US2138121A

US2138121A - Ingot mold

Info

Publication number: US2138121A
Application number: US96733A
Authority: US
Inventors: Ramsey George
Original assignee: Valley Mould & Iron Corp
Current assignee: Valley Mould & Iron Corp
Priority date: 1936-08-19
Filing date: 1936-08-19
Publication date: 1938-11-29
Anticipated expiration: 1955-11-29

Description

G. RAMSEY INGOT MOLD Nov. 29,y 1938.

4 Sheets-Sheet 4 Filed Aug. 19, 1956 frr Il? /I/M ATTORNEYS Patented Nov. 29, 1938 INGOT MOLD George Ramsey, Brooklyn, N. Y., assignor to Valley Mould & Iron Corporation, Hubbard, Ohio, a corporation of New York Application August 19,

' 5 claims.

The present invention relates to metallurgy and more especially to ingot molds.

One of the problems in connection with ingots, and more especially steel ingots, is the provision of suitable shapes for the portion of an ingot cast in the bottom of an ingot mold. The molten metal in this part of the ingot freezes first and usually more rapidly than in lthe other portions of the mold. This is particularly true with bigend-up molds used in the steel industry since the weight of the steel forces the ingot tightly against the bottom of the mold where the largest mass of mold metalis present, thereby rapidly conducting away the heat from the lower end of molds. In the big-end-up molds, the invention e the mold may be rolled without seriously disturbing the crystalline structure. The shape of the is preferably embodied in the mold itself, whereas in big-end-down molds, the invention is preferably embodied in the stool.

The present invention in the preferred forml may be embodied in corrugations arranged in the bottom of the mold and of such form as to provide asuri'ace which obviates a defect lcnown in the art as pyramiding so that the end of mold matrix is such, due to the corrugations, that the crystals in the ingot do not take a single dennlte axis. and consequently, the varied directions of the crystals present a stronger structure against rolling strains. ,y

yThe corrugations in the bottom of the mold are preferably in a horizontal plane or planes, and where the side walls are corrugated or rippled, these corrugations in the side 'of the mold matrix are in verticaleplanes. bottom of the mold matrix may be arranged with reference to corrugations in the sides of the mold matrix `in such manner asto cause a blending of the curves where the side corrugations meet the' bottom eorrugations. This feature is valuable both as to the life of the mold and as' to .desirable structure of the ingot.

Other and further objects of the ,present in- The corrugations in the 1936, Serial No. 96,733

(Cl. 'I5-139) vention ,will in part be obvious and will in part be pointed out hereinaftergby reference to the accompanying drawings forming a part of this application.

Fig. 1 illustrates a section of the bottom portion of a big-end-up mold provided with the present invention and wherein the mold has smooth side walls.` I

Fig. 2 is a cross-section on line 2-2 of Fig. 1.-

Fig. 3 illustrates a section of the bottom portion of a big-end-up ingot mold with side walls slightly corrugated and with the bottom of the matrix comprising the frustum of an inverted pyramid.

Fig. 4 is a section 'on line 4--4 of Fig. 3.

Fig. 5 illustrates a section of the bottom portion of a big-end-up mold with the side walls corrugated and with the side wall corrugations blending into the corrugationsin the bottom of the mold. The bottom corrugations are imposed upon curved surfaces.

Fig. 6 isa section on line 6--6 of Fig. 5.

Fig. 7 illustrates a section of a portion of a l l big-end-down mold on a stool showing'the botL tom corrugations in the stool.

Fig. 8 is a plan view of the stool shown in Fig. '7. Figs. 1 to 6 inclusive disclose the present invention as being embodied in a type of mold usually referred toas a closed bottom mold. These molds are alsovofjthe big-end-up type. Such molds usually have a major vertical matrix A" and a minor matrix B comprising the bottom of the moldand inwhich the lower end of the ingot is cast. v

Figs. 'Tand 8 disclose atype of mold having a major vertical matrix C formed in the mold itself and a minor bottom matrix D formed in the stool on which the open bottom mold sets. Big-end- Y downmolds are of `t-his type and the mold separates vfrom the stool when the ingot is stripped from the mold.

The control of the'crystallization of steel in the. lower end of an ingot formed in the minor bottom matrix portion of the mold is a serious problem in the steel art. Where the crystallization in this portion 'of the ingot is bad, it may extend upwardly into `the bodyof the ingot to such an extent as to require deep cropping with an attendant seriousu economic loss. Sometimes in bad cases of improper crystallization in the lower end l of an ingot, this portion of the ingot will completely separate from the body of the ingot during the rolling process. 'I'his is due to weak cleavage planes formed by the meeting or intersection of crystals growing from angularly disposed chill surfaces. Steel crystals grow at right angles to -chill surfaces and where the ends of these crystals meet at a sharp angle, a weakened cleavage plane occurs. In the present invention, the wavy surface of the minor matrix in the bottom of a mold prevents the crystals in the bottom of the ingot from growing to such an extent as/to impinge against the ends of crystals growing from the side walls of the major matrix of the mold. This breaking up of the direction of growth of these crystals in th minor bottom matrix of the mold causes ingots which are cast in the mold to have a crystalline structure in the lower end thereof of such character that the steel in the lower endV of the ingot is of the same quality as steel in the body of the ingot. l

Figs. 1 and 2 of the drawings illustrate a vertical section through the lower portion of a bigend-up ingot mold having plane side walls I on the matrix of the mold. 'I'hese side walls I, at

the bottom of the matrix., curve at 2 to blend intor a corrugation 4 in the bottom of the mold. Another corrugation 5 is provided around the plug opening 6. 'I'his plug opening 6 is adapted to be closed by a suitable plug as is well known in the art.

In the construction shown in Figs. 1 and 2, the Y radii 'I for the corrugations is preferably less than one-half of the minimum cross-section of the ingot and the angular extent of each curve is preferably substantiallyY 45. This produces a construction in which relatively low corrugations are formed so that the tendency of cleavage lines or planes, due to focusing of dendritic crystals,

'comprise a strong juncture between the side wall surfaces and bottom surfaces of the ingot. The axes I of the radii forming the bottom corrugations are shown as being arranged in substantially straight planes so that the corrugations II inthe structure shown in Figs. 3 and 4 are superimposed upon surfaces comprising the frustum of an inverted pyramid. 'I'he structure embodied in Figs. 3 and 4 is well adapted for a rippled or waved sided mold matrix.

The structure shown in Figs. and 6 discloses a corrugated mold in which the corrugations I2 are superimposed upon a substantially flat sided matrix and the crests I4 of these corrugations on the side walls merge with the tangent I5 of the corrugation I6. The axes I'I of the corrugations I8 lie in curved lines I9 and 20. In the construction illustrated in Figs. 5 and 6, the bottom .of the I ingot' is rounded and the side corrugations I2 blend into the bottom corrugations at a somewhat deeper position than do the side corrugations 8 illustrated in Figs. 3 and 4. f

Figs. 7 and 8 illustrate a mold construction in which the bottom portion of the ingot is formed by a cup 2| in a stool 2'2. The matrix of the mold 24 is illustrated as being substantially circular in contour with vertically extending corrugations 25 in the side wall thereof and with the cup 2I being provided with a central cup area 26 and concentric corrugations 21 surrounding the cup area. The type of structure illustrated in Figs. 7 and 8 is particularly adapted for the casting of cylindrical or other shaped ingots in which the bottom of the ingot is cast against a stool. In the mold shown in Figs. 7 and 8, there is a controlled crystallization in the bottom of the ingot of such character as to prevent undesirable characteristics extending from the bottom of the ingot into the lower portion of the body of the ingot.

The term corrugations as used herein isintended as a broad term to include structures having salient hand non-salient elements whether they be in the form of utes, flats, curves, or other shapes known in the art, for increasing surface area on the matrix of the mold.

What I claim is:

1. In an ingot mold construction, a vertical major mold matrix terminating in a minor bottom matrix, and a plurality of corrugations in said minor bottom matrix, said corrugations extending in substantially a horizontal direction, the radii of the salient portions of the corrugations being substantially the same length as the radii of the non-salient portions of the corrugations.

2. In an ingot mold construction, a major vertical matrix portion and a minor bottom matrix portion extending downward beyond said major vertical matrix portion, vertical corrugations in the side walls of the major Vertical matrix portion, and a plurality of horizontal corrugations of substantially uniform height and width in said minor bottom matrix portion to produce a wavy surface on said bottom matrix portion.

3. In an ingot mold, a major vertical matrix portion and a 'bottom portion extending downward beyond lsaid major portion, a wavy surface on saidbottom portion comprising a plurality of substantially uniform corrugations to increase the surface area thereof and to vary the direction of crystal'formations to produce a strong crystalline structure at the lower end of an ingot cast in said mold, the crests of said waves being in planes substantially at right angles to the axisV of said vertical matrix.

4. In aningot mold, a vertical matrix portion, a bottom portion extending beyond the vertical matrix portion, vertical corrugations in the side walls of the vertical matrix portion, and a plural-` ity of horizontal corrugations in the bottom portion, the length of curves of said horizontal corrugations extending substantially 45 of an arc,

for both the salient and non-salient portions of said corrugations. p

5. In an ingot mold, a vertical major matrix portion, a bottom minor matrix `portion extending beyond the vertical major portion, and a plurality of horizontal corrugations in the bottom minor matrix portion, the lengthof curves of said horizontal corrugations extending substantially 45 of an arc for both the salient and non-salient portions of said corrugations.

GEORGE RAMSEY.