US1767174A - Ingot mold and ingot - Google Patents

Description

Jun'e 24, 1930.

E., GATHMANN INGoT MOLD AND INGoT Filed Aug.. l2. 1929 3 Slxeecs-Shet 1 v attorneys.l

Patented June 24, 1930 UNITED STATES PATENT oFFicE EMIL GATHMANN, OF BALTIMOR, MARYLAND INeoT Morin AND TNGoT AApplica'cionled August 12, 1929. Serial No. 385,343. l

This invention relates to certain improvements m metallic mgot molds having substantially vertical ingot-forn'iing chambers;

the contour of the sides of the ingotsV formed therein of thegeneral kind shown` described,

and claimed in my U. S. PatentsNo. 1.061,- 467, of May 13, 1913, No. 1,410.535, of January 2, 1923, No'.

1924, No. 1,532,741, of April 7, 1925.v and No. 1,719,543', of July 2, 1929, 1,745,089 of Jan. 28, 1930 and 1,757,663 of May G, 1990.

In the patents before referred to, I have shown and described mold contours adapted to produce ingots With fewer surface flaws or defects than are inherentv in ingots produced in the usual rectangular molds having straight-sided or plane Walls, or even' in the 5 symmetrically corrugated or luted molds of the octagon or dodecagon types of the kind illustratedin U. S. Patent No; 621,646, issued to H. L. Gantt March 21, 1899. J

The object" of my present invention is to improve the contours of the chambers of molds of the general type shown in my Patent No. 1,719,543, and, according to my invention, I increase in a-novel way the number of salients and inwardly bellied portions of .35 the chamber Walls, thus lengthening the perimeter of the cross section of the mold chamber for any given cross sectional area of the ingot to be produced. In this Way I am enabled to obtain a'tougher and more homo'- geneous skin solidification in the ingot and to thus avoid the formation of tearsin the skin While the ingot is being cooled in the mold, and, at the same time, I retain the advantages arising during the initial ,roll passes in the reduction of the ingot into blooms and other shapes, which advantages areobtainable by the use of the calnbered type of mold of generally rectangular cross section of the kind shown in my patent ofiMay 13, 1913.

My improvements may be embodied in any 1,484,940, 0f 'run-nary 2e,-

typc of vertical mold, that is, in big-end up molds, in big-end-down molds, and in those having parallel chamber walls. Molds constructed in accordance with my invention may be used for the production of ingotsl of any grade Lof steel that may be required and may be used either with or without shrink head portions. A

It is a proven fact that increasing the perimeter of the mold matrix for a given cross sectional area increases the rapidity of the extraction of heat from the outer portion of the ingot metal 'and thus hastens skin formation to such a degree that the initial walls of the ingot will be of sullicient strength to withstand the ferrostatic pres# sure of the liquid interior of the ingot during the expansion of the mold and prior to any appreciable contraction of the ingot, and this fact has been borne in mind in designing the contour of my improved mold. A

The specific contours of the walls defining the matrix of an ingot mold govern the type and rate of initial or skin solidification of an ingot. By properly increasing the cross sectional area of the matrix of a mold for a given volume of ingot, the rate of cooling is expedited, since 'the ratevof soliditication is directly proportional to the ratio of the contact area of the Walls of the mold chamber to the volume of the ingot metal cast therein.

Broadly speaking, according to my present invention the contour of the Walls of the mold matrix is vformed by a plurality of salients including a series of smoothly curved connected inwardly bellied or arcshaped Wall portions and a plurality of outwardly bellied arc-shaped Wall portions, the are defining each of said Wall portions be- .ing described by a radius of substantiallyl greater length than the chord of the are. The mold chamber includes at least two oppositely disposed primary side Walls, and'- each ofi-these Walls preferably includes two inward., @bellied orarchedwalls andthree outwaii ly bellied or arched Walls, although this number may be increased when the mold is of large cross sectional dimension or jwhere it has a slab-like contour of the type described in my copending application No. 365,455. i

In rolling ingots of the contour above described, the relatively narrow primary side walls are swedged outwardly to a large extent parallel with the axis of the rolls rather than lowedlongitudinally, as happens in` an ingot when the primary side walls are wide and the adjacent corners are in substantially the same plane as the primary side walls. The free, unworked adjacent walls are thus deformed only slightly, if at all,during the initial passing of the ingot through the rolls.

In the accompanying drawings:

Figure l shows a vertical sectional view of an ingot mold of the Gathmann big-endup type provided with a shrinkhead casing, the matrix of both the mold and casing being constructed in accordance with my invention, the bottom closure plug being shown in elevation and the stool in section.

Figure 2 is a cross sectional view on an enlarged scale taken on the line 2-2 of Figure 1.

Figure 3 is a perspective View. of an ingot formed in a mold of the type shown in Figures 1 and 2.

Figure 4 is a view on an enlarged scale and in horizontal section of a quarter portion of the mold shown in Figures l 'and 2.

Figure 5 shows on an enlarged scale a cross section of the ingot shown in Figure 3.

Figure 6 shows on an enlarged scale. a perspective view of the shrink head casing shown in Figure 1 for forming the feeder or shrinkage portion of the ingot.

Figure 7 is a view on an enlaroed scale and in horizontal section of a modi'tied form of mold chamber.

Figure 8 is a view on an enlarged scale and in horizontal section of another modified i The mold top consists of a casing S made' form of mold chamber. Figure 9 is a horizontal sectional view of an ingot cast in a mold of the kind Vshown in Figure 7, and

Figure 10 is a horizontal sectional View of' an ingot cast in a mold of the kind shown in Figure 8.

of generally rectan ular cross section and which is constructe of heat absorbing material of suitable character such as-cast iron land which rests on a stool B having a recess or trough Bof the kind shown in my U. S. Patent No. 1,039,725, of October y1, 1912.

of heat conserving material, preferably fire brick or the like.

The chamber of the mold A includes four primary side walls generally designated Q which are arranged in pairs of oppositely disposed parallel side walls, eight secondary corner walls E, each having one of its ends connected to an adjacent primary side wall Q, and four outwardly arched corner walls 4F intervening between and connecting the vidual wallsand the walls of each pair areA perpendicular to the walls of the other pair. The m'old walls at V adjacent the primary side walls Q of the mold chamber are preferably thicker than the mold walls at V adjacent the secondary corner walls E of the chamber, and the mold walls at V are preferably thicker than the mold walls at V adjacent the outwardly arched corner walls F lof the mold chamber for the purpose specifically set forth in myl patent of July 2, 1929. N-N and NN indicate neutral lines of eripheral shrinkage and pass at right ang es to each other through the center of the mold and are parallel to' As shown in Figuresl, 2, and 4, each of the primary side walls Q includes three spaced outwardly bellied wall portions Df-D-D and two intervening inwardly bellied Wall portions C-C. The primary side walls are so arranged that each intermediate outwardly bellied wall portion D has its apex on or near the neutral linel of shrinkage passing through the particular side wall of which the wall portion D is a part.V

The inwardly bellied portions C and the outwardly bellied portions D and D of each primary side wall Q are preferably each described by aradius greater than the chord of the arc defining the wall, and the depth ofthe are defining each wall in a mold of Figures 1, 2, and 4 illustrate a mold A' twentyinches diameter,lthat is, the distance from the apex of the arc to the chord thereof, is preferably between one eighth of an inch to three eighths of an inch. In each primary side wall the three outwardly arched wall portions are so disposed that a line tangent to their apexes will be perpendicular to a line tangent to the apexes of the outwardly arched wall portions of an adjacentprimary side wall. Thus a, line L-L tangent to the apexes o-f the outwardly arched wall portions D-D-D of the pri-- mary side wall Q shown in the upper part of Figure 2 is perpendicular to a line L-L tangent to the apeXes of the outwardly arched portions of the primary vside wall shown at the left in Figure 2. The Width d of each primary wall portion is preferably one third or less than one third of the maximum cross sectional dimension of the matrix in a direction parallel to that primary wall, vand the width of each inwardly bellied portion C of each primary wall is approximately one y sixth of the inaximumcross sectional dimension of the moldchanber.

In big-end-up molds the concavo-convex or tluted portions of the primary side walls should extend into the necked-in portion of the mold and merge or disappear therein as shown in Figure l of the drawings and as shown and claimed in my U. S. Patent No.

j 1,532,741, of Apri17, 1925.

The eight secondary corner walls E-E are connected together in pairs by the four outwardly arched primary corner walls F, and the secondary corner walls E are in turn connected to the outwardly arched portions D of the primary side walls Q. Each of the secondary corner wallsE extends outwardly from the adjacent corner wall F to the adjacent primary wall Q at an angle of less than fteen degrees toa tangent connecting the apexes of a pair of the outwardly bellied portions D-D at the opposite sides `of an adjacent primary side wall Q, as shown in Figure 4. lThe arc defining the primary corner walls subtends an angle of more than ninety degrees but less than a hundred and twenty degrees, as shown in Figure 4, and each of the arcs which respectively define the curved portions Aof the concaVo-convex'prirnary wall subtends an angle of less than forty-five degrees.

Figure 7 shows a modified contour of the corner walls is shown as including two inwardly bellied wall portions E and an intermediate outwardly bellied wall portion E disposed between and connecting the adjacent ends of the inwardly bellied portions E', the othervends of which portions are respectively connected to the adjacent outwardly arched corner wall F and to the adjacent primary side wall Q', each of which has a contour similar to the contour of the side walls Q of the mold shown in Figures 1, 2, and 4. Adjacent outwardly arched corner walls F are connected toner walls E each o which vhas one of its -ends connected'to one of the corner walls F, and each of which has its other end connectedjto the adjacent wall E by means of an outwardly curved salient or wall X.

In some types and sizes of molds constructed in accordance with my invention, it is not' necessary that the secondary side walls of the mold chamber be of inwardly bellied contour. Thus a large mold used for producing ingots of slablike contour may be constructed as illustrated in Figure 8. The mold illustrated in this figure has a chamber contour' similar to that of the mold illustrated in Figure v7 with the exception that each of the secondary corner walls adjacent a primary side wall Q includes two straight secondary wall portions Eiv-Evand an intermediate inwardly bellied wall portion E"i disposed between and connecting adjacent ends`of the straight portions Ei" and EV. Preferably, each of -the straight wall portions Eiv extends at an angle of from two degrees to seven and a half degrees to a line tangent to the outwardly bellied portions of the adjacent primary side wall Q', and each iof the straight wall portions Ev extends at an angle of from live degrees to fifteen degrees to such a tangent.

Employment of the before-mentioned radii and iuted contour of the primary side walls induces a freer and more rapid shrink age and consequently a more rapid solidication of the outer skin or contacting portion of the soli'difying ingot without danger of causing physical binding of the skin portions of the ingot with the chamber walls of the mold.

The ingot produced in such a mold is of a of corner burning and the surface of the ingot will be vmore readily consolidated during contour that may be reheated without danger the initial passes of the rolling mill o'perations as the flow ofv metal in these passes is primarily of a sidewise nature and without any material elongation of the ingot as a whole.

Figures 3 and 5 illustrate an ingot I which has been formed in a mold chamber of the type shown in Figures 1,2, and 4 and hcretions O, and each of' these secondary corner portions extends at 'an' angle of less than fifteen degrees to a tangent connecting the apexesof a-pair of the saliente H-H at the opposite sides of an adjacent primary side R. The arc defining each of the arched Acorners P subtends an4 angle/of more than ninety degrees, while the arc defining each of the concave-convex portions of the primary sides R subtends an angle of less than forty-five degrees.

Figure 9 shows an ingot I of slab-like cross section which has been formed in a mold having a chamber contour of the kind illustrated in Figure 47 and hcreinbefore de! scribed. rIhe sui'face of this ingot includes two oppositely disposed primary sides It each having a contour similar to the contour of the primary sides R of the ingot shown in Figures 3 and 5 and liereinbefore described. The primary sides R of the ingot I are connected to adjacent outwardly arched corners P by means of secondary side or corner portions each of which includes two inwardly bellied portions O and an intermediate outwardly bellied portion O disposed between and connecting adjacent ends of the inwardly bellied portions O. v Adjacent corner portions I are connected by a pair of secondaryv corner portions and an intervening outwardly arched salient T.

Figure 10 illustrates an ingot I" of slablike cross section which has been cast in a mold having a chamber contour such as that shown in Figure 8. The contour of the ingot I is similar to that of the ingot I hereinbefore described in detail with the exception that, instead of being provided with secondary side or corner portions `each including a plurality of curved salients, each of the secondary side or corner portions of the ingot I includestwo-straight secondary side or corner portions Oiv and Ov and an iuteriamliate inwardly bellied connecting salient O". Preferably each of the straight portions Oiv extends at an angle of from two degrees to seven and a half degrees to a line tangent to the outwardly curved salients of the adjacent primary side R; and each of the straight portions Ov extends at an angle of from five degrees to fifteen degrees to such a tangent.

An important radvantage resulting from use of my multiluted or corrugated primary mold chamber walls and of the ingot cast therein consists in the production of an ingot having vertically extending concave-convex salients on the neutral lines of shrinkage of the ingot, these salients servin to hasten solidification in that portion o the ingot where the skin in ingots heretofore known tofithe art has formerly been thinnest and consequently weakest atall times during the i period of solidiication.

A further advantage of my improvements arises in the-rolling mill, where, because of i my concavo-convex primary ingot faces, the

central portion of the ingot may be subjected to agreater degree of compression than any other type of corrugated or liuted ingot heretofore known to the art, without danger of the rupturing of the skin of the ingot. 0

It is to be understood that the action 'of rapid cooling` and soliditication of the ingot through contact with the mold chamber walls is only temporary and ceases after the mold has become heated throughout and has primary faces of the ingot.

It is not intended to limit the inventio to any specific construction or general shape of cross s'ection of molds except insofar asI relates to the novel concave-convex contour of the primary walls of the mold chamber and of the ingot cast therein as defined in the claims.

It will be observed that each of the oppositely disposed side walls of the mold is relatively thick as compared with the corner walls, and that each of said sidewalls is rovided with a plurality of inwardly be ied curved corrugations or flutes. In this way the rate' of 'cooling ofthe ingot adjacent the side walls is materially increased. This increased rate of cooling is caused not only by the greater thickness of the side walls of the mold, but by the larger contact surface with the molten metal afforded bythe lines of curvature of the corrugations.

I claim: Y

l. An ingot mold with a chamber of substantially rectangular horizontal cioss section having two sets of oppositely arranged relatively narrow primar four sets 'of inwardly be lied corner walls which are connected to the primary walls and ,to each other by outwardly extending salients, each of the oppositely disposedjside walls being relatively thick as compared with the .corner walls and each of said side walls being provided with a plurality of inwardly bellied curved corrugations or utes whereby the rate of ,cooling of the ingot adjacent said side walls is increased.

2. A metallic ingot having two sets of opl' positely arranged relatively narrow primary sides and four outwardly arched corners connected to the primary sides by inwardly curved sides, at least two of the oppositely arrangedy primary sides being provided with a plurality of inwardly bellied corrugations,

side wallsv and the chordof the arc of each of which is less vthan E.the radius from which said arc is struck. y

3. A metallic ingot having two oppositely disposed relatively narrow sides of smoothly curved concaVo-c'onvexl contour, each of said sides including*` a plurality of connected and alternately arranged inwardly bellied portions and outwardly bellied portions,

4; A metallic ingot having two oppositely disposed narrow sides, the width of each of i which is not greater than one ythirdof the maximum cross sectional dimension of the ingot vand each of which is of smoothly curved concave-convex contour, cach of said sides including a plurality of connected and alternately arranged inwardly bellied por. tions and outwardly bellied portions.

5. A metallic ingot having two oppositely ,disposed relatively narrow sides of smoothlyv curved concave-convex contour, each 'of said sides including a plurality of connected and alternately arranged inwardly bellied portions and outwardly bellied portions, one of '20 the outwardly bellied wall poi-tions of each primary slide having its apex located on the neutral llne of shrinkage passlng through the ingot and perpendicular to said primary side'. t

6. A metallieingot having two'sets of oppositely arranged relatively narrow primary sides and four outwardly arched corners connected to the primary sides by secondary sides, at least two of the oppositely arranged sides being. provided with ,a plurality of alternate smoothly curved inwardly bellied and outwardly bellied corrugations.

7. A metallic ingotv having two sets of oppositely arrangedrelatively narrow' primary sides and four outwardly arched corners connected to the primary sides b. secondary sides, at least two of the opposite y arranged Sides being provided with a plurality of alternate smoothly curved'inwardly bellied v@and outwardly bellied eorrugations, the

apexes ofthe outwardly bellied corrugations of each of the primary sides of the ingot lying in substantially the same straight line. v In, testimony whereof, I have hereunto `subscribed my name. y

EMIL GATHMANN.

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