US1560036A - Method and apparatus for casting ingots - Google Patents

Description

Nov; 3, 1925. 1,560,036

- w. P. BROWN METHOD AND APPARATUS FOR CASTING INGOTS Filed March 25. 1922 2 Sheets-Shae! 1 I fiz HIL .nHIHHHHHII- Nov. 3, 1925.

v w. P. BROWN METHOD AND APPARATUS FOR CASTING INGOTS I Filed Mar'ch 25. 1922 2 Sheets-Sheet 2 -----E::::I'Iii**i11---- HHh nu -f HIH HHH vertica Patented Nov. 3, 19258 UNITED PATEN'E' OZFHQEZ.

WILLIAM POWELL BROWN, OF BLACK LICK, PENNSYLVANIA, ASSIGNOR T0 VALLEY MOULD & IRON CORPORATION, OF SHARPSVIL E, Z ENNSYLVANIA, A CORPORA- TION OF NEW YORK.

METHOD AND APPARATUS FOR CASTING- INGOTS.

Application filed. March 25, 1922.

To all whom it may concern.

:Be it known that I, l/VILLIAM P. BROWN, a citizen of Canada, residing at Black Lick, in thecounty of Indiana, State of Pennsylvania, have invented certain new and useful Improvements in Methods and Apparatus for Casting Ingots, of which the following is a specification.

This invention relates broadly to metallurgy and more specially to the method and apparatus for casting steel ingots.

Hcretofore in the art the most customary way of pouring vertical ingots is that of pouring the ingot into the open mouth of a l mold and permitting the molten steel to rise upwardly in the mold against the stream pouring intothc mold. it has also been the practice in connection with vertical pouring to maintain the upper portion of the mold hot by conserving heat in the steel to cause the upper portion of the ingot to remain liquid as long as possible so that any pipes formed due to shrinkage would be filled by liquid which would flow into the pipe "due to gravity. It is not unusual to cap vertical. molds when the steel is wild but such cap is more specially for the purpose of preventing the steel from splashing out of the mold than it is for the purpose of determining the character of the ingot or of shaping the end of the ingot. In vertically poured ingots, in substantially all. cases the ingot cools first at the bottom of the mold and thus the lighter segregated materials are driven upwardly into that portion of the steel which is kept hot at the top of the mold. The result is an ingot wherein the constituents of steel is non-uniform throughout the ingot due to segregation. Furthermore as the ingot cools the steel contracts and in the majority of cases in such vertirally poured ingots pipes are formed.

The present invention overcomes the difficulties of the known art by providing a vertical mold in which the upper end is substantially closed with the exception of an opening suflicient to permit the escape of gases and to provide a reservoir to hold a supply of steel to fill up cavities which may tend to form and thus prevent what is known in the art as secondary pipes. In the present invention the upper end of the mold Serial No. 546,649.

is provided with a relatively large heat ab- 7 sorbing capacity andthe upper end of the ingot is adapted to be chilled at the highest rate. with the chilling action progressing downwardly from the top toward the base of the mold. This direction of chilling prevents segregation because segregated materials are frozen out of the solidifying or crystallized steel and tend to rise upwardly beneath the ceiling of the solidifying or crystallizing steel which ceiling is progressing downwardly and overtakes and encloses the materials which tend to be expelled during the freezing operation. In carrying out the present invention it is preferred that the entire surface of the matrix of the mold shall be a chill surface so that a chilled shell is formed which encloses any gases that tend to escape other than such gases as may escape through the riser opening before the riser freezes. In View of the fact that the riser opening chills quickly it will appear that gases in the steel are enclosed in a steel shell which contracts and prevents the ooeluded gases from becoming free gas so that the ingot freezes into a substantially solid mass. Preferably the present invention is carried out by bottom pouring. A suitable runner is provided with a vertical column and conduits leading into the bottom of the vertical mold matrix so that the moltenter of the ingot in a zone which gradually extends upwardly and outwardly to the surface of the rising steel. As the upper portion of the ingot cools the metal in the riser is drawn back or flows back into the ingot thereby preventing a secondary pipe in the upper portion thereof and as the heat is being absorbed. from the ingot around the riser opening the steel in this opening solidifies before the central mass of the ingot is chilled. The feeder runner continues to supply molten steel to the interior of the ingot thereby preventing the primary pipe forming adjacent the inlet opening. As the chilled steel shell around the ingot continues to cool it tendsto contract thereby subjecting the interior of the ingot to pressure so that very little free gas is released and consequently the entire ingot is substantially a solid mass of steel.

Having generally described the present invention it may be stated that the objects of the invention are as follows:

The principal object is the method of forming vertical ingots of steel which method comprises providing a vertically extending mass of molten steel in the shape of the ingot desired, and chilling the mass adjacent the upper end thereofso that the chilling effect progresses downwardly toward the bottom of the mass when the mass is being frozen.--

Another object of the present invention is the method of pouring vertical ingots which comprises pouring the ingot from the bottom through a. vertical runner and chilling the ingot in a direction opposite to that of the movement of the oncoming steel.

A still further object of the present invention is an ingot mold comprising a vertic'al mold having a substantially closed upper end and being adapted to be filled from the bottom from a vertical runner and with the upper end of the mold comprising a chill member. I

Another object of the present invention is a vertical. mold provided with a chill cover having a gas outlet therein and being adapted to be filled by a runner adjacent the bottom thereof.

Another object of the present invention is a vertical mold with the top thereof substantially closed and with said top comprising a curved chill surface shaped so that lines at right angles thereto will intersect the axis of the mold and with the mold having a relatively large heat absorbing capacity adjacent said curved surface.

Other and further objects of the present invention will in part be obvious and will in partbe pointed out hereinafter in the specification or by reference to the accompanying drawings in which like parts are represented by like characters throughout the several figures thereof.

It is realized that the present invention may be carried out by methods slightly ditterent than those herein specifically described and in structures other than those specifically shown in the drawings so therefore it is desired that the disclosure herewith shall be considered as illustrative and not in the limiting sense.

Figure 1 is a vertical elevation of one form of mold embodying the present invention and showing the top of the mold solid.

Figure 2 isa difierent embodiment of the invention andillustrating. the top of the mold formed of a cnepiece cap.

Figure 3 is another diiierent embodiment of the mold showing the top formed of a two piece cap which is split substantially in the middle.

Figure l illustrates a split mold for carrying out the present invention.

Figure 5 is a side view of the mold illus trated in Figure t and illustrating a runner column.

Figure (5 is a split mold with the runner brick in the sprue plate.

Figure 7 illustrates a split mold having a solid bottom and shows merely the bottom portion of the mold.

In the mold illustrated in Figure l the moldbody 1 is shown as being substantially rectangular in outside dimensions with the bottom of the mold open and the side walls 9 adjacent the bottom as at. 2 being relatively thin. The matrix portion at of the mold tapers upwardly and preferably the top thereof as at 5 is curved into substantial portions of the spherical surface. top at the upper part is much thicker than at the lower part and thereby provides greater heat absorbing capacity. This is particularly true around the top wherein large masses of metal 6 are provided. The topmost portion of the matrix leads into a vent opening 7 in which molten steel is adapted to rise when the mold is filled. The mold; is provided with handling staples 8 so that stripping or other purposes. The mold is adapted to set upon a floor plate or s-prue plate 9 in which a suitable runner tile 10 is adapted to be set. This runner tile 10 is constructed to be connected with a runner column so that molten steel may be introduced into the matrix a at substantially the bottom thereof.

In Figure 2 the top of the mold is illus tratcd as being formed of a cap 11 which is provided with locking lugs 12 that are adapted to fit corresponding locking mcm bers l-l at the body portion, otherwise the mold is similar to that illustrated in Figure 1.

Figure 3 illustrates a mold similar to that shown in Figure 2' with the exception that the top is formed of two pieces 15 and 16 which are splitacross the opening 7 so that when the top pieces 15 and 16 are removed the root which may be lc-t't in the opening 7 is free from the mold.

Figures 4- and 5 illustrate the invention embodied in a split mold wherein the mold bod is formed of two pieces 17 and 18 which pieces are complementary and are adapted to be held together by C clamps l9 -which may be driven over suitable lugs 20 thereby locking the parts together. In this type of mold the bottom of the matrix 4 is illustrated as being closed and the runner tile 21 is atla-ptedt'o be supportedby the side walls of the mold as shown in Figure 5. The run- The mold.

it may be conveniently lifted for till ner tile 21 is preferably connected with the runner column 22 which extends at least as high as the mold and preferably parallel thereto, which runner tile is capped by a suitable funnel or fountain 24: into which molten steel is adapted to be poured;

Figure 6 illustrates a mold similar to that shown in Figures and 5 with the exception that the runner tile 21 is in the sprue plate 9 and is supported thereby.

Figure 7 illustrates another embodiment of the split mold in which the bottom of the mold is closed and the short runner tile 25 connected with the runner tile 21 which run ner tile is in the sprue'plate 9 and the base of the mold is closed.

From the above description and disclosure in drawings it will appear that the present invention contemplates pouring vertical ingots from the bottom and chilling the upper part of the vertical ingot before fresh steel coming into the bottom of the mold has been chilled. It will be noted that the sup ply of steel comes in from the bottom of the mold and flows upwardly towards the top so that there is a column of hot steel extending through the ingot from the top to the bottom and that when the hot steel strikes the chill top the upper part of the mass freezes so that it does not continue to rise. There fore the oncoming steel in the bottom of the mold will be steel which is freshest from the ladle and it will carry the highest temperaure of any steel in the mold. Chilling will then progress from the upper end of the mold toward the runner which continues to supply hot steel through the runner tile so long as hot steel is needed to feed the ingot. This method of chilling the ingot in the op posite direction from the oncoming of the melted steel produces conditions wherein a substantially solid ingot is the result.

Having thus described my inventiomwhat ii claim is:

1.. The method of casting steel ingots or' the like which comprises forming a mass of molten steel into the shape of an ingot with the major axis thereof substantially vertical; chilling substantially the entire exterior of the ingot to form a frozen steel shell around the mass, and causing the chilling to progress downwardly and iinvardly with the progress in the donunwird direction being at :1 higher rate than the progress in the inward direction.

The method of asting steel ingots or like which comprises forming a mass of molten steel into the shape of an ingot with the major axis thereof substantially vertical by causing the steel to flow upwardly within a confined space; chilling substantially the en tire exterior of the ingot to form a frozen steel shell around the mass, and causing the chilling to progress downwardly and inwardly with the progress in the downward direction being at a higher rate than the progress in the inward direction.

3. The method of casting steel ingots and the like which comprises forming a mass of molten steel in a suitable chill mold into the form of ingot desired and with the major axis of the mass being substantially vertically disposed; supplying the molten steel to the bottom of the mass while forming the ingot, and chilling the top and the upper portion of the mass quickly to cause the freezing of the steel to progress rapidly in a downward direction.

4. The method of casting steel ingots and the like which comprises forming a mass of molten steel in a suitable chill mold into the form of ingot desired and with the major axis of the mass being substantially vertically disposed; supplying the molten steel to the bottom of the mass while forming the steel to progress rapidly in a downward direction.

The method of casting steel ingots and the like which comprises forming a mass of molten steel in a suitable chill mold into the form of ingot desired and with the major axis of the mass being substantially vertically disposed; supplying the molten steel to the center of the bottom of the mass while forming the ingot and chilling the top and the upper portion of the mass quickly when the mold is filled to cause the freezing of the steel to progress rapidly in a downward direction.

6. The method of casting steel ingots or the like which comprises supplying molten steel at the bottom of the matrix of a vertical chill mold to fill the mold, and chilling the top end of the ingot to cause the heat gradient to run from the top of the ingot toward the bottom thereof.

7. The method of casting steel ingots or the like which comprises supplying molten steel at the center of the bottom of the 1natrix of a vertical chill mold to fill the mold, and chilling the top end of the ingot to cause the heat gradient to run from the top of the ingot toward the bottom thereof.

8. The method. of casting steel ingots or the like which comprises supplying molten steel at the bottom of the matrix of a vertical chill mold to fill the mold, chilling the ingot to cause the heat gradient to run from the top of the ingot toward the bottom there of and causing a riser of molten steel to extend above the matrix portion of the mold after the mold is filled for supplying molten steel to the top of the ingot when the chilling operation of the whole ingot begins.

9. chill mold for casting vertical steel ingots or the like comprisinga body portion with the heat absorbing capacity of the mold walls increasing materially from the bottom of the walls toward the top thereof, and means to introduce molten steel into the bottom of the mold matrix to cause the hot steel to rise toward the toprof the mold.

10. A chill mold for casting vertical steel ingots or the like comprising a body portion with the heat al'isorbing capacity of the mold walls increasing from the bottom of the walls toward the top thereof, with the top end of the mold covered by large capacity heat absorbing means, means to introduce molten steel into the bottom of the mold matrix to cause the hot steel to rise toward the top of the mold, and a gas vent in the top of themold to comprise a gas outlet and a supply of steel to prevent secondary pip- 111g.

11. A chill mold for the casting of steel ingots and the like, said mold comprising a body portion with the matrix thereof having a substantially vertical axis, a closed top for said mold and having a heat absorbing capacity which is greater than the side walls of the mold, and means to introduce molten steel into the bottom of said matrix.

12. A chill mold for the casting of steel ingots and the like, said mold comprising a body portion with the matrix thereof having suhst'intiallya vertical axis, a closed top f 1' said mold with the matrix wall thereof being curved and havii'ig a heat absorbing capacity which is greater than the side walls of the mold, means to introduce molten steel into the bottom of said matrix, and a gas outlet in the center of said closed top.

15. An ingot mold for casting steel ingots and the like conmrising a body portion 01 chill metal having a substantially vertical matrix with the exterior of the mold being substantially rectangular and with the matrix walls inclined inwardly toward the top and with the thickest metal in the mold be ing over the top of the matrix whereby the heat absorbing capacity of said walls is increased toward the top of the mold, and means to introduce molten steel into the mold.

l t. A mold for the casting of steel ingots and the like said mold comprising a body portion of (hill metal having a substantially vertical matrix therein, conduits to supply molten steel to the bottom of said matrix, and means associated with the body portion to absorb the heat from the molten steel when the matrix is fill-ed in such manner as to cause the heat gradient to run from the top of the mold toward the bottom thereof.

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