US1060078A - Process of making manganese steel. - Google Patents

Description

an s reams ram-arm ora ion I ALBERT E. GREENE, F CHICAGQ, ILLINOIS, ASSIGNOER. TO AMERICAN ELECTRIC SMELT ING- AND ENGINEERING COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION Q MISSOURI.

No Drawing.

' Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in" Processes of Making Manganese Steel, of which the following is a full, clear, concise, and exact description.

My invention relates to processes of incorporating alloying metals with other metals, and particularlyto a process of making manganesesteel from ferro-manganese and molton soft steel. I

My invention is based on facts relative to alloys in general :namely, that an alloy usually melts at a lower temperature than its constituent metals"; and second, that an alloying metal may be more or less melted from the cold by pouring over it the metal, in a' molten condition, with which it,is to be incorporated, thereby producing a metal mixture having a lower melting point than said molten metal used.

It is well known that manganese steel has a very considerably lower melting point than has the soft steel with which the ferro-' manganese is incorporated to make the mananese steel, and it is a fact that by pourang' molten soft steel on solid ferro-manganese, a large part of the ferro-manganese can thereby be melted, but such a process is not ractical for the reason that neither the melting nor themixing are complete or uniform, and the composition of the steel so made is variable and almost always far too low in manganese.

My invention is an improvement over such a process as the one just outlined, rendering such a' process both practical and useful, and my process is, as far as I am aware, more economical than any other process for mak "ing manganese steel from the materials 'I have referred to, including the crucible and electric furnace processes already well known.

My invention consists in the use of electric'hea-tin combination with the heat in molten metal for the purpose of meltin an alloying metal and of obtaining uni orm compos1tion in the mixture and proper temerature control. it consists, in other words, in charging the molten metal with which the alloy is to be incorporated, upon the alley- Specification of Letters Patent.

ing metal, to partially melt said alloying metal, and then, inthe same vessel, finish-- ing the melting by means of electric heat.

In the manufacture of manganese steel, it is customary to melt the ferro-manganese in crucibles, pour the melted alloy into a large ladle, and then pour on top of it the molten soft steel, thereby producing the manganesesteel. In this process there isa considerable waste in'melting the ferro-inanganese in the crucibles and also in the mixing of the alloy and the soft steel in the ladle, the losses being due to both oxidation and to vaporization. Furthermore, the handling of the crucibles is difficult and the process is unecono'mical in many ways.

Another process which has been used to make manganese steel is to charge ferromanganese into a bath of hot steel in an electric furnace and melt the ferro by means of electric heat. One of the difiiculties involved in this procedure, namely, the heating of the soft steel to a temperature above its melting point, in an electrlc furnace into which the molten metal has been poured, so that the manganese can be thrown into the bath without remaining on the top of it, is just the difficulty it is very desirable to avoid and which I do avoid by my process. When molten soft steel is charged into an electric furnace it ver quickly cools and requires considerable e ectrical energy to re-' heat it again and especially, to superheat it. This difficulty is especially likely to be met within using an induction furnace, for the reason that the metal chills quickly on the 'top and therefore prevents the ferro-manganese from entering into the molten metal and loweringits melting point. Furthermore, when cold ferro-manganese or manganese steel scrap is thrown intoa bath of molten metal in an electric furnace there is almost invariably a loss of metal in the slag. This may occur from the admission of air during charging the alloys, or from the presence of rust on the surface of the strap, but the effect is almost invariably present unless special precautions are observed to preventit, such as the use of a reducing gas. My invention avoids, ractically entirely, these difficulties met with in the ordinary methods of procedure.

ll am aware that it has been proposed to Patented Apr. 29, 191% Application filed August 1%, 1911. Serial No. 643,345.

superheat a bath of molten iron in an electric furnace and then charge manganesecontaining metal into the bath, (see Howe, U. S. Patent No. 954,188,) but my invention is'a marked improvement over such a process. It is well known that it becomes increasingly more expensive to heat a bath of steel in an electric furnace as the temperature desired increases. It is very much easier and cheaper to highly superheat a bath of steel in an open-hearth furnace than to do so in an electric furnace, and by so doing and then pouring the superheated steel on the ferro-manganese in an electric furnace, the melting of the alloy will be greatly facilitated and then the melting and heating may be completed in a most satisfactory manner by "means of electric heat.

Iwill now describe how my process may be carried'out.

I prefer to use an induction furnace, but may use any suitable vessel, such as a ladle, heated electrically or any other kind of an electric furnace. The furnace having been previously heated, the proper weight of ferro-manganese, which would give the desired composition when incorporated with the weight of molten met-a1 to be used, is thrown into the heated induction furnace. It is preferable to heat this ferro-manganese by oil or in any other way as high as ossible without incurring undesirable oxidation. The molten soft steel, suitably low in carbon to give the proper amount of carbon in the product, is taken from any. suitable source, such as an open-hearth furnace, and is poured on top of the ferro-manganese in the electric furnace. This largely inelts the ferro-manganese. The electric current is turned on at once and the melting is completed and the temperature regulated to the desired degree.

In carrying out the process, I prefer to use a lime slag and also to use reducing gas- My process is applicable to all manner of metals, such as tool steel which is to be made with high content of alloy metals like tungsten; and the process is also applicable to the making of brass and other alloy metals.

I claim- 1. The process of making manganese steel which consists in charging solid ferro-manganese into a suitable vessel, then pouring on top of the ferro-manganese enough mol- -ten soft steel of proper composition to give the desired composition of product, thereby partially melting the ferro-manganese, and completing the melting and heating in a reducing atmosphere by means of electric heating.

2. The process of making alloy steels, consisting in charging the alloying metal into an electric furnace, then pourin on top of said alloying metal the metal with which it is to be incorporated together with a basic flux, said latter metal and flux being in a molten condition, and finishing the melting and heating in a reducing atmosphere by means of electric heating.

In witness whereof, I hereunto subscribe my name this 12th dayof August, A. D., 1911.

ALBERT E. GREENE. Witnesses:

MoCLELLANn YOUNG, GEORGE P. BARTON.