US1687799A - Casting ferrous metals - Google Patents

Description

, No Drawing."

Patented Oct. 16, 1928.

UNITED'STATES PVATENT'QFFICE.

YORTER W. SHIMEB' ANIJEDWAED B. SHIMER, OF EASTON, PENHSYLVANIA.,

oes'rmo FERROUS METALS.

This invention relates to the casting of ferrous metals, and particularly to a method of treating chaolets used in the making of v iron or steel castings wherebya leak-proof union .is made between the chaplet and the cast metal.

In making metal casting in molds having cores, studs, anchors or so-called chaplets are employed to support the cores and hold them in position during the casting operation, which chaplets are of necessity incorporated within and gral part of the fin shed iron founding chaplets of'cast casting. In iron have ,been used but thesev are often melted by the formation of a surface'film of oxide, and the result is that although the chaplets are em-' bedded in the finished casting, they are not integrally united with it and the casting is therefore not leak-proof. In an attempt to overcome this difficulty it is the'present practice to coat the chaplets with tin, and the use of copper and silver for this purpose has also been proposed. Although chaplets thus treated are better than untreated ones, the use of such coatings has not solved the prob lem and imperfect castings very frequently result when chaplets coated with these metals are used. Tin, copper and silver are not metals that have been found to have any use-' ful effect when added to cast iron or steel. Silver in addition is too expensive for general commercial use, and tin, the metal most commonly used to coat chaplets, frequently zauses the formation of a spongy zone around the chaplet, and castings in the making of which tin-coated chaplets have been used, often fail to be leak-proof.

- In accordance with the present invention we have provided a novel coating for chaplets which is relatively free from the objections noted above. Chaplets so coated become integrally united with the iron or steel cast about them and the resultant castings are substantially leak-proof. In attaining this result we coat the chaplets with metals or alloys which are commonly found in'iron and steel and which readily alloy with iron and steel at the castingtemperature, particularly the brittle ferro-alloys such as are used should form an inte' mesh sieve.

Such chaplets, how- Application filed August 7, 1925. Serial no. 488 74.

in steel manufacture, The alloys We use meltbelow the temperature of the molten metal being-cast and alloy easily and neturally with the chaplet and the cast metal,

thus completely protecting the'chaplet from oxidation and causing to be united with: the metal surrounding itto form an integral union and a sound casting.

As an example of one method of carrying I out; our invention the following'is given:

Equal parts by weight of spiegeleisen and ferro-phosphorus (for example,-'-spiegeleisen of 20% manganese and: ferro-phosphorus of 17 %-19% phosphorus) are fused together, cooled and crushed to pass a twenty first immersed preferably in a solutiorwof boric acid, in wood alcohol, or other cheap equivalent'and then rolled in. a-mi-xture of 100 parts of the alloy powder with 75 parts The chaplet to be coated is of. finely powdered boric acid orv its equiva lent. The function of the boric acid is to dissolve and flux out rust and metallic oxides, under heat, and thus furnish a clean metallic surfacefor the alloy to fuse against. Instead of usingan alcohol solution of boric acid for wetting the chaplets we have also used successfully waterfoil, kerosene, etc.

chaplets, are then heated The chaplet, or quickly, in any suitable furnace with a minimum of oxidation (the atmosphere of the furnace should preferably be neutral or I slightly reducing) to the temperature of fusion of the alloy, and then quenched in water. The chaplet now has a is alloyed with and is, an integral part offit. The chaplet is ready for use. The elements of the coating, namely iron, manganese, phosphorus, carbon silicon and sulphur are those present in all iron and steel, but exist in the. coating in proportions which make it fusible at a temperature below thatof dull iron, producing a natural union of the coated'chaplet with the iron of the casting in which it is embedded. Moreover, manganese and phosphorus are well known and extensively used deoxidizin'g elements, and thus prevent the formation of the often extremely thin film of oxide between the chaplet and the surrounding metal, which oxicoating which dized parting is the main cause of chaplet v trouble. As a result of these things a far higher percentage of sound castings is made when using our chaplets than when using the chaplets now commonly employed.

Instead of using an ordinary furnace, for

alloy to adhere to the Chaplets by use of oil or some equivalentvehicle and then heat them to the temperature required in a casehardening furnace, the chuplets being packed in boxes surrounded by carhurizing compound as in ordinary case-har-ilening In certain cases it might be advantageous to use an alloy having; a still lower melting point and for this purpose phosphor-mengm nese, phosphor-copper, iferro-sulplnu tin, arsenieand other metals or alloys may be added.

l/Vhen our chaplets are stored for a long time before using; or where they are subjected to condit;v 11s favoring rusting, We protect their surfaces in almost any of the methods commonly used.

We claim 1. A. ehaolet for use in ferrous metal founding, having" a coating of a. ferro- Which melts at or below the casting temperature.

2. A Chaplet for use in ferrous meta] founding, having a coating; of an alloy con taining iron and manganese which melts at or below the castingtemperature.

3. A chaplet for use in ferrous metal founding, having a. coating of an alloy contaming iron, manganese and phosphorus which melts at or below the casting ternperature. A chaplet for use in ferrous metal hmnding, having; a coatingof anielloy made by melting a mixture of spiegel'eisen and lerro-phosphorus in substantially equal parts.

The method of preparing a, chaplet for use, which comprises applying to the Chaplet :1 term-alloy in pulverulent form, and a fluX, and l'ientii'ig to melt the alloy to form a coating on the cheplet.

6. The method of preparing; a steel chaplet for use; which comprises wett ng the Chaplet,

' pulyerulent m1 ure oi terroaphoius spieg'eleisen' and a flux, and hosting to melt the mixture and form a ter oal 13/ coating; on the chaplet.

7. A chaplet for use in ferrous metal ounding, having a coating of an alloy containing 21 deoxidizing element which alloy melts at or below the casting temperature.

.nding having a coating ofan alloy contaming iron and a deoxidizi'ng element which "lnQll'S at or below t 1e casting temperature.

In testimony whereof we hereunto afiix our signatures.

"PORTER W. SHIMER.

EDVARD- B. SHIMER.

cheplet for use in ferrous metal