US987549A - Iron manufacture. - Google Patents

Description

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Para smut.

ROBERT BI CARNAHAN, JR., OF MIDDLETOWN, OHIO, ASSIGNOF. TO .THE INTERNA- TIONALMETAL PRODUCTS COMPANY, OF NEWARK, NEW JERSEY.

. men MANUFACTURE. 1

Specification of Letters Patent. Patented MIar. 21, 1911.

No Drawing. Application filed October 22, 1.908, Serial No. 459,056. Renewed February'B, 1911. Serial VT 0 all whom 'it may concern:

GAnN AHAN,

Be it known that I, ROBERT -13, J in, a citizen of the United States; residing ,at- Middletown, Butler'lcounty, Ohio, have invented certain new and useful Improve;

in'ents in Iron Manufacture iof which the following is a specification.

the product-ion of an extraordinarily high grade of rolling mill and bloomery iron from comparatively low priced, material and by a method characterized by special economy and regular certainty of result, will be readily understood from the following description.

.' -My improved method of I manufacture Which-(l5 a process of elimination from start to finishmay be carriedputas follows T .per cent.

charge.

First-{employ a high pow r ble of what might be termeil a particularly 'fierce action, by preference a gas fired basic open-hearth furnace.

Second, charge the furnace" with pig iron or cast iron or molten iron or other carbonbearing 7 iron reduced" from ore, preferablyemploying iron whose phosphorus and sulfur and silicon do not aggregate over 3.05

stitu'ted'iron or steel melting stock or mixed scrap 'to the extent of per. cent. of the X Third, charge 111118 or limestone to reduce sulfur'and phosphorus,the lime or limestone being preferably charged prior tocharging the metal.

Fourth, melt the chargeand, by the em-| ployment of iron ore, refine -it as in the operation of the usual process for making mild steel, and, as in'that process, the iron ore may be all pharged into the molten bathor some of it may be charged prior to or along with, the charging of the metal.

Fifth, refine to the stage usual at the point of tapping for high grade. mild steel, say .10 to .15 per" cent. carbon. I

Sixth, thereafter continuously raise the;

temperature as the carbon becomes reduced, continuing the operation till analysis by bath test shows that the sulfur, phosphorus, manganese, carbon and silicon do not in the aggregate exceed .14: per cent. The time required will be very much lessened if iron ore in excess is continuously added in thepres'ence of the increasing temperatures.

furnace capa-.

In practice 1 have, in cases, subin practice find theperiod of treatment sumes from one to four hours more time than is employed in making high grade The present invention, comprehending mild Steel. I

Seventln; let the tapping temperature reach about 2850 deg. F., and tap the melted hot charge into a ladle or other receptacle.

Eighth, pour into ingot molds while still at high temperature, not below 2775 deg. F.

Ninth,v degasify the molten metal, say with aluminum, in the same manner as in ordinary open-hearth practice with mild structive to furnaces, very muchmore so than anything met with in usual operations in theproduction of mild steel. -My experience up to-the present time indicates that myprocess is about three times as destructiae to furnace roofs as are the usual'processe s with similar furnaces.

I have above referred to a temperature of 2850 deg. F. for the bath and this is correct as far as l have been able to ascertain from the most reliable authorities and 8 5 literature. In practice, correct temperaturemay be determined by stirring the bath with an iron rod one and one-eighth inches in diameter for-one minute and a' quarter.

If about eighteen inches of the rod has been melted ofl and if the fluxed rod end has a glassy appearance the temperature is correct. A more rapid or slower cutting away ofthe rod indicates thatthe bath is too hot or too cold.

.The poured ingots represent a product extraordinary in the art, and the extraordinary characteristics of these ingots can be secured with a degree of regularity and certainty quite unattainable in any prev ously known commercial inethod for theproduction of iron having their character istics. "(The bodies of the ingots are free of slag. The heads, of the ingots involved at the end of a pouring may show a trifle of slag but this is harmlessand drops off in the heating and working 'of the ingot and never enters the worked product. The

, extraordinary ularly producing a temperatures bodies of the ingots Will be found free from s lag,'thus far detected by themicroscope in the hands of a professional metallographist which is, of course, the case also with products worked from the ingots. Briefly, the product of my improved method is iron of a purity exceeding that of thevery hi hest grade of Swedish charcoal iron: an

and uncertainties incident to other methods of producing these high grade irons, and my improved method is vastly more economi cal. The method is capable of yielding a product whose percentage of iron' is almost identical with iron by hydrogen!" My improved method provides, for the first time in the history of-the art, so far as I am apprised of it, for thetcommercial production in an'open hearth furnace of a product heretofore arrived at onlyin the laboratory. This may be judged of by the fact that, Without considering the more refined capacities of my method, I am in every day practice in anopen" hearth furnace regproductanalyzing as follows k S1l1con .Trace.

Manganeseu'un .010 Sulfur .019 Phosphorus a .003 Carbon a .027 Iron (by difi'.) 99.941

Fourth will galvanize more satisfac-- torily than me.

Fifth :resi sts all corroding a cuts to an degree, being in t vastly superior to. anycommercial steel known to me, and equal to the very highest grades of Swedish charcoal iron. Sixth :forges and rolls with facility at any comnlr ercial iron 'known to ear/tee the ,manufacture is not subject to the variations 5 use in making *step's:--first, in

open hearth furnace w th iron: second, in

than steel, thereby cident tothe employment 0 high tempera,- tu'res. The material is especially adapted for smooth sheets comparatively free from scale, being, it isjbelieved, superior in this respect to any iron or mild steel known to the art.

ternal electrolysis.

Eighth: welds perfectly'with a flux,-but

charcoal or puddled iron without a-fl'ux.

Ninth :The product well lends itself to crucible steel, being superior to ordinary iron and muc more economical than charcoal iron.

Tenth :the microscope has detected no slag in the body ished product.

Eleventh:the material combines in a most remarkable degree the most valuable qualities of commerciallmild steel and the most valuable qualities ofthe best commercial iron, with apparently none of the many of the ingot or in the finundesirable qualities of either.-

The improved method of producing rolling-mill and bloomery ingots of specially high-purity iron consisting of the following charging a highpowered employing therewith eliminating agents for carbon and manganese and sulfur and phosphorus: third, in refining the charge in strength somewhat higher.

' p iorus, manganese, carbon is respect .niolten condition till carbon is about .10 per cent: fourth, in continuing the refinement atcontinually increasing he attill analysis by bath test shows that the sulfur, phosand silicon do .not in the aggregate exceed .14 percent.. and with an ultimate bath temperature of at least 2850 deg. fifth, in pouring the metal being treated with a degasifying agent while in molten stateafter tapping from the furnace, substantially as set forth.

. lVitnesses: 3

considerably lower than high ELMER RQSHIPLEY, M. S, .BELPEN.

'Seventh:substantially proof against in grade charcoal iron ai'id; very much: lower avoidln the scalingin without. a flux it welds less perfectly than hot purified metal into ingot molds, the

wRO BERT 'BfCARNAHAN. JR.