US1731676A - Process of die-casting cast iron - Google Patents

Description

Patented Oct. 15, 1929 UNITED STATES PATENT orrlca CHARLES MEIER, F VALPABAISO, INDIANA.

rnocnss or mn-casrme casr 1301:

lo Drawing.

vents theuse of costly machining operations;

that avoids the difficulties hitherto encountered when ordinary grey iron has been castinto permanent steel molds .through the formation of a carbon scale in contact With the mold walls that entirely eliminates such troubles by using a free flowing compositionwhich does not deposit a carbon scale; and that leads the molten metal through a trap passage way to the casting position from beneath instead of from the side as ordinarily, when the casting is done in sand.

In practically carrying out my invention, I may use any. desired cooperating mold parts, cores, etc., which arepermanently shaped in steel: The number of moveable parts required to cast different shaped objects is 28 variable. In some cases fewer parts are required, and in other cases more. The operating mechanism for movin the parts toward each other to'close the mo d and again separate it makes it easy to remove the completed so casting. The movement of these parts 'however is so coordinated-that the action is simultaneous, which is accomplished in any well known manner.

The entrance passage way for the. molten metal takes the form of a trap, the liquid metal being delivered from beneath the casting position. This insures a more homogeneous casting than is'otherwise possible. The sprue, when the object is cooled, is readily broken oil and may be again-remelted, There is suflicient cross sectional area in the entrance assage way inrelation' to the cubical area to e occupied by the finished object, that i a preponderance of pressure exists in the liquid metal found in the entrance passage way which insures a compact and very dense uniformly distributed grain in the finished product.

, As heretofore stated, the outstanding dif- 0 ficulty'has been in attempting toicast grey Application filed June 20, 1925. Serial No. 38,437.

iron in permanent steel molds. An external scale of hard carbon is formed through the engagement of the molten metal with the steel walls of the mold. Such attem ts have been usually made by forcing the me al into the mold under artificial pressure. In my system, extraneous pressure is not used, dependence being placed on gravity and the useof a free flowing liquid that does not form an exterior scale of hard carbon.

In order to eliminate the-formation of car bon scale and produce a free flowing metal, I have found the following composition to give practical results,'th ough of course I do not limit myself to the specific ingredients herein disclosed. As an example of these, I may use an alloy composed of 50% aluminum, 25% nickel and 25% silicon. Of this alloy,

' in a total charge of one hundred pounds, 2%

is mixed with 98% of pig iron. I .do not,

as stated, limit myself to the specific ingredients indicated above, nor to the exact proportion mentioned, because extreme variations in the'composition of the pig iron may require a cooperating modification of the alloy and the extent of its use.

It is of course understood that the metal which is to be used for making (lie castings must obviouslybe first heated. This may be done in any desired manner, since this step is such an ordinary and well known one.

What I claim is:

The process of producing a free flowing non-scaling iron adaptable for use under pressure in steel molds, which consists in mixing about 2% of the following alloy with about 98% of pig iron, such alloy comprising a substantial amount but not less than 50% aluminum, 25% nickel and 25%= silicon.

In testimony whereof 'I afiix my signature.

' CHARLES MEIER.