US1535248A - Method of casting ingots - Google Patents

Description

Apfil 2s, 1925.

1,535,248 J. E. PERRY METHOD OI CASTING INGOTS Filed Feb. 10, 1923 April 28, 1925. 5 Y 1,535,248

J. E. PERRY METHOD 0F CASTING INGoTs Filed Feb. 10, 1925 2 Sheets-Sheet 2 wuefntoz .fa/272 E. Perry Patented pr. 28, 1925o UNITED vSTATES PATENT OFFICE;

i JOHN EDMUND PERRY, OF SHARON,` PENNSYLVANIA, ASSIGNOR'TO VALLEYMOULD & IRON CORPORATION, OF SHARPSVILLE, PENNSYLVANIA, A. CORPORATION O NEW YORK.

METHOD OF CASTING INGOTS.

Application led February 10, 1923. Serial No. 618,206.

To all wlw/m, it may concern: i

Be it known that I, JOHN E. PERRY, a citizen of the United States, residing at Sharon, 1n the county of Mercer, in the State 5 of Pennsylvania, have invented certa-in new and useful Improvements inv Methods of Casting Ingots, of which the :following is a specification.

I-Ieretofore in the artl of casting steel ingots it has been customary to cast the ingots in vertical molds having substantially a rectangular crosssection which were adapted to be filled with the steel in contact with the four walls during the filling operation. Such molds have been both top and bottom poured and the control of the freezing action has been such that the steel solidified from the four sides of the molds inwardly until the center of the steel is sufficiently reduced in temperature to crystallize. Under this old practice there has been more or less definite lines of crystallization established within the ingot, one zone being that of the chill crystallization and of one type of crystals which extended inwardly from the four sides to a considerable depth, and another being the (enter crystallization of a different type of crystals which took place ata slower and more uniform rate. The crystals which formed on the four angular- -ly disposed walls and at substantially right angles thereto, intersect at the corners of the ingot and form distinct diagonal lines. rlhe line of meeting of the same type of crystals, as at the corn/ers, or the line of meeting of the two different types of crystals as the chill and the central crystals is` in each case quite a distinct line and forms zones known in the art as ingotism, which usually develop a weakness in tho finished work. This weakness may be due to the change and character of metal where the two different types of crystals meet,. or it may be due to meeting of crystals of the same type, but f 'having an axis, or growth, in a different direction. Either cause prevents uniformity of texture of material throughout the ingot,

and also produces a tendency for segrcgates to lodge in, or to be increased in, this zone of change of crystallization. Vherever a change 'in crystallizing structure, either in the direction of crystal growth or in the form of crystal, occurs in the ingot as a sharply defined line experience shows there is a marked change in the physical characteristics of the steel at this line. Any change in physical characteristics represents a weakness which is obviously undesirable. In top poured ingots there are further difficulties, one of which may be caused by a top crust which is developed by the Contact' of the moltenV steel with cold atmosphere, and which crust rises as the mold is filled until such time as the metal freezes and the contraction, or shrinkage of the metal in crystallizing draws down the still molten metal away from the chill top surface, thus producing a cavity and a bad end on the ingot. Aside from physical defects suchas pipes andv cavities there are a number of other defectsJ in vertically poured ingots, which defects are also due to crystallization. In vertically cast ingots the molten material is rapidly chilled or frozen from all sides while being still fed or added to with material at a higher temperature. The crystals therefore already formed or in process of formation are, `due to the higher temperature of the center, or ferro-static pressure, or both` seriously deformed with the result that a series of irregular freezings are taking place. It is this fact which leads to the accumulations of impurities in the forni of segregations; for, the crystals on taking definite shape and havingvno a-hnity for the impurities extrude same and as the outer shell is already definitely chilled or solidified the impurities have no alternative but to pass into the Ystill molten portion of the ingot. This process goes on automatically and since the center portion near the top is the last portion of the ingot to freeze obviously the bulk of the impurities 1n the form of segregations are to be found there.

The present method comprises gradually filling a substantially horizontal matrix of a chill mold with molten steel. The pool formed preferably is a relatively quiescent, pool with the molten steel heilig fed into it in suoli a manner as to supply fresh molten steel to the surface of the pool. The chilling action of the molten metal is controlled in such manner as to take place upon two sides and one end of the molten mass over a long wide area so that the chilling or freezing elfect is relatively rapid and the depth of the molten pool is slight. rlhe impurities in the liquid metal are trapped between the crystals being formed so that opportunity to segregate is, to a large extent removed and materials which usually segregate out are substantially uniformly distributed throughout the ingot.

The metal may be considered as freezing in imaginary layers or as freezing from the bottom of the pool upwardly and inwardly 'toward the center of the pool in such man ner as to maintain a relatively shallow layer of molten metal supported within an' upwardly growing frozen wide mouthed cup. This action permits of an uninterrupted or free growth of crystals and permits a large area of molten metal to supply any shrink age due to the freezing action. rlhe present method further contemplates causing the molten surface of the pool to gradually extend in area as the pool is formed up to a predetermined dimension and then to diminish in area substantially to a line or small curved surface which forms the uppermost portion of the ingot. The chilling of the molten steel in the preferred form of the present method therefore begins at the bottom of the ingot on two longitudinal sides comprising a V-shaped trough. This action continues until the widest portion of the ingot is reached, at which time the edges of the molten pool are brought into contact with overhanging longitudinal chill walls comprising an inverted Vshaped trough, which chills the marginal portions of the molten steel while the central portion of the molten steel pool loses heat at a lesser rate due to the fact that the heat from this portion of the molten metal must be absorbed by or conducted through the thickest part of the already frozen metal. During the pouring operation a very hot non-oxidizing atmosphere is quickly formed above the molten steel, so that there is substantially no tendency to form a top crust.

Preferably in carrying out the present method the ingot is slightly larger at the head, or pouring end of the mold than it is at the foot of the mold. The zones of isocrystallization beginas cupped or hammock shaped zones as the ingot is being formed and continue in this form until the largest portion of the ingot is reached, or in other words, until the overhanging'fupper walls of the mold are reached by the filling of the matrix with molten steel. The final zones in the uppermost portion of the ingot, however, are substantially closed areas. The center of the crystallizing action, and which center for purposes of convenience has herein been termed axis of crystallization, comprises a curved line beginning adjacent the foot of the ingot and extending downwardly, then extending toward the head of the ingot somewhat in the generai direction of a catenary curve. rThe lowest part of this curve is above the longitudinal center, or axis of the ingot.

lirom the foregoing it will appear that the freezing of the metal may be' described as an uninterrupted growth of crystals from the two longitudinal lowertl-shaped surfaces of the ingot practically up to the tip or top angle'of an inverted Vshaped trough. When the ingot is less than half formed, the crystals grow from the two lower dihedral angles and foot, and when the ingot is more than half formed the crystals grow from the two upper dihedral angles and foot. rllhe volume of molten metal at the top of the pool is so small in comparison with the area of chill that it freezes rapidly. The upper intersection of the inclined surfaces is inclined to-ward the head end or toward the runner, and the final freezing and filling action moves rapidly from the foot toward the head end of the pool so that molten steel is supplied to the ingot from the runner up to the final moment 'of freez- U' ing of the metal in the ingot.

lt is to be understood that the head of the mold refers to that end provided with the runner and that the foot of the mold refers to the end of the mold which is distant from the runner.

The present method may be carried out in many ways, but preferably it is carried out in a covered horizontal chill mold having a tapered matrix in a mold, the exterior of which is substantially rectangular in crosssection and with the matrix of the mold also being Substantially rectangular in crossscction and having the diagonals thereof arranged at substantially 45 degrees to the diagonals of the mold exterior. This .produces a construction having a relatively large mass of metal in the side walls ofa triangular cross-section adjacent the sides of the matrix of the mold. The exterior of the mold is substantially rectangular in a longitudinal cross-section -and the matrix preferably is tapered longitudinally so that the walls adjacent the foot of the mold are thicker than the walls adjacent the head thereof in order to cause the crystallizing action to proceed in the proper manner from the foot toward the head of the mold. The foot of the matrix preferably is a curved surface and may be formed as a part of a hollow spherical surface. A runner tile is arranged adjacent the head of the mold with an inlet opening leading into the matrix. The opening may extend partly across the matrix or may extend substantially the full length of iis-asians Y i 1 the tile across the head end of the matrix. This runner tile is provided with a supply opening of such size as to supply hot steel. to the inlet opening in sufficient volume to take care of the shrinkage. This supply opening is also of such height that the lowest level of molten steel in the riser shall at all, times be above the highest portion of the matrix in the mold. The side Walls of this runner tile are of sutlicient heat resisting capacity to prevent chilling of the steel during the period of solidification of the ingot; and with the inlet opening leading to the matrix of sufficient size to prevent the natural rimming or freezing effect from closing off the feeder until such'time as the ingot has solidified.

The principal object of the present invention is ythe method of casting steel ingots comprising causing free crystallization of the steel to be begun at the lower corner of the ingot and to proceed substantially uninter-y luptedly to the opposite upper corner of the ingot in such manner that the last portion of the ingot to crystallize comprises the upper corner adjacent the head of the ingot, and supplying molten steel to the surface of the mass during freezing and until the ingot is completely formed.

Another and further object of the present invention is the method of casting horizontal steel ingots which comprises causing the ingot to be formed from a horizontally disposed pool which starts at a lower corner of the ingot and gradually widens to the widest part of the ingot and then narrows tothe opposite corner of the ingot, and supplying molten steel in such manner as to permit the steel to freely freeze so that the molten steel which comprises a surface layer of shallow depth, and continually feeding said pool with molten steel supplied at the head of the ingot to the top surface of the pool until the ingot is completed.

A further object of the present invention is the method of casting horizontal ingots by casting the ingot so that the lowermost portion-of the ingot comprises a dihedral angle and the uppermost portion also comprises a dihedral angle then slowly pouring the molten steel in such manner as to permit uniform crystallization to build up fromI two sides to form a frozen cup enclosing a shallow pool of molten steel, with the mouth of the cup gradually becoming more narrow until the cup finally closes at the head end of the ingot, and providing a runner tile with an inlet opening of such construction as to feed molten steel to the surface of the pool until the cup closes, and then into the y molten metal in the closed cup until the ingot is .completely formed.

Another and still further object of the present invention is the method of casting staeel ingots by utilization of a horizontal chill mold having a substantially rectangular cross-sectionmatrix then gradually filling the matrix with molten steel at such a rate as to permit crystallization to continue uninterruptedly from the bottom walls of the matrix toward the top thereof with the axis of crystallization moving from the foot. of the mold toward the head thereof.

Another object of this invention is the production of an article of manufacture comprising a steel in ot having an axis of crystallization wliic 1 extends from the foot of the ingot toward the head thereof in lsubstantially the form of a catenary curve.

A -still further object of lthe present invention is the production of an ingot of steel in 'which the crystallization is substantially uniform, Without cavities or pipes except such as may arise due to the occluded gases. and` in any case, with the impurities distributed substantially uniformly throughout the ingot.

Other and further objects of the present invention will in part be obvious and will in part be pointed out hereinafter in the specification following. It is recognized that the disclosure herewith comprises but one embodiment of the present invention and therefore it is desired that the disrlosure shall be considered illustrative and not in the limiting sense.

Figure 1 illustrates an elevational view of one form of mold for carrying out the present invention.

Figure 2 is a plan view of the device shown in Figure 1.

Figure 3 is an end view looking at the head of the mold shown in Figure 1;

Figure 4.- is an end view looking at the foot of the mold shown vin Figure l;

Figure 5` is a View showing a cross-section taken on line A-A Figure 1;

Figure 6 is a longitudinal section on lines 6-*6 of Figui-e7 of an ingot castby this method;

Figure 7 is a transverse section taken on line 7-7 of Figure 6;

Referring now to the drawings, which illustrate one embodiment of the mold for carrying out the present invention, the base 1 comprises a trough-like member the lowermost portion 5 of which comprises the lower dihedral angle of corner of the matrix of the mold which is substantially horizontal when the mold is set up onv a casting floor 6, or any support common in the art which may be used to accomplish this result. The

upper half 7 of the mold is an inverted trough-shaped member comprising the upper dihedral angle or corner of thematrix and When'in position on the lower portion 1 provides an enclosed matrix 8 which is substantially rectangular in cross-section with the corners rounded or chamfered as at 9 and with the diagonals of the rectangle y is rounded as at and preferab being substantially vertical and horizontal. The base or foot of the matrix f the curvature is substantially spherical. In the preferred form the matrix 8 tapers toward the head end and the Side walls of-the mold adjacent the flat sides of the matrix comprise relatively large masses of cast iron or other suitable chill metal. The head end of the mold is so constructed that it forms a shelf or. receptacle which encloses a runn ner tile 11 which preferably is substantially rectangular in cross-section and which is provided with a relatively large feeder opening 1Q, having a capacity sufficient to insure that molten metal will be fed to the mass in the matrix, thereby providing a reservoir for supplying the ingot with molten steel during the solidification thereof. The runner tile is exposed on one side to the matrix and forms a. portion of the end matrix wall. This delays the chilling action on this portion of the ingot. The runner tile preferably is provided with an inlet opening 14 leading into the matrix and with this opening comprising a conduit which may be elongated so that as the mold fills there is always a free iow of molten steel above the filled portion to insure the flow of molten steel tothe surface of the mass in the matrix. Sufficient clearance may be allowed between the upper edge of the mold and the runner tile to provide a gas outlet opening 15 through which mold lgases may escape when the molten steel is introduced into the mold.

Referring to Figures 6 and 7 which represent diagrams disclosing a theoretical outline of the crystallization in the ingot, the zones of isocrystallization are indicated by dotted lines. The dotted lines B represent cup or hammock shaped zones, the sides of which incline upwardly and inwardly after the upper half of the ingot is reached and until the final zone C, which is substantially a closed area. The theoretical line D shown in heavy dots in Figure 6 indicates the path of the axis of crystallization or in other words it is the center line toward which the axes ofthe crystals extend. This line `be gins at the foot and extends forwardly toward the head of the ingot somewhat in the form of a eatenary curve.

In carrying out the present invention a mold matrix is preferably arranged with the bottom portion substantially horizontal so that the bottom portion of the ingot is under substantially uniform ferrostatic pressure throughout its entire length and with the upper portion of the matrix inclined toward the gas outlet so that mold gases are not trapped durin-g filling of the mold. The gradual filling of the mold together with the curved foot of the ingot and the rapid withdrawal of heat from the lpreferab ly sides of the ingot causes the axis of crystallization to proceed lfrom the foot toward the head of the ingot and allows the ingot to shrink toward the' head or pouring end of the mold. The heat gradient runs from the foot toward the head of the ingot and a sufiicient amount of molten metal is provided in the runner tile to supply shrinkage so that the last part of the steel to freeze is a small portion of the upper corner of thev ingot adjacent the inlet opening in the runner tile, therefore, the ingot is solid\ throughout. The impurities in the steel are scattered throughout the ingot in approximately uniform proportion, and the small portion of impurities or segregates which may be extended as the shallow pool freezes, passinto the molten steel in the runner tile. The natural shrinkage of the ingot from the foot toward the head or pouring end completely` prevents piping in view of the fact that the shrinkage is taken care of by the molten metal above and ahead of the crystallizing action and by the supply of molten metal inthe runner tile. Actual experiments show that the ingots cast in accordance with the present method possess increased physical strength both transversely and longitudinally, as compared with ingots cast from the same batch of steel in accordance with the practice in the prior art. The strength of the metal in these novel ingots appears to be due to the substantial elimination of cleavage planes in the crystallization formation and the absence of ingotism in the ingot, as well as elimination of such factors as disturb normal crystallization of the steel during solidification.

The mold herein disclosed as one device in which this method may be carried out, is claimed in my copending application.

Having thus described my invention,

what I cllaim is: g l. The method of casting steel ingots and the like, which comprises pouring the metal to form an elongated quiescent horizontal pool, continuing the pouring t0 supply fresh molten, steel to the surface of the pool, and chilling the pool upon four sides and the foo-t end to cause the freezing to progress toward the head end.

2. The method of casting steel ingots and the like, which comprises pouring the metal to form an elongated quiescent horizontal pool, chilling. the pool upon the foot end and the sides contacting with the mold to cause the freezing to progress toward the head end, and continuing the pouring to supp-ly fresh molten steel to the surface of the pool to maintain a relatively shallow layer of molten metal over the solidifying portions. f

3. Thel method of casting steel ingots and the like, which comprises pouring the metal Astream tov form an to gradually form an elongated quiescent horizontal pool, chilling the metal from the bottom of the pool upwardly and continuing the pouring to supply fresh molten steel to the surface' of the pool.

4. The method of casting steel ingots and the like, which comprises pouring the metal to gradually form an elongated quiescent horizontal pool, chilling the metal from the bottom of the vpool upwardly and continuing the pouring to supply fresh molten steel to the surface of the pool to maintain a rela-- the like, which comprises pouring the metal as ka substantially horizontally directed elongated horizontal quiescent pool with the edges of the pool forming a thin wedge-like cross-section of metal, chilling the botto-m portion of said wedge-like cross-section, supplying molten steel to the. surface of said pool at one end thereof, causing the chilling action to progress more rapidly at the foot of the pool `than at the pouring end thereof` and malntaining a sufficient supply of molten steel at the pouring end of the. pool to feed liquid steel lo the mass until the ingot is solidified. 7. The methodof casting steel ingots and the like, which comprises pouring the metal to form a` horizontal elongated quiescent pool. continuing` tthe. pouring to maintain fresh molten steel on the surface of the pool, and differentially chilling the mass until the ingotis formed. l S. rlhe method of casting steel ingots and the like, which comprises pouring` the metal to form a horizontal elongated quiescent pool.' dill'erentially chilling thev mass until the ingot is formed, and continuing the pouring to maintain fresh molten steel on the surface of the pool to maintain a shallow layer of molten steel over the freezing mass.

9. The method of casting steel ingots and the like', which comprises pourin the metal to form a horizontal elongatec quiescent pool, the lower sides ot' which pool comprise surfaces meeting to forni a substantially V- shaped cross-section, and the upper surfaces of the pool meeting to comprise a subst-antially invert-ed V-shaped cross-section, continuing the pouring at such rate as to main- 4tain a fresh layer of molten steel onthe surface of said pool until the pool iseompleted to form an ingot, and differentially chilling the pool until the ingot has substantially solidified. A

10. The method of casting steel ingots and the like, which comprises pouring the metal to form a horizontal elongated quiescent pool, the lower sides of which pool comprise surfaces meeting to form a substantially V- shaped cross-section, and the upper surfaces of the pool meeting to comprise a substantially inverted V-shape in cross-section, and continuing the pouring at suc-l1 rate as to maintain a shallow layer of molten steel on the surface of said pool until the pool is completed to form an ingot..

11. The method of casting steel ingots and the like, which comprises pouring the steel to form a pool having a liquid level top surface which widens at a Substantially constant rate as the pouring progresses until a predetermined dimension in width is reached, and which then diminishes in width at a substantially constant rate from said predetermined dimension until the edges of the surface of the pool approach a line, and chilling the molten steel in such manner as t0 cause the crystallization to progress upwardly and forwardly in the lower half of the pool and downwardly and forwardly in the upper half of the pool.

12. The method of casting steel ingots and the like, which comprises pouring the steel to vform a horizontally disposed elongated pool having a liquid level top surface which widens as the pouring progresses until a predetermined dimension in width is reached, and which then diminishes in width from said predetern'iined dimension until the edges of the surface of the pool approach a line, chilling side surfaces of the molten steel in such manner as to cause the crystallization to progress upwardly and forwardly in thel lower half of the pool and downwardly and forwardly in t-he upper half of the pool, and controlling the pouring to maintain a shallow layer of liquid steel over the freezing portion of the mass.

13. The method of casting steel ingots and the like, which comprises pouring the molten steel to forma pool having substantially a. rectangular cross-section with one diagonal of the rectangle being substantially vertical, chilling all of the sides of said pool in such manner that the lowest temperature llO of the pool is at the foot end thereof, and causing the chilling action to progress inv such manner that the heat gradient runs toward the pouring end of the pool.

14. The method of casting steel ingots and the like, which comprises pouring the molten steel to form a pool having substantially a rectangular cross-section with one diagonal of the rectangle being substantially the like, which method comprises pouring the molten steel to form an elongated quiescent horizontal pool having a substantially rectangular cross-section with the greatest cross-sectional area thereof adjacent the pouring end of the pool, chilling all sides of the'pool during and after the pouring operation -to cause the heat gradient torun toward the pouring end of the pool, and maintaining a supply of molten steel at the pouring end to feed the ingot during the sol1d1- cation period.

16. The method of casting steel ingots or the like, which method comprises pouring the molten steel to form an elongated quiescent horizontal poo-l having a substantially rectangular cross-section with. the greatest cross-sectional area thereof adjacent the pouring end of the pool, chilling all sides of the pool during and after the pouring operation to cause the heat gradient to run toward the pouring end of the pool, maintaining a supply of molten steel at the pouring end to feed the ingot during the solidification period, and also maintaining an enclosed volume of non-oxidizing gas over the surface of the pool until the pool is completed to form an ingot. t

17. The method of casting steel ingots and the like, which method comprises pouring molten steel to fo-rm a horizontal quiescent pool having a rounded foot end and having a substantially rectangular crosssection, withdrawing heat from the sides of said pool during and after the pouring operation to chill the metal adjacent said sides, pouring the steel into one end of the pool in such manner as to maintaina layer of fresh molten steel over the surface of the' pool until a completely formed chilled shell is obtained, regulating the chilling action to cause the heat gradient to run from thefoot of the mold toward the pouring end thereof, and maintaining a sufficient supply of molten steel adjacent the pouring end of the pool (tio feed the ingot during the freezing perio 18. The inethod of casting steel ingots and the like, which method comprises pouring molten steel to form a horizontal quiescent pool having a rounded foot` end and having a substantially rectangular crosssection, maintaining an atmosphere of nonoxidizing gases over the surface of the pool during pouring, withdrawing heat from the eration to chill sides of said pool during and after the pour-A ing operation to chill the metal adjacent said4 sides, pouring the steel into one end of the pool in such manner as to maintain a layer of fresh molten steel over the surface of the pool until a completely formed chilled shell is obtained, regulating the chilling action to cause the heat gradient to run from the foot ofthe mold toward the pouring end thereof, Iand maintaining a suicient supply of molten steel adjacent the pouring end of the pool to feed the ingot during the freezing period.

19. The method of casting steel ingots and the like, which method comprises pouring molten steel at one end of a mold to form a horizontal quiescent pool having a rounded foot end and having a substantially rectangular cross-section with the topmost portion thereof inclined toward the pouring end, withdrawing heat from the sides of said pool during and after the pouring oppouring the steel into one end of the pool in such manner as to maintain a layer of fresh molten steel over the surface of the pool until a completely formed chilled shell is obtained, regulating the chilling action to cause the heat gradient to run from the foot of the mold toward the pouring end thereof, and maintaining a sufficient supply of molten steel adjacent the pouring end of the pool Oo feed the ingot during the freezing perl 20. The method of casting steel ingots or the like, which method comprises slowly pouring the steel from a substantially horizontal stream to form a horizontally disposed elongated pool of molten steel having a rounded foot end differentially chilling the steel during and after the pouring operation to cause the heat gradient to run from the foot of the pool toward the pouring end thereof, and maintaining a sufficient supply of molten steel adjacent the' pouring end of the pool to feed the pool during solidifcation of the metal therein.

21. The method of casting steel ingots or the like which method comprises slowly pouring the steel from a substantially horizontal lstream directed into one end of a horizontal rectangular mold, having one diagonal thereof in a vertical plane, to form a quiescent elongated pool of molten steel having a rounded foot end, differentially chilling the steel during and after the pouring operation to cause the heat gradient to run from the foot of the pool toward the pouring end thereof, and maintaining a sufficient sup ly of molten steel adjacent the pouring en of the pool to feed the pool dur- 'ing solidification of the metal therein.

22. As an article of manufacture, a horizontally cast ingot of steel or the like having cupped zones of isoerystallization in the the metal adjacent said sides,

major portion thereof and closed zones of isocrystallization superposed above the cupped zones.

23. As an article of manufacture, a horizontally cast ingot of steel or the like having cupped zones of isocrystallization in the lower portion thereof and closed zones of isocrystallization superposed above cupped zones with the segregates substantially uniformly distributed throughout the ingot.

24. As an article of manufacture, a horizontallycast ingot of steel or the like having cupped zones of isocrystallization in the major portion thereof and closed zones of isocrystallization superposed above the cupped zones with the segregates substantially uniformly distributed throughout the ingot.

25. As an article of manufacture, a horizontally cast ingot `of steel or the like having an axis of crystallization extending from the foot toward the head in substantially a catenary curve.

2G. As an article of manufacture, ahorizontally cast ingot of steel or the like having an axis of crystallization extending from Y the foot toward the head in substantially a catenary curve above the axis of the ingot.

27. As an article 'of manufacture, a horizontally cast ingot of steel or the like having an axis of crystallization extending from the thev foot toward the head in substantially a catenary curve and with lines of radial rystallization extending inwardly from the oot. v 28. As an article of manufacture, a horizontally cast ingot of steel or the like having an axis of crystallization extending from the foot toward the head in substantially a catenary curve above the axis of the ingot and with lines of radial crystallization extending inwardly from the foot. 29. The method of casting metallic ingots and the like, which comprises pouring the metal to gradually form an elongated, quiescent, horizontal pool; chilling the metal from the bottom of the pool upwardly and continuing the pouring to supply successive layers of fresh molten metal to the solidify- 1^' ing portions.

30. The method of casting ingots and the like, which comprises pouring the meta-l to gradually form a pool substantially V- shaped in cross-section at its lower surfaces and with its upper surfaces meeting to comprise al substantially inverted V-shaped cross-section, chilling the metal from the bottom`of the pool upwardly and continuing the pouring to supply layers of fresh molten steel to the Jsurface of the solidifying portions.

JOHN EDMUND PERRY.

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