US1151398A - Mold for producing composite metal castings. - Google Patents

Description

A. ROJEKOFF. MOLD FOR PRODUCING COMPOSITE METAL CASTINGS. APPLICATION FILED'JULY 24. 1914 1,151,398.. Patented Aug. 24,1915.

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ALEXANDER ROJEKGFF, OF BIEJITZA, RUSSIA.

MOLD FOR PRODUCING COMPOSITE METAL CASTINGS.

Original application filed September 18, 191.2,Seria1 No. 720,953; Divided Specification of Letters Patent.

Patented Aug. 24, 1915.

19114. Serial No. 852,818.

To all whom it may concern:

Be it known that I, ALEXANDER RoJnKorr, a subject of the Emperor of Russia, residing at Biejitza, Russia, have invented certain new and useful Improvements in Molds for Producing Composite Metal Castings, of which the following is a specification.

My invention relates to steel castings composed of a plurality of various layers of steel, that is, layers having a different chemical composition, such as described in my application Serial No. 720,953, filed on September 18th, 1912, of which application, this application is a division.

The particular object of this invention is to provide means for producing perfect castings of this kind, made up of a number of concentric layers. By perfect castings, I mean castings which are free from blow holes, cracks or other defects. For making a casting of this kind a mold is used with partitions placed in the mold of polygonal or circular cross section. In order to produce a successful casting, these partitions must be split so that upon coming in contact with the hot fluid metal, they can expand without subjecting the casting, as it is allowed to cool, to undue strains, whereby cracks would be formed in the casting and the casting would be spoiled.

In the accompanying drawing, I have shown a mold in plan view with two partitions placed therein to illustrate my invention.

In the construction of the mold shownin the drawing by way of example, the mold proper is designated by the numeral 1, and. is provided with the trunnions 2 and 3 arranged at opposite sides of the mold. In

the mold are placed two partitions 4, 5, the former partition being of polygonal and the partition 5 being of circular cross section. The partition 4 is split at at and the partition 5 at 5, in such a way that the free edges of each partition overlap, a small space being left between these edges. Thus, three compartments are formed by these partitions, A. B. and 0., and by means of such a 'mold a composite casting can be produced,- made up of three layers, each layer having a different chemical composition.

The partitions are made of such a thickness, as to prevent the'molten liquid mass of steel, poured into one of the compart ments, from mingling with the molten liquid mass poured into the adjacent compartment. The thickness of the partitions must be determined by the temperature of the molten steel, as well as by the cross section of the casting to be produced. If the partitions did not have the required thickness, the liquid molten steel of one compartment would melt the partition and mingle with the molten mass in the adjacent compartment, whereas, if the thickness of the partitions were too great, the partitions would not, as they should, properly combine with the molten liquid steel, in which case, of course, the casting would not be a uniformly fused mass. I find that in order to make a perfect casting of this kind, the partitions should have a thickness of no less than 1% and no more than 3.8% of the cross section of the entire casting.

Due to the fact that the partitions are split and a space is left "between the overlapping free edges, the partitions on coming in contact with the hot liquid steel can freely expand, without subjecting the layers, during the cooling period, to undue strains.

It is a matter of great importance that the partitions should completely combine with the molten liquid steel of each compartment and in order to prevent the free edges of the partitions from projecting beyond the individual castings, the thickness of the par titions along these edges is preferably reduced, as clearly shown in the drawing. vVith the partitions thus arranged and shaped, they can, not only freely expand, due to the heat of the molten liquid metal, but they also can uniformly combine with the molten metal and thus a perfect casting, made up of various layers of steel having different chemical compositions, is produced.

The molten masses of steel preferably enter the various compartments from the bottom of. the mold as is well known in the making of castings.

While I have shown in the drawing a mold with two partitions of different cross sections, I wish it to be distinctly understood that my invention isnot limited, of course, to any particular number of partitions, nor to a particular cross section and I use the term polygonal in a broad sense to also include partitions of circular cross overlapping each other, and being free to section,

I claim: In testimony whereof I have affixed my In a mold for producing composite metal signature in presence of two witnesses. .5 castings made up of layers having difierent ALEXANDER ROJEKOFF.

chemical compositions, the combination with Witnesses: the mold of a number of split metal parti- ALEXANDER TSC-HENALOFF, tions of polygonal cross section, their edges H, A. Lovmennvn.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

' Washington, D. G.

move relative to each other. 10;

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