US1131799A - Method of making alloys. - Google Patents

Description

UNITED STATES PATENT OFFICE.

ARCHIE SMITH, 0F LEETONIA, OHIO, ASSIGNOR TO THE YOUNGSTOWN IRON & STEEL COMPANY, OF YOUNGSTOWN, OHIO, A CORPORATION OF OHIO.

METHOD OF MAKING ALLOYS.

Be it known that I, Anomr. Siurru, residmg at Leetonia, in the county of Uolumlnana and State of Ohio, a citizen of the United States, have invented or discovered certain new and useful Improvements in Methods of Making Alloys, of which improvement. the following is a specification.

My invention relates to the production 01 metallic alloys and its object is economy of manufacture and the obtaining of a product of high quality.

In the production of steel alloys, such as silicon-steel, vanadium-steel, etc., as-nou' carried on, molten steel is tapped from the furnace in which it has been refined-an open-hearth furnace, for example-into a ladle in which the other ingredient of the desired alloy (silicon in the form of ferrosilicon, for example, or vanadium in the form of a relatively rich iron alloy. or the alloying metal in pure and unalloycd form) has first been placed.

My invention consists in tapping the furnace, not directly into the ladle in which the alloy is to be formed, but into an intermediate ladle. from which it is teemcd in turn into the ladle containing the other ingredient or ingredients.

The advantages of the method of my invention over that which has heretofore obtained maybe brieily stated: When a tur nace such as an open-hearth furnace is tapped, the stream of metal which lows from it carries a considerable quantity of slag. Under practical working conditions it is impossible to draw the metal from the furnace wholly tree of slag: and. if the furnace be tapped at a relatively low temperature-as is the practi e in making silicon steel for instance. much greater quantities of slag escape with the metal drawn otta condition of things quite beyond the power of the operator to control or prevent.

The dag from the refining furnace and material furnished for forming the intendcd al ovt'cr o-silicon. vanadium or the lil e-havc great atlinity the one for the othcr: and. when a body of molten steel carrying with it quantitie of slag is'introduccd into a ladlc containing material of the charm'tcr indicatcd. a portion of that material. instead of alloying with the refined steel, L'Ollltllllt\ with the slag. Thus the re- Specificatien of letters Patent.

Patented Mar. 16, 1915.

Application filed September 18, 1914. Serial Ne. 862,384.

sulting alloy is impoverished and the value of much expensive material is lost.

When the furnace-charge has been tapped into an intermediate ladle, the slag may be separated. For instance, a steel ladle is ordinarily provided with a nozzle in its bottom and with a stopper which may be moved to open and close the nozzle at pleasure; and, since the slag rises and floats on the body of refined metal, the latter may be drawn ofi' free of slag and thus introduced into the ladle where the alloy is formed.

A further advantage which the method of my invention possesses over the method of manufacture which has heretofore obtained (and herein lies the utility of my invention in more specific form) is that it makes possible the use of a refining furnace of any size. Heretot'ore, in making silicon steel (for example) conditions of manufacture have required the refining the steel in small furnace chargcs-charges of about twentyfive tons as a maXimum-and for this reason: IV hen the furnace is tapped,

the entire charge must be drawn otf: and, if

it be drawn directly into the alloy-forming ladle, the ladle must of necessity be of a capacity to take the entire charge. Now in the alloying of steel with certain metals (silicon..for example) the immediate effect of teeming molten steel upon the silicon ingredient (ordinarily in the form of ferrosilicon) is high fluidity; the mass of mingled metal is immediately much more fluid (and, as I believe. hotter) than the mass of molten steel tcemed into the mixing ladle. This highly lluid mixture is dillicult of retention for any considerable length of time in the mixing ladle: for (whether because of its fluidity, its temperature, its chemical atFmities. or for other reason. is immaterial) it tends to rapidly destroy the stopper or other closure of the ladle and to escape. To reduce to a minimum the ctl'ects of this tendency. at least three expedients are resorted to. One expedient is to teem the mixture from the ladle after a very short interval of time: but here the ditliculty is that an appreciable interval of time is rcqui ite (about ten minutes, more or lcssl for the thorough mingling ot' the components to form an alloy of good quality throughout. second expedient is to tap the furnace at low temperature; but the ditlicultics are that the intimate union of the components then proceeds more slowly and that under such conditions greater quantities of slag gain access to the mixing ladle, with the ell'ect of impairing the quality of the alloy, as I have explained. The third expedient is to use a small furnace charge--becausc a smallacfuantity of metal cools more rapidly than a large one. As I have said, in the present state of the art the conditions indicated compel the operator to use furnace charges not greatly cxceedin tu'entyfive tons as a maximum. Manilcstly, operation with large furnace charges is (other things being equal) far more economical than with small.

I have said that because of conditions heretofore diliicult to deal with, the male ing of silicon-steel has been limited, and furnace charges not exceeding twenty-five tons have been found a matter of necessity. In making certain other steel alloys, and because or conditions such as I have indicated, the practice has been to prepare the relined steel in crucibles-mud, compared with open-hearth practice, the practice of pre 'iaring the metal in crucibles is very costly.

By the use of an intermediate'ladle (in the use of which my invention lies) the intermediate ladle may be made of a size commensurate with any furnace charge, and with a large intermediate ladle any number of small alloying ladles may be employed, and one or any number (up to the capacity of the intermediate ladle) of alloying .ladlcs may be charged from the single intermediate ladle. Following this procedure a furnace charge of most economic size may be refined, and the alloy may be produced in ladle-units of most economic size; while those matters of temperature at the time of tapping the furnace, the elimination of slag, temperature of the steel when introduced to the alloying ladle, the period during which the components of the alloy mingle, and the temperature of c; ":ing the alloy from the ladie-all of these things may be controlled at pleasure, freed of those limitations and interpendcncics which i have hereinabm'e indicated.

Following the method which described, I have refined furnam; charges of seventy-iive tons and used a plurality of alloy mixing adles earl; of a cl'ipacit s not exceeding twenty-liretons. and in so doing have realized appreciable economy over the incexisting method in which, as l hare said, the size of the furnace-charge is limited to about twenty-five tens as a practical maximum.

It will be understood that the metal in the intermediate ladle need not be used, all of it, in making alloy, but only so much as desired; the remainder being cast directly into ingot molds or dealt with in any other desired manner.

It will further be understood that the \vitlnlrawing of molten metal from the intern'iediate ladle to the alloy mixing ladle need not be'dclayed (if such delay is undesirable) but may begin while the tapping of the furnace is still in progress; ordinarily, however, the tapping of the furnace to the intermediate ladle will be completed before the Withdrawingof metal to the mixing ladle begins.

I claim as my invention:

1. The herein described method of producing high-silicon steel which consists in completely refining in a single furnace a charge of steel exceeding twenty five tons, drawing the entire charge into a single receptacle, removing a fraction of such charge from said receptacle into a second and alloy ing receptacle, and combining a silicon in gredicnt with such fractional charge While in said second receptacle.

2. The herein described process for the economic production of high-silicon steel which consists in refining in a suitable furnace a charge of steel exceeding twentyfive tons, of drawing the entire furnace charge when refined into a single all-containing ladle, and of drawing from that ladle into a second alloy-forming ladle a ladle charge not exceeding twenty five tons and there combining the molten steel with siliecn.

23. The herein described process of production of higlrsilicon steel which consists in completely refining in an opcnhearth furnace a charge of steel exccedii'ig twentydive tons, drawing the entire charge when completely refined into a single ladle, drawing from said ladle into amther receptacle a fraction of such ladle charge and there combining it with a silicon ingredient.

In testimony whereof I have hereunto set my hand.

ARCHIE SMITH,

Vitnessrs:

(Maniacs A. PALMER, Sn) TL Lac-nuax.

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