US2495992A - Ingot mold and hot top - Google Patents

Description

Jan. 31, 1950 w. w. URMETZ meow MOLD AND HOT TOP Filed June 28, 1946 w-mm x 7 D"; a 2 6W H613 12 INVENTORQ. WALTER W URMETZ BY iii i m I can UNITED STATES rarest INGOT MOLD AND HOT TOP .Walter W. Urmetz, Parma, Ohio, assignor to The Ferro Engineering Company, Cleveland, Ohio, a corporation of Ohio Application June 28, 19%, Serial No. 680,260 a 6 Claims. (01. 22-139) 1 2 This invention relates to improvements in shoulders of the mold form strong walls against killed steel ingots and to a method and apparatus which the heavy pressure exerted by the growfor casting the e, ing metal expcnds itself, thereby pressing the Killed steel ingots are cast in molds provided gas in the metal away from the skin of the ingot with hot tops in order that a pool of molten and toward the axis thereof. metal may be maintained to flow downward and The necl ing-in of the mold in accordance fill the cavity or piping which tends to form in with my invention is for an entirely different the upper end of the ingot, centrally thereof, as iurposc, and the shouldered portions need not contraction or shrinkage occur due to cooling. be thick and strong since in killed steel ingots solidification of some of the metal originally 10 here is no heavy pre ure to be resisted. In held in the hot top takes place unavoidably, and h c o my nv n h -in p r ions then constitutes what is known in the art as a are o t 6 p p o ccom dat g a relasinkhead. Since the sinkhead is waste metal lively small and efilciently designed hot p. and and must be cropped off, it is obviously desirable in order to provide an end contour for the ingot to limit its mass as much as conditions will per- 5 hich will maintain at a minimum the cropping mit. However a certain minimum height of hot necessary f er rollin top is necessary in order to maintain a proper An object of the invention therefore is the head of metal to insure rapid flow, and a certain provisi n of a new meth nd m ans for as in minimum content of hot topped metal is necesingots 0f killed Steel m fi y. to give sary to make sure that the molten metal in the a greater y d of usable metal.

hot top will not be entirely expended before Another object is the DIOViSlOH Of a novel and. freezing of th i t body is completed useful combination of hot top and necked-in This minimum hot top capacity varies somemeld, for the p p Sta d. what with the grade of steel, but the important A fur h r object is the pr on of a killed factor is the degree of insulation provided by steel ingot of a m which may be rolled cmthe hot top. With a hot top body or lining of ciently- I high insulating quality the size of the hot top Other objects and features of novelty will apmay be reduced with a consequent importanfl; pear {S I proceed With the description Of that saving of nu embodiment of the invention which, for the In accordance with the present invention the Purposes of the Present application, I have 11- mold is formed big end down, and is necked-in lustlated in the accompanying d n n which t it upper end and provided t a central Fig. 1 is a vertical sectional view through 9. opening which may be of considerably less area slab mold and hot top embodying the invention. than the cross-sectional area of the ingot. A the View being taken through a Cen al plane n t top is disposed in perative relation m t between the wide sides of the mold, as indicated opening. The shoulders formed in the ingot body by the line of i by t neck1ng in may be given contours such Fig.3 is a vertical sectional view at right anas to minimize fishtailing, following approved gles to that of 1, as indicated y the line practice for the bottom ends of ingots. of

The present invention has special advantages 3 is a P View of the mold and 110? in connection with slab molds, for the neckingand in of such molds may be principally or entirely Fig. 4 is a fragmental vertical sectional view from the narrow sides of the mold, so that the token diagonally of e mold and t op ubtwo dimensions of the mold opening may be Stantially 011 the line of Fig- 3.

made equal if desired and the hot top may then In the drawing, N1 p es nts a mold stool be square or round, which of course is ideal from pon which is s pp a big end wn mold t standpoint of a minimum urfa of radia- H. In the illustrated case the mold is a slab tion in proportion to the volume of metal hot mold having two wide sides It and two narrow topped. sides l3. All four sides taper somewhat toward Bottleneck molds, so called, are used extenthe top of the mold in order to provide the necessively in the making of rimmed steel, without sary draft.

hot tops, but there they have very special func- The upper end of the mold is constricted by tions, that is to say the constricted opening is two shoulders or necked-in portions l4 which convenient in that it limits the size of the cap extend inwardly from the upper ends of the for sealing the opening, and also the rounded narrow side walls l3. These necked-in. portions may be relatively thin as compared with the walls 12 and I3. Curved surfaces I! of relatively long radii join the inner surfaces oi. these shoulders with the inner surfaces of the narrow side walls of the mold. These shoulders extend inwardly far enough to form a constricted opening 16 with a dimension parallel to the wide sides of the mold which may be substantially the same as the distance between the narrow sides. In such case the opening I6 is substantially square. It may be of a shape other than square, but it should be symmetrical and its horizontal dimensions parallel to the sides of the mold are preferably equal. The area of the mold just below the shoulders is indicated by broken lines at H in Fig. 3. In the event that a floating hot top is to be used the mold should have a neck 9.

When an ingot is to be poured I mount a hot top upon the mold in operative relation with the taken up by flexible sheet metal wiper strips,

not shown, which are well-known in the art. The

- metal casing 20 is provided with an upper semipermanent refractory lining 2| having heat insulating quahties, and the lower end of the easing is protected by a refractory bottom ring 22.

The" ingot body is marked 25 in the drawing and the sinkhead 26 is shown with its shrinkage cavity 21.

The shrinkage cavity tending to form in the ingot body during solidification is concentrated near the vertical center line of the ingot. Hot topping the central part of the mold only therefore fulfills the requirement insofar as supplying feed metal is concerned. The fact that the hot top as herein illustrated has substantially equal horizontal dimensions at right angles to each other is advantageous in that for a given volume of hot topped metal the wall surface and top area exposed to cooling is of minimum extent. Consequently there is minimum loss from solidification of metal in the hot top.

The constriction at the top of the mold provides the means of forming an ingot with an upper end contour similar to that contour of the butt end of a big end up mold, which has been found in practice to be advantageous for rolling in respect to minimizing the amount of loss from cropping.

Although the invention is herein illustrated as applied to a slab mold, it should be understood that in its broader aspects it is equally applicable to molds of any cross-sectional proportions, and that the necking-in of the mold may be effected from all four sides rather than from two sides as herein shown.

Having thus described my invention, I claim:

1. In combination, a big end down slab ingot mold having wide sides and narrow sides, the upper end of said mold being nicked-in from said narrow sides and having a central opening of approximately equal dimensions parallel to said wide and narrow sides, and a hot top of approximately equal horizontal dimensions disposed inoperative relation withnsaid opening and extending upwardly therefrom.

2. In combination, a big end down slab ingot mold having wide sides and narrow sides. the

upper end of said mold being necked-in from said narrow sides and having a central substantially square opening, and a substantially square hot top disposed in operative relation with said opening and extending upwardly therefrom 3. In combination, a big and down slab ii got mold having wide sides and narrow sides, the upper end of said mold being necked-in from said narrow sides and having a central opening of cross-sectional dimensions approximatel the same as the internal width of the mold adjacent the opening, and a hot top of approximately equal horizontal dimensions disposed in operative .relation with said opening and extending uptending inwardly from said narrow sides, the

internal surfaces of said shoulders being well rounded, the upper end of the mold having an opening between said shoulders of approximately equal dimensions parallel to said wide and narrow sides, and a hot top of approximately equal horizontal dimensions disposed in operative relation with said openin and extending upwardly therefrom.

6. In combination, a big end down slab ingot mold having wide sides and narrow sides, the upper end of said mold having shoulders extending inwardly from said narrow sides, the internal surfaces of said shoulders being well rounded, the upper end of the mold having an opening between said shoulders of approximately equal dimensions parallel to said wide and narrow sides, and a. hot top of the full floating type of approximately equal horizontal dimensions extending into said opening.

WALTER W. URMETZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 385,836 Boucher July 10, 1888 644,740 Grifiith Mar. 6, 1900 1,055,833 Talbot Mar. 11, 1913 1,417,246 Hazeltine May 23, 1922 1,603,662 Coates Oct. 19, 1926 1,720,857 Perry July 16, 1929 1,804,206 Charman May 5, 1931 2,190,392 Beldin Feb. 13, 1940 OTHER REFERENCES The Making, Shaping and Treating of Steel, page 652, pub. by Carnegie-Illinois Steel Corp., Pittsburgh, copyright 1940.

Gathmarn: "The Ingot Phase of Steel Production, pages 18 and 19. Copyrighted in 1942.

- Printed by Schneidereith 8; Sons, Baltimore, Md.

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