposit molten metal on the cooling surface at a rate to freeze it solely from the cooling surface to a thickness to substantially fill the orifice with solid metal as the strip issues therefrom, whereby to cause solidification from the bottomsurface only of the strip. and to inhibit solidification from all other surfaces. l

4. The method as setforth in claim 3 which further comprises in combination, filling; the orifice at the beginning of a pour with a starting member which holds the liquid metal in the furnace until freezingbegins and which moves out of the orifice as soon as the relative travel between the furnace'and cooling surface begins and the solidified strip begins to emerge from the orifice.

5. The method as set forth in claim 3 which further comprises in combination, filling the orifice with a starting strip having a furcated end, and moving the starting strip out of the orifice to draw the formed strip of solidified metal with it. I

6. The method of forming metal strip directly from liquid metal which comprises, holding the bottom edges of an open bottom melting furnace in engagement with a plane cooling surface, maintaining the body of metal in the furnace in molten condition but freezing the metal at the bottom of the furnace in a strip the width of the o 11 bottom, and drawing the strip out through n orifice on one side edge of the bottom the width of the bottom opening by causing relative surface movement between the furnace and cooling surface.

7. Apparatus for forming metal strip directly from liquid metal, comprising in combination, a metal melting furnace, a chill surface, said furnace having an extensive bottom opening above the three bottom side edges engaging said chill surface, said furnace also having a lateral orifice in the bottom edge of the fourth side the width of the bottom opening, and means for causing relative surface movement between said furnace and said chill surface.

8. Apparatus for forming metal strip directly from liquid metal, comprising in combination, a

gmetal melting furnace, a chill surface, said furnace having an extensive bottom opening above and three bottom edges engaging said chill surface, said furnace also having a lateral orifice in the bottom edge of the fourth side the width of the bottom opening, a starting strip.

adapted to fit in and fill said orifice, and means for causing relative surface movement between said furnace and said chill surface.

9. Apparatus for forming metal strip directly from molten metal, comprising in combination, a plane rotary cooling table, a molten metal container having a bottom opening-and the'edges thereof in engagement with the surface of said table, one side having an orifice in the bottom the'width of said bottom opening, means to rotate said table beneath said container, and stop guide means for one edge of the solidified strip as it leaves said table to prevent it from being carried around with the table.

10. The method of forming elongated metal bodies directly from liquid metal whichcomprises, depositing the'liquid metal on a cooling surface, facilitating cooling and solidification from one surface while simultaneously maintaining a body of. molten metal in contact with the opposite side and inhibiting cooling from that side until the elongated body has substantially solidified.

'11. The method of forming elongated metal bodies directly from liquid metal which comprises, depositing the liquid metal on a cooling surface progressively along its length, actively cooling and causing solidification from one surface while simultaneously, maintaining a'bath of molten metal in contactwith the opposite side, and actively heating the molten metal on that side until the elongated body has substantially solidified -where it separates from the bath.

JEAN H. L. DE BATS.

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