US1850477A - Producing metallic ingots - Google Patents

Description

March 22, 1932. ROTH 1,850,477

PRODUCING METALLIC INGO'IS Filed April 14. 1931 l ed 2222 02" Patented Mar. 22, 1932 UNITED STATES ERNST ROTH, OF LAUTA'WERK, GERMANY PRODUCING METALLIC INGOT S Application filed April 14, 1931, Serial No.

My invention relates to improvements in the method of making metallic blocks or ingots by casting the liquid metal into moulds, and the chief object of my invention is to produce an ingot of a fine-grain or microstructure and free of pores, blow-holes and piping.

In the manufacture of cast metallic ingots it is very important to control solidification, since not only many advantageous physical properties of the cast metal but also the grain or structure of the same inclusive the removal of pores and piping depend thereupon.

Various methods have-been proposed for the purpose of controlling solidification.

Thus it has been suggested and found advantageous to use moulds made partly of bad and partly of good heat conducting materials or capable of removing heat from the molten metal slowly or rapidly, or to use moulds equipped with chilling or combined chilling and heating arrangements, or to provide a chilling and heating system, through which the moulds are transported, or which is caused to pass along the mould in apredetermined direction. Furthermore moulds are universally known whereof the hollow walls are filled with a metal of a lower melting point, adapted to gradually return the absorbed heat during solidification of the metal.

All of these known methods and moulds, however, cannot be used in practice except when attended by highly skilled founders; but even in such a case the various disadvantages, f. i. the formation of elongated crystals extending more or less laterally in the form of a fan, blow holes, piping and an irregular, coarse structure cannot be fully avoided, because the solidification of the casting during the casting operation cannot be controlled and, therefore, the solidification of the liquid m'etal and the removal of heat therefrom will take place in advance of or with retardation to the correct conditions. Even if the 'founder succeeds in avoiding the hereinbefore stated defects and producing a satisfactory casting, he cannot avoid the lost head or the necessity of a supplemental orfinal adding of metal at the end of the casting operation.

After much study and research I have dis- 530,033, and in Germany March 4, 1931.

covered a new way of making cast ingots, which are absolutely free of all the named defects and endowed with a uniform, finegrained structure throughout and devoid of pores and piping and have no lost head.

Accordingly my invention based upon said discovery mainly comprises the method of strictly separating the casting operation from the solidification, by pouring the metal in a heated mould, preventing solidification along the walls during the casting operation, then turning the filled mould and removing during solidification the heat from one side of the mould only.

I shall now proceed to describe the new method and the new mould, which is shown in the annexed drawing more in detail, for purposes of exemplification, and may be of any desiredshape and size.

The sameis made of a refractory material such as burned fire-clay b, which is a bad or poor conductor of heat, and which is placed in an iron casing a. The cover 0 of the mould is made of copper or any other appropriate material, which is a good heat conductor;a cooling device (1 is provided in the said cover. According to the new method, the mould as above described, is heated prior to the casting operation and when so heated the molten metal is rapidly poured'into the same, so as so to fill the mould short of a small top space between the level of the molten metal and the rim of the mould. This done, the cover 0 is placed upon and firmly attached to the mould, locking means of any suitable or usual con- 55 struction being employed for the latter purpose; the entire mould is now turned rapidly for by means of the pivots e or on a turning machine, or any appropriate manner.

The underlying idea of this method is to 00 prevent the molten metal from solidification at or near the walls of the mould at times, when in the course of the casting operation molten metal is still poured into the mould. For in sucha case solidification cannot set in in auniform manner, but unavoidably must take place in successive layers.

What Iclaim is: T 1. A method of, casting metallic ingots which comprises pouring the'metal in a. heated mould consisting of poor heat conducting material, covering the mould with a cover of good heat conducting material, spaced apart from the liquid metallic bath and turning the mould at so "that sudden solidificationtakes place through the whole mass of the metal. 1

2. A method of casting metallic ingots which comprises pouring the metal in a heat-- ed mould consisting of poor heat conducting material, covering the mould with a cooled cover of good eat conducting. material,

spaced apart from the liquid metallic bath and turning the mould at 180, so that sudden solidification takes place through the whole mass of the metal.

3. A method of casting metallic ingots which com rises pouring the metal in a heated mould avinna lining of poor heat conducting materia l, covering the mould with a cover of good heat conducting material, spaced apart from the liquid metallic bath and turmng the mould at 180, so that sudden solidification takes place through the whole I mass of the metal.

I aflix my si ature.

In testimony whereof ERNST R TH.

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