US1491881A

US1491881A - Method, mold, and ingot

Info

Publication number: US1491881A
Application number: US418398A
Authority: US
Inventors: John E Perry
Original assignee: Valley Mould & Iron Corp
Current assignee: Valley Mould & Iron Corp; VALLEY MOULD AND IRON Corp
Priority date: 1920-10-21
Filing date: 1920-10-21
Publication date: 1924-04-29
Anticipated expiration: 1941-04-29

Description

April 29, .1924. f 1,491,881

J'. E. PERRY f METHOD, MOLD, AND INGoT Filed oct. 21. 1920 ""munm fr www lll Patent Apr. 2, 1924.

JGHN E. PERRY, 0E SHARON, PENNSYLVANIA, SSIGNOB TO VALLEY MOULD AND IRON CORPORATION, 0F BHARPSVILLE, PENNSYLVANIA, A CORPORATION 0F NEW YORK.

Application led October 21, 1 920. Serial No. 418,398.

To all whom it may concern Be it known that I, JOHN E. PERRY, a citizen of the United States, and a resident of the city of Sharon, in the county of Mercer, State of Pennsylvania, have invented new and useful Improvements in Methods, Molds, and Ingots, of which the following is a specification.

The present invention relates broadly to metallurgy and more specially to a method, a mold and a steel ingot. p

The principal object of the present invention is the method of producing a steel ingot, the mold for carryin out the method, and the ingot resulting rom the method, wherein a smooth ingot is formed with a substantially uniform chilled shell enclosing any gas bubbles that may develop durin cooling and with the gas bubbles deep seated in the ingot.

Another object of the present invention is an ingot of steel or the like comprising a chilled shell of steel enclosing any gas bubbles that may form during cooling with the thickness of the shell sutticient to prevent the gas bubbles from breaking out during rollmg.

A Vfurther object of the present inventionv is the production of a steel ingotor the like having a chilled shell enclosing any gas bubbles that may form during cooling and with the general direction of the length of such gas bubbles being at substantially right angles to the shell wall adjacent said bubbles.

A tui-ther object ot the present invention is a steel ingot as an article of manufacture comprising an ingot having all sides thereof uniformly chilled and with the chilled zones comprising longitudinal closed areas, the maximum area comprising the surface of the ingot and the minimum area comprising a closed zone located adjacent the longitudinal axis ot the ingot.

Another object of the present invention is au ingot as an article of manufacture comprising a horizontal ingot having all surfaces thereof chilled to a substantially un* form depth and with the elements of the in got having the lowest point of fusion located in the central longitudinal portion of the ingot.

A still further object ot' this invention is the prodiuiftion as an article of manufacture of an ingot of steel or the like comprising a longitudinal ingotl having all surfaces-thereof chilled, having the metal therein substantially s ymmetrie with reference to the ends of the ingot and with the metal containing ingredients of the highest point of fusion being adjacent the surface of the ingot and with the metal containing the ingredients of lower points of fusion being located in the interior of the in ot.

A still further o ject of the present invention is the method of casting steel ringots in such manner that the highest portion of the mold comprises a part other than a flat side thereof.

Another object of the present invention is the method of casting steel ingots in such manner that a corner of the ingotcomprises the highest part of the mold during the part of the molding operation when gases are being expelled from thesteel.

Another object of the present invention is a horizontal ingot mold with one diagonal plane of the mold being substantially a vertical plane.

Another object of the present invention is the method of casting steel ingots by causing the surface area of the molten steel to Widen from the bottom of the mold upwardly to a predetermined zone and then, to gradually narrow as the metal fills the mold, until the final portion of the mold is sul stantially the apex of an angular surface.

A. still further obiect ot the present invention is the method of casting steel ingots which comprises casting the ingot with the major axis thereof substantially horizontal and with the pool of molten steel forming the ingot having a surface which gradually widens as the mold is filled from the bottom to a predetermined point, and then the surface gradually narrows 'from said bredetermined point, to the upper extremity of the mold, while permitting gases to escape from the portion of the mold `which forms the highest part of the ingot.

Another object of the present invention is the method of casting steel ingots which comprises casting the ingot horizontally, causing the upper surface ot the moltenfsteel as itills the mold to gradually narrow until the surface becomes substantially a line formed by the intersection of angnlarlydislll@ ' yio in described posed sides,l and chilling the sides of the ingot during the casting operation.

Another object of the present invention is the method of casting a steel in ot with the major axis thereof substantie. y horizontal and with a diagonal plane thereof substantially vertical, and permitting gases to esca from the mold during the castin operation at a point or points located in sai vertical diagonal plane.

A further and' 'niportant object of the present invention is a horizontal inold for.

carrying out the process specified, `which mold comprises a. multi-part structure having the maior axis of the matrix portion sub-` Other and further objects of the present invention will in part be obvious and will in part be pointed out hereinafter in the specification by reference to the accompanying drawings forming a part oft-his application and wherein like parts are represented by like characters throughout the several figures thereof. y

Realizing that the present invention may be embodied and carried out in constructions and by mani ulations other than those heredesire that the disclosure herewith shall `be considered as illustrative and not in the limiting sense.

Figure l is a view diagrammatically illusti'ating one form of mold embodying the present invention;

Figure 2 is a section on line 2--2 of Figure 1;

Figure 3 is a plan view of Figure 1, illustrating the gas outlets and showing the fountain removed;

Figure 4 is a cross-section through a mold 4 having alvertical separation lane:

Figure is a cross-section t rough a mold having one side removable; a

Figure 6 is a longitudinal section through an ingot in accordance with the present invention taken on line `6--6 of Figure 7,

Figure 7 is a cross-sectiony through an ingot in accordance with the piesent invention taken on line 7 7 of Figure 6.

` Heretofore in the steel industry ingots have been cast in various types of horizontal molds and various provisions have been suggested for maintaining the upper portion of the molten steel hot. Under such conditions it appears that the materials which tend to segregate in the coolin of the steel are ydriven toward the top an undesirable conditions may arise under certain circumstances.

' uct.

It'has been suggested in the art that steel ingots be cast in chill molds having light chill covers. It has been found that where ingots are cast in trough like chill molds with light chill covers the top surface ofthe steel, when coming in contact with the cover, tends to chill and forni a skin, then y gases being expelled from the steel during cooling become trap ed beneath this skin. These vgases form bub les which` build up in a downward direction and may form 'large subcutaneous cavities. This condition is aggravated in large ingots because the chilling effect is very slight as compared to the mass of steel in the ingotand the freed ygases are relatively large as compared to the chill ski-ii formed by the chill. These subcutaneous cavities break out in rolling land are very.

undesirable. Furthermore, in' the trough type of ingot mold it was necessary to incline the side walls of the molds slightly so that the to of the ingot would be slightly wider than te bottom to provide clearance so that the ingot might be stripped from the mold. It is desirable, for rolling operations, to have the sides of the ingot substantially parallel and the angles necessary for clearance in the trough mold prevented attaining tliisdesired cross-sectional form. It has been proposed, to provide .ingot molds with removable si des. Such molds, however, usually require a number of pieces, and often require luting the joints to prevent leakage of steel during castgfhe present invention comprising the method an ingot, and a mold, overcomes the difficulties of the known art by providing for the production of an ingot wherein the chill is proportioned around the ingot in such manner as to be substantially uniform and preferably is a quick chill so that a. relatively deep mass of solidified steel is qiiicklv formed around the ingot and wherein the entire ingot may be rolled into finished prod- Tliis invention may be carried outl in various ways butt-'in the preferred method it is carried ont by utilizing anv ingot mold with all sidestliereof formed of chill metal having a relatively large heat absorbing capacity. Preferably the mold is provided with meansv for gas escape at the highest ortion of the niold that when the mold is filled with inolteu steel the free gases are driven ahead of the liquid Surface until the mold is filled, at which ti-nie the walls of the mold quickly absorb heat from theiiiolt-eii steel, thereby quickly forming a closed she-ll of solid and plastic steel which cncloses :i mass of 4liquid steel that is in the center of the shell. The mold side walls are so proportioned as to cause the chilling operation to take place with sufficient rapidityto establish conditions within the interior 'of the ingot which prevent the formation of gas bu bles to any serious extent during the coolies ' 1,1,set

ing of the ingot. `It appears that under certain circumstances a solid steel shell will form to the depth of 1% inches or more and then a zone may form including rela-tively small gas cavities, and the interior of the in ot from that point appears to be substantifly solid metal. These deep seated gas bubbles in no way interfere with the production of rfectsteel articles from the ingot because 1t appears in rolling the gas in theseI cavities, being under pressure, 1s absorbed in the hot metal and the walls of the cavities weld together. When molten steel is poured into the mold the ingredientsy of the steel having the highest point of fusion solidify first and this material is substantially the pure steel, so that the parts which solidify rst; namely'themexterior enclosing shell, is formed substantially ofl pure steel. As the solidilication continues to take place there is a tendency to drive inward materials which fuse at a lower temperature. As the pressure increases, however, on the interior molten steel, the segregation of these ele-`, ments appears to decrease so that while the shell of the ingot is the purer steel, the interior of they ingot is good metal of a rela tively uniform constituency in which is intermingled the lower melting point elements such as phosphorus, sulphur, manganese, etc. It also appears that such gas bubbles as do appear Within the outer steel shell, are elongated bubbles which extend in a general direction at right angles to the adjacent chilled side. 1When the ingot lengthens out under the rolls these bubble cavitiestend to turn and incline in the direction of the length of the fiber of the steel thereby receiving a kneading action which assists in closing the cavities.

In one way of carryingl out this invention the ingot is cast with the major axis of the ingot substantially horizontal and with the diagonal thereof substantially vertical so that the highest portion of the mold is represented by the apex of an angle formedl by surfaces of the mold. This construction permits the escape of expelled gases through one end of the mold and in the form' where 'joint provides an air space through which the expelled gases may escape up to the final montant of solidication. However this same result is accomplished b v inclining the mold toward the gas outlet. rhe present invention, which contemplates parting the mold on a diagonal thereof, permits thel sides of the mold matrix to be made in the form of horizontal planes, which produces an ingot having substantially parallel sides, and whichv is better ladapted or rolling than the tapered ingot of the type usually made in vertical molds.

In carrying out the present invention it is not absolutely essentialthat the sides of the ingots shall be plane surfaces because v very complete escape of ga' the mold 1s parted vertically, the parting Y' under some circumstances it is desirable that the sides be curved, but in such cases where the sides are curved it is preferable that the mold be set or formed in such manner that the interior longitudinal surfaces at the top of the mold Will form an inverted V-section with the apex of the V at the highest part of the mold and with the apex angle as acute an angle as the section of the required mold will permit. It is also desirable that the two surfaces forming the above mentioned apex angle shall have about an equal angle to the horizontal. This approximate equality need not be observed when more gases seem to become entangled on one surface than on the other due to some lack of cross-sectional symmetry in the matrix ortion of the mold. In such a case theang e of the surface which tends to hold the most gases may be increased somewhat with reference to the horizontal. In no case, however, should one surface be favored over the other to s uch an extent as `to bring the latter surface to substantially a horizontal plane.

In closed chill molds for carrying out the present invention the ingot is removed broadside from the mold so consequently the mold requires at least two parts. The longitudinal plane of separation may be arranged as desired but preferably is arranged on a vertical plane so that when the steelis poured an outlet for the gases is maintained at the highest part of the mold. While the separation opening may be of suilicient size to permit the escape of gases it should not be suiiiciently lar e to permit the escape of the steel or the orming of a steel fin of appreciable thickness. Hot steel chills, however, before it will" enter into a thin or narrow joint,so that joints that are far from air tight are entirelysatisfactory so far as escape of steel is concerned. It

Will. be noted the separation joint is the -fulllength of the ingot Vand ,therefore is relatively long whilethe amountof releasedl gas is comparatively small, so thereforea ses occurs where the plane or separation is arranged ver.

tically. l t

-Referring now to the drawings and more specially to Figures l, 2 and 3, which illustrate one form of mold for carrying out the present invention, the mold may comprises multi-part constructions but preferably comprises two parts such as a lower part l and an upper part 2 with the matrix 4 thereofpreferably comprising a form with smooth sides-forming a rectangle in crosssection. Preferably the corners are slightly rounded in order to prevent sharp angular corners on the ingot. The matrix portion 4 of the ingot is arranged preferably in Vsuch manner that one diagonal thereof is vertical and the other diagonal thereof is horizontal. p

The major axis of the matrix preferably inclined slightly to the orizontal with the inclination toward the gas outlet presently to be described.

The walls around the matrix portion are thickened at the sides thereof in order to increase the heat absorbing capacity and produce a deep uniform chill in the ingot.

referably the thinnestl portion of the Wall is adjacent the corners of the matrix which include the horizontal dia onal. The two ortions of the mold ma e held together y suitable clamps 5 whlch are adapted to engage lugs formed on the'body ortions of the mold. One end of the mol is raised and provided with an opening 6 in which a runner of fire clay or the like is adapted to be set. This runner is provided with a lowerinlet opening 7 and an upper inlet opening 8. A suitable fountain 9 is mounted above the runner in such manner as to guide molten steel into the opening inthe runner. The body of the runner preferably is slightly smaller than the opening in the mold so that s outlet passageways 10 and 11 are provi ed around the runner and connecting

gas outlet openings

12 and 14 are provided beneath the fountain.

, These connecting openings are arranged to discharge over the mold and von each side thereof in order that the fiames therefrom may be observed by the workmen. The upper portion of the mold ma .be provided with a suitable lifting stap e 15 andthe lower rtion with suitable supporting legs 16 an 17 which are so proportioned as to slightly incline the axis of the mold toward the end provided with'the gas outlet openings. When molten steel is oured into the runner the initial escape of t e steel is from the outlet opening 7 and the flow is' subl rstantially parallel to the axis of the matrix portion so that the steel strikes the mold some distance from the runner opening 7 and immediately forms .a Achilled skin on which the continuingl steel pours so that the hot steel does not cut away the walls of the cast iron chill mold. As the mold fills the gases comprising the 'original air in the matrix and the gases being expelled during cooling of the steel, rise into the matrix space above the surface of the steel and in view of the fact that gas passages are provided around the runner, the gas esca s through these passages and comes out neath the fountain through vthe conduits provided. lThese passages while ample for the gas escape are sufficiently narrow to revent any appreciable amount of steel oW- steel and the outlet u ortion is lhighest end of the mold, which is the runner end. As the molten steel continues to flow into the mold the surface of the steel begins to widen out as the steel surfaces' per portions of the -matrixwalls so that as the steel rises and iows upwardly and inwardly along the inclined walls the gases in the molten steel are swe t out and escaping throu h the surface o the molten steel are then driven from the mold cavity out through the gas outlets. The end of the matrix farthest from the gas outlet being lower, is filled first and as the teeming is continued the line of contact of molten steel with the final surfaces of the matrix moves from the farther end toward the gas outlet which is adjacent the runner 8 and therefore is adjacent the hot molten steel last to come into the mold. This provides that gases may escape through the hot molten to the moment the mold is entirelyv fille Consequently substantially all gases are swept clear from the mold before the mold is completely filled. In the teeming operation the workmen pouring the steel watch the flames shooting from the openin s 12 and 1.4:l beneath the fountain and w en these fiames cease it is an indication that the mold is filled and no more gas is escaping, at which time the teeming operation 1s stopped.

Since the side walls of the mold are proportioned to provide a large heat absorbing capacity which isV substantially uniform around the mold matrix, an enclosing shell of chill steel quicklyforms from the molten mass and builds up in thickness so that if the occluded gases in the steel are not completely driven from the steel before the mold is filled these gases are enclosed by the shell and are driven inward under pressure from the enclosing solidifying steel walls. It sometimes happens that a zone of gas bubbles will thus be formed an inch and a half or more from the outer wall of the ingot. As the ingot continues to cool pressure conditions are changing in the ingot and it apars that no further gas bubbles tend to orm so that the center ofthe ingot is substantially solid metal.

When the 4clamps are loosened and the mold o ens, the runner tile leaves the mold with t e ingot, since the runner tile sets tightly against the ingot therunner tilev inlets are short and the scrap therefore 1s relatively small.

Figure Gis a longitudinal section through en ingot on which are indicated zones A, which represent zones of isocrystallization. lt will be noted that these zones are closed shell like areas which are substantially coincident with the general shape of the ingot and are substantiall uniform for both ends of the ingot asrwe as substantially symmetrical to the axes thereof. The zone B indicates a zone of gas bubbles and shows the general direction of such bubbles as being at right angles to the surface of the in ot adjacent thereto.

igure 7 is a cross-section through an ingot in accordance with the present invention likewise indicating the zones of isocrystallizat-ion A and the gas bubbles B and withw the corner C' thereof being that portion of the ingot which occupies the uppermost part of the mold matrix. From these views it will appear that the isocrystallization zones' are substantially symmetrical to the axes of the ingot and with the zones comprising closed areas. In this ingot the outer shell is substantially pure steel and the materials which otherwise would segregate are forced inward during the cooling action, and since pressure conditions on the interior of the ingot change during cooling, segregation seems to be prevented and substantially uniform metal occurs in the middle of the ingot.

The present invention provides a steel ingot wherein all sides thereof are smooth and comprise rolling surfaces, and the gas bubbles such as form are so deep seated in the ingt that rolling we'lds the cavities together and therefore the present ingot is adapted to be rolled into a substantially one hundred per cent product thereby obviating loss due to cropping of the ingot.

Having thus described my invention, what l claim is:

1. As an article of of steel or the like having a substantially uniform deep chilled shell on all longitudinal sides andlat both ends and with the chill being substantially symmetric throughout the length of the ingot. i

2. As an article of manufacture an ingot of steel or the like havin a substantially uniform deep chilled shel on all longitudinal sides and at both ends and with the chill being substantially symmetric throughout the length of the ingot, with the sides and ends of the ingot smooth and substantially all gas bubbles being deep seated therein so that said ingot may be rolled into finished product without cro ping the ingot.

3. As an article of manu acture an ingot of steel or the like having a substantially uniform chilled shell on all sides and at both ends and with the chill being substantiallyy symmetric throughout the length of the ingot, with the sides and ends of the ingot smooth and substantially all gas bubbles 5 being deep seated therein between the outer manufacture an ingot` shell and asolid metal core containing a higher percentage of metalloids than the chilled shell.

Il. As an article of manufacture a steel ingot having smooth sides and ends with all sides and ends uniformly dee chilled.

5. As an article of manu acture a steel ingot having smooth sides ,with all longitudinal sides uniformly deep chilled and having a solid metal core containing a hi her percentage of metalloids than the deep chilled sides.

6. The method of casting steel ingots hav-- ing a plurality of longitudinally extending sides which comprises casting the ingot with the major axis thereof substantially horizontal and with the apex of the an le formed by two sides thereof comprisin t e highest portion of the mold into whic gases may collect, draining the gases from the mold adjacent a portion of said apex, and chilling the opposite ends of the ingot at substantially the same rate. I

7. The method of casting steel ingots having a plurality of longitudinally extending sides which comprises casting the ingot with the major axis thereof substantially horizontal and with the apex of the angle formed by two sides thereof comprising the highest portion of the mold into which gases may collect, draining the gases from the mold adjacent a portion of said apex, and chilling the sides and ends of the ingot at substantial'- ly the same rate. v

8. The method of casting steel ingots or the like which comprises casting the ingot with the major axis substantially horizontal and with a diagonal axis substantially vertical introducing steel adjacent the highest portion of one end of the mold land causing expelled gases to escape from the mold at the same end thereof at which the molten steel is introduced.

9. The method of casting steel ingots or the like which comprises casting the ingot with the major axis inclined slightly to the horizontal and-with a diagonal axis substantially vertical. introducing molten steel adjacent the highest portion of one end of the mold, and causing expelled gases to escape from the mold at the same end thereof at,

which the molten steel is introduced.

l0., The method of casting steel ingots having a plurality of longitudinally extending sides which comprises casting the ingot with the major axis thereof substantially horizontal and with the apex -of the angle formed by two sides thereof comprising the highest portion of the mold into which expelled gases may collect, and draining the expelled gases from the mold adjacenta por-l tion of said apex.

il. The method of casting steel ingots having a plurality of longitudinally extending sides which comprises casting the ingot i with the major axis thereof inclined slightly ,ing the highest portion of the mold into which expelled gases may collect, and draining the expelled gases from the mold adjacent a portion of said apex.

12. The methodof castin steel ingots having a plurality of longitu inally extending sides which comprises casting the in ot with the major axis thereof substantia ly horizontal and with the apex of the angle formed by two sides thereof comprising the hi hest portion of the mold into which expeled gases may collect, pouring the steel 1n such `manner as to cause the steel to rise vertically and to sweep as bubbles from beneath the angularly isposed sides, and draining the expelled gases from the mold adjacent a portion of said apex.

13. The method pf casting steel ingots andthe like comprising casting the ingot with the major axis thereof substantially horizontal and with the lowermost portion of the ingot comprising the apex of an angle forming an edge by the meeting of two sides of the ingot and with the uppermost portion of the ingot comg'ising the apex of an angle also formed by te meeting of two sides of an ingot.

14. The method of castingsteel ingots and the like comprising casting the ingot with the major axis thereoie substantially horizontal and with the lowermost portion of the ingot comprising the apex of an angle forming an edge by the meeting of two sides of the ingot and with the uppermost portion of the ingotl comprising the apex ofan angle also formed by the meeting two sides of an ingot, and uniformly chilling the steel upon all sides of the ingot to cause gas bubbles to be deep seated therein. Y

15. The method of casting steel ingots which comprises casting the ingot with the major axis thereof substantially horizontal I and with a diagonal axis thereof substantially vertical, and permitting gases to escape from the mold during casting through an opening arranged to lie substantially on said diagonal axis.

16. The 'method of casting steel ingots which comprises setting a closed horizontal mold with a diagonal of the matrix portion vertical and the longitudinal axis inclined Slightly to the horizontal, then filling the matrix with molten steel.

17. The method of casting horizontal steel' ingots which comprises fiowing the molten steel from a plurality ot openings in different vertical portions of a. single runner,

into a chill mold matrix hav-ing the longiferent vertical portions of a single runner, in-to ya chill mold matrix having the longitudinal axis inclined to the horizontal and permitting the mold gases to escape around the runner.

19. T-he method of casting horizontal steel ingots. which comprises flowing the molten steel into a mold matrix from a plurality of openings arranged at different vertical heights, and providing la gas outlet extending across one end of the matrix in such manner that said outlet is sealed as the steel rises.

20. The method of casting horizontal steel ingots which comprises flowing the molten steel into a mold matrix from a runner having a .plurality of openings arranged at different vertical heights, and providing a gas outlet around the runner and? extending across one end of the matrix in such manner that said outlet is sealed as the steel rises. v

21. An ingot mold `for casting horizontal ingots comprising a plurality of sections with the separation plane of said sections arranged on a diagonal of the matrix portion of the mold and with the hiefhest part of the matrix portion of the mold ing the apex of an angle formed by two sides of the matrix.

22. An ingot mold for casting horizontal ingots comprising a plurality vof sections with` the separation plane of said sections arranged o n a diagonal of the matrix portion lot the mold and with the highest part of the matrix portion of the molt comprising the apex of an anl le formed by two sides of the matrix andg having the longitudinal axis of the matrix inclined slightly to the horizontal.

23. Anv lingot mold for casting horizontal ingots comprisin a. plurality of sections with the separation pla-ne of said sections varranged on a diagonal of the matrix portion of the mold and with the highest part of the matrix portion of the-mold comprising the a x of an angle formed by two sides of t e matrix .and having the longitudinal axis of the matrix inclined slightly to the horizontal and with the outside surfaces of the mold being substantially inclined at forty-.five degrees to the plane of adjacent side surfaces of the matrix to provide walls having large heat absorption capacity adjacent the side of the matrix.

24. A mold for casting steel ingots having walls to chill the ingot and with a seotion of the mold wall adjacent a. matrix surface being substantially triangular to provide a uniform chill around the matrix and to cause the sides of an ingot to chill at substantially the same rate as the corners.

25. A mold having a body portion with amatrix to cast an ingot,'said body portion being formed with an opening to reliu ceive a runner, and a runner extendin into said opening with a plurality of disc arge outlets in said runner and located' at different vertical heights.

26. A chill mold for casting horizontal ingots that are polyhedral in cross-section, with the heat absorbing capacity of the walls of the mo'ld being high and so proportioned that the sides of the matrix of the mold will absorb heat at substantially the saine rate as the corners thereof.

27. A chill mold for casting steel ingots with the matrix arranged therein with one diagonal of the matrix being substantially vertical and another diagonal being substantiall horizontal and with the walls ofi the mol arranged to have a heat absorbing capacity which is greater at the ends of the said vertical diagonal than at the ends of the horizontal diagonal.

28. A chill mold for horizontal in ots having a matrix therein and with the eat absorbing capacity of the mold walls being slightl, greater in the upper half of the mold t ian iii the lateral portions thereof to provide a deep chill on the top of the ingot and cause gas bubbles to be ldeep seated therein.

29. The method of casting steelingots which comprises causing the steel to form in a pool the surface of which first increases in width and then decreases in width, symmetrical portions being formed during the decreasing and increasing stages, then quickly chilling the metal in the oolin such manner as to drive a portion o the metalloids toward the central part of the steel mass and to enclose occluded gases within the steel mass.

30. The method of casting steel ingots which comprises providing a substantially horizontal mold having a substantially square cross-section matrix, arraiging said matrix with one dia onal thereo su stantially vertical, uickly filling said matrix with molten stee and maintaining the steel mixed during the filling o eration, then quickly chillin the exterior o the steel mass to form a shel enclosing the molten interior and causing the shell to cool with sufficient rapidity to establish internal pressure on the molten mass to prevent formation of gas bubbles near the surface of the ingot. n

3l. The method of casting steel mgots which comprises casting the ingot in a substantially horizontal mold through a removable runner at one end of the mold matrix which runner is ada ted to leave the mold with the ingot when t e mold is opened after the in ot is frozen.

32. an article of manufacture comprising an ingot chill mold adapted to enclose all sides'of the ingot and having a substantially rectangular cross-sectional to the matrix, the chill metal in the sides of said mold being uniformly pro ortioned soas to absorb heat at substantial y the same rate as the corner portions of the mold between said sid.

33. As an article of manufacture an ingot of steel having rollings surface throughout the len hthereof comprising an inner core of a higher percentage of inetalloids than the outer surrounding portion or shell and with the as bubbles in the ingot confined to a zone ying between said core and shell.

34. An article of manufacture an ingot of steel comprising a. core containing a higher percent of metalloids than the outer shell of the ingot and with a zone of gas bubbles confined to a portion between the core and shell, with the gas bubbles disposed said sections arranged one above the other on a dia onal of the matrix portion of the mold an with the highest part of the matrix portion of the mold comprising the apex of an angle formed b two sides of the matrix.

37. A chill mo d for casting horizontal ingots comprising a substantially rismshaped matrix bounded by chillin en walls and chilling side walls, and wit a corner of said matrix forming the highest part thereof.

J GHN E. PERRY.