US4822A - Improvement in the manufacture of steel - Google Patents

Description

Unirse STATES PATENT OFFICE.

JOSIAH M. HEATH, OF LONDON, ENGLAND.

IMPROVEMENT IN THE MANUFACTURE OF STEEL'.

Specification forming part of Letters Patent No.4,S22, dated October 24, 1846.

To whom it may concern:

i Be it known that I, JosrAn lVIARsHnLLA HEATH, a subject of the Queen of Great Britain, and now residip'g at Winchester Buildings, in the city of London, county of Middlesex, in the said Kingdom, iron-master, have invented or discovered a new and useful invention of Improvementsin the Manufacture of Cast-Steel; and I do hereby declare that the following is afull and exact description thereof. The process -now universally in use for making cast-steel is to reduce pig-iron of suitable quality into bars of malleable iron, toy convert these bars into blistered steel, and tov melt the blistered steel, broken into fragments, in close Scrucibles, and to pour the fluidsteel into iron molds. 'The expense attending these different prlmlesses is enormous. If the cost of pig-iron et a quality suitable for good steel be eight fpounds a ton, the cost of cast-steel in` ingots `,made from such-pig-iron by the usualprocess will amount to upward of thirty pounds, or fourtimes the cost of the pig-iron.

`I have discovered a process by which the Vconversion of pig into bar-iron, of bar-iron into blistered steel, and the uselof -crucibles 'for melting'the blistercd steelmay be dispensed with, and cast-steel may be manufactured ata cost far below that of the old process. rIhis is done by melting together of mixture of pig-iron and malleable iron in such proportions that the fluid mass arising from the mixture shall contain just that amount of carbon which, when combined with iron, forms steel.

The process I now use is described `as follows: The pig-iron to be converted into steel may be melted in a cupola, or it may be run direct from a-blast-furnace used'for smelting iron ore; but the most suitable apparatus I consider to be a common cupola-furnace, blown with hot air, in order that the metal, when run from it, may retain the highest possible temperature. The fluid pig-iron should be. run from the cupola or other furnace into a receptacle. made of any material capable of withstanding an intense heat, similar in form to a common 4refinery or to the shallow well of a reverberatory furnace for melting pig-iron, and the quantity of uid pig-iron used for one operation should occupy about one-third, or thereabout, of the capacity of .the receptacle.

The interior of this receptacle and its.contents should be kept at the highest "temperature that can be produced; and I find a very ready and convenient method of producing this high temperature to-be by means of currents of l ignited carbonio-oxide gas conveyed through pipes placed round the top ofthe receptacle, slightly inclined downward, so asto bear upon the surface of the fluid metal. A sufficient temperature for this purpose may also be produced by a current of oxyhydrogen vgas yprioduced by directing "a stream of atmospheric air 'into a current of hydrogen gas formed from the decomposition of water allowed to trickle upon malleable iron brought tol a high heat. In order to burn the carbonio oxide, it

isnecessary to introduce along with it a current of hot atmospheric air; or, if a more intense heat is required, a current of oxygen gasl may be introduced along with the carbonio-oxide gas. In either case, however, care must be ltaken that the proportion of atmospheric air or of oxygen gas does not exceed that which is required to convert the carbonio oxide into carbonio acid, as any excess of oxygen Iin the blast would have a'most injurious effect upon the metal in the receptacle.

The carbonio oxide may be obtained from the high temperature required in my process of making steel as any part of my invention.

In order to decarburate the fluid pig-ironl in the receptacle to the degree necessary to form steel, I mix with it a certain portion of malleable iron, more or less as I wish to make the steel, softer or harder; but for cast-steel of 'a medium degreey of hardness, such as is used for general purposes, I find that about equal proportions of pig-and malleable iron answer best.l The proportions iniwhich the pig and malleable iron should be mixed, however,will much depend upon the qualityv of the former..v If gray pig-iron is used, it will require more malleable iron to .be 'mixed with it than Vif white pigiron is used. rlhis is a point the exact determination of which can only be arrived at bytesting the quality of the mixed fluid metal in the receptacle at intervals.

The malleable iron to be mixed with thefluid pig-iron in the receptacle may be in scraps or in any convenient form; but by far the most economical, convenient, and purest state in which the malleable iron can be used is in the granular form produced by reducing any perfectly pure oxide of iron to small fragments, and then submitting them'to the wellknown process of cementation in a commonv converting furnace, such as is used for conl verting bar-iron into blistered steel. rlhe iron .able iron on a bed between the receptacle which holds the iiuid pig-iron andthe chimney up which the waste heat from the combustion of the gas. passes. The malleable iron, when-at 'a white heat, is raked intothe. recepi,

tacle containing thel fluid pig-iron, and the whole is kept in fusion andl stirred about for a sufcient time to 'produce intimate mixture and uniformity of composition in the fluid mass 5 and when the assays taken from it show that the' steel is of the desired quality the contents of the4 receptacle are run o into molds of any form or size required. A vitreous flux'should be used to defend the surface of the fluid steel Vfrom the action of the atmospheric air while.

it is in the receptacle; but I do not claim the use of it as any part of my invention. I find common bottle glassto answer as well as anything else-` i Y The forms of the apparatus in which the' process I have above described may. be performed may be various. l have described the one I consider best adapted to the purpose;`

but I do not coniine myself` to the exclusive use of it.

In -the accompanying drawings are several views of the apparatus in which I consider the process I have described-may be mosteiciently performed. v v v- Figure 1 is a sectional plan view, (theupper part of the furnace being removed to show theinterior.) Fig. 2 is a section taken in the line l 2 of Fig. 1, and Fig.3 a section taken in the line 3 4 of Fig. l.

The letters in all the figures referto the samef parts of the apparatus.

A is the cupola, in which the pig-iron is melted; There is nothing peculiar in the form -describedand are wellknown.-

alleable iron or metal, whenrun from-lit', maylhave vthe highest possib1e-ftemperature;

VB is thebed between'the receptacle' for the .fluid metal and the..ch-imiey'..A The vmalleable iron-or'deoxidated ironIore is placed upon this `bed on either-.iside Iof the channel It S brought to the highest possible temperature by the .passage over it of, the flame from the combustion of the gasand air introduced throughthe'pipes GandII.

'C is the'receptacle into which the melted pig-iron is run from the cupola, and into which the malleable iron at a white heat is rakedv through the door `D and intimately mixed with the iiuid pig-iron by stirring .with a wooden pole. The temperature of the contents of the receptacle may be raised to any degree re .'quired` by means of the combustion'of any gas rich in carbonfandhydrogen by mixing .with

.it hot atmospheric air or oxygen gas, and the proportions required to"p1 od'uce perfect combustion of the gaswithout producing anexidat'ing Viiame maybe exactly regulatedby a. stop cock or valve, I 1,`,placed on the pipe H.

The receptaclefmay be ofI any size, according tothe quantity of steel whichgis required. Iv find the most convenientgas to be used for this .purpose is -carbonic oxide, which maybe col'- y lected from a cupola or a blast-furnace, ormay beproduced-Tin a separate furnace by the im. -perfect combustion of ,any refuse. fuel; The means of producing and applying this gas tov the purposes of solid fuel havebeenfrequentl'y l) .is the door,I bywhich the in deoxidatedgor'e isv introduced uponj the bed B,

1 and by which it'is raked into the receptacle.

E is a small door, through which a bar of ironor a wooden pole is introduced to stir the fluid y-inetal inthe receptacle. I

- F is a tap-hole by which the 'steel iisru'n' into molds from' the receptacle.

G represents Q pipes through which the car- `bonie oxideor other gas is conveyed to the receptacle. The should dip downward slight 1y, so that the ame fromthe ignited.gaamayV play upon the contents'of'the receptacle and keep the whole in ailuid state; j

, lrepresents 'pipes througn-,whiehthehot atmospheric air-or oxygen gasis .conveyedto be mixed with the gas in the. pipes G.' When atmospheric air is used, it may be, heated by the Vwaste flame which passes upthe chimney' in the pipes I. The` method of arranging th'ei gas'and air .pipes has been often described and is well known.

K is the channelthrough which the liquid pig-iron is run fro'm'the lcupola or blast-furnace into the. receptacle.-

L is a valve by whichthe admission of hot atmospheric air oroxygen gas is regulated, so as'to produce perfect combustion.

The exclusive right of preparing east-steel by decarburating pig-iron to the degree. re-

if" quired to form steel lby mixig with the pig-` SHALL HEATH, have hereunto setmy hand and lirogi run from afclipolafoi' otherfurnace ito a' seal this 18th day of February, 1846; separate receptacle malleable'iron 'in the pro- Witnesses: J. M. HEATH. [L 5.]

portion neeessary'to form steel, and running, v .l C., WINTERBOTTOM, the mixtre of pig and .malleable iron, while 2 Wnchester Building, Gld Broad S12.` still fluid and ,in tlieA state of cast-steel, `into`- FRED'WALKORN, f molds from vthe receptacle. i y' 's Clerk to Newtonon, Patent Agents, Chancery `In witness whereof Lathesaid JOSIAH MAR- f Lane. v

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