US772439A - Mold-coating. - Google Patents

Description

UNITED STATES- Patented October 18, 1904,

PATENT ()FFICE.

CHARLES SP. SZEKELY, SR, OF NEW YORK, N. 'Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO -THE METAL CASTING COMPANY OF AMERICA.

MOLD-COATING.

SPECIFICATION forming part of Letters Patent No. 772,439, dated October 18, 1904. Application filed May 13, 1908. Renewed March 16, 1904. Serial No.'198,484. (No specimens.)

To, aZZ whom it may concern:

Be it known that I, CHARLES Sr. SznKnLY, Sr. a subject of the Emperor of Austria-Hungary, residing in the city, county, and State of New York, haveinvented certain Improvements in Mold-Coatings, of which the following is a specification.

It has always been a great desideratumin the casting of metals in metal molds, and particularly in casting iron in such molds, to ob tain a casting without a chilled surfacethat is, to obtain a casting of which the surfaces shall be soft and readily workable with tools; but up to the present time, so far as I am aware, this result has not been attained. It is also a common occurrence to find metallic articles cast in metal molds full of blow-holes or having a certain degree of porosity, due to the included gases.

I have discovered that in orderto successfully cast molten iron or steel in a metal mold and to keep the surfaces of the article cast from chilling and also to obtain a casting of more compact and uniform texture than is usually obtained certain conditions must be fulfilled, namely: First, the surface of the mold which is to come in contact with the molten metal must be coated with a wash spread uniformly over said surface; second, that this coating must be of such a nature that it will adhere to said surface although submitted to the influence of greatly-varying temperatures; third, that the wash employed must leave a thin coating between the surface of the mold and the casting, which coating shall -not act either upon the metal of the mold or the metal of the casting: fourth, that this wash must be composed of an inorganic substance which will produce said inert coating and a mineral vehicle of such consistency and quality as will hold the inorganic substance in suspension; fifth, that this mineral medium shall be inflammable from contact with the molten metal of the casting; sixth, that this mineral vehicle must not, however, be so volatile that its contact with the molten metal will generate gases too rapidly and cause by their generation and ignition explosions that metal of uniform close texture and free from porosity or pitting. The casting may also be readily removed from the mold, as therewill be no adhesions.

For the inert coating-body of the wash, to which. this invention appertains, any inorganic substance may be used which has no chemical action on either the metal of the mold or the metal of the casting and that will not decompose and combine with either under the con-v ditions to which it is exposed in the mold. For the liquid mineral vehicle of said inorganic substance, said vehicle having the inflammable'and gas-producing requisites, theso-called mineral oils or liquids will serve perfectly.

As an example of the wash, I prefer to employ the following: French chalk, in powder, twenty parts; kerosene of over one hundred and fifty flash test, forty parts; paraffin-oil, refined, forty parts. These are mixed thor of certain kinds oughly together, the fluid ingredients holding the chalk in suspension.

7 In carrying out the process of making a casting the inner surfaces of the metal mold are evenly coated with the above compound or wash with the aid of a brush or any other suitable tool or implement, the mold closed, and the molten iron or steel poured in. When the mold is opened, the casting may be readily removed, and when cooled it will be found to be smooth, free from porosity or blow-holes, without chill or surface-hardening, and of uniform compacttexture when its fracture is examined.

The invention is not, of course, limited strictly to the particular ingredients and proportions thereof given in the above example. Their substantial equivalents may be employed.

By iron castings as spoken of in the above steel castings are meant to be included. For my purpose molds of iron are preferred.

I do not herein claim the process of casting nor the product produced thereby, as these are embodied in separate applications.

Having thus described my invention, I claim 1. A Wash for coating the inner surface of a metal mold for making iron and steel castings, composed of an inert, solid inorganic substance, Which will have no chemical action on either the metal of the mold or the metal of the casting, and a vehicle for said inorganic substance, said vehicle being an inflammable mineral liquid and paraflin.

2. A Wash for coating the inner surface of a metal mold for making iron and steel castings, composed of a solid inorganic substance, Which will have no chemical action on either the metal of the mold or the metal of the casting, and a vehicle for said inorganic substance, said vehicle being an inflammable mineral liquid and paraflin.

3. A wash for coating the inner surface of a metal mold for making iron and steel castings, composed of French chalk in powder, and a vehicle for same, said vehicle being an inflammable mineral liquid and parallin.

4. A wash for coating the inner surface of a metal mold, composed of French chalk in powder, kerosene, and parafiin-oil, the latter holding the French chalk in suspension in the liquid vehicle.

In witness whereof I have hereunto signed my name, this 6th day of May, 1903, in the presence of two subscribing witnesses.

CHARLES SP. SZFIKELY, Sn.

\Vitnesses:

PETER A. Ross, H. G. CoNNn'rT.