COLI-KCTIONS IN KCONoMIC (JF.OI,* KJ V AND M 1'. TA l,l-ri{( i V. 1 !.'» 



Ill many cases llic tnl.il umiidx al ul' t lie cailioii lias ;iiH>t lirr adxaii 

 ta;;*', ill Iliat al tlu' saiiu' tiiiu' iiiipiiritics an- it'iiioviil iKtm the iiiclal, 

 and tliiis a lowci- made of pi^^ iron can l»c iitili/c<l. 



TlIK CKMKNTATION SIKKI, I'KOi'KS.S. 



In tilis process liars of pnddled iron are first exposed to a t»'iiipera- 

 ture of about l.HK) ' (\ after Itein^ jiacUed in iron boxes witii charcoal. 

 I»y this operation tlic caritoii of tiie cliarco.d enters tlie bar-iron and 

 ijradnallv clianj^'cs it to steel. 



The time required di'iiends ii|ioii the ;;iade ol siecl [n be produced 

 or tiie amount of carbon the steel must <!ontain. .Vii ordinary char^^c 

 of IL' to 18 tons will be converted into sprin<? steel in about 7 days 

 and will contain about one half per cent, of carbon, while the hij,Miest 

 ^M'ade or nieltinj;- heat steel recjnires 1» to 10 days and will contain l.\ 

 per cent, of carbon. When the conversion is completed the furnace is 

 cooled ami the bars removed. 



The smooth bars of wroujihl iron will n(»w be found covered with 

 blisters, and this material is freijueutly called blister steel. Thechar- 

 acier of the blisters iudiciites the quality of the steel, but the (piality of 

 a char^'i' is never uniform through the wltole mass. 



The blister bars are now br(»ken and sorted accordini;' to fracture. 

 Sometimes these pieces are piled or fa^ioted and rolh-d directly to bar 

 steel, but this treatment alters the «^rade of the metal, and, owin.^ to 

 the lack of uniformity in the blister steel, the product is not at all uni- 

 form, so that it is more common to cut the bars of blistered steel into 

 small [)ieces, charge them into crucil)les with certain additions. especially 

 inanj;anese ore and ferromanjianese, to imj)rove the (piality, and then 

 to melt them. 



The melted stetjl is cast into inj^ots and is then ordinary cast-steel. 

 Cast-steel is, however, frequently produced by other processes: the 

 wold "'cast'' simply means that the steel has been melted. 



This process is illustrated by a collection from the Crescent Sti-el 

 Works of .Miller, Metcalf & Parkin, Pittsburjr, I'euusylvauia. 



(1) I'ii^ iron, ii.si-il for iiiiikin^ pmldltiil Itar-iroii. (r>'140U.) 



(2) PiuliIlcMt Itar-iron, \\hci\ fur ennvcrsion into lilisfcr stivl in (•(Miu'ntiiijj nvrns. 

 (54401.) 



(:i) Ciluler, luudiiceil in iiiiikiii;^ ImiiUIUmI liai-inm. v-"»ll"- ) 



(4) Cinder, IianiiiKTed from tin- puddled liall in niakiii^ puddled liar. (.."i440:i.) 



(.'■>) Hlister Hlt'd, after jiassin^^ tliron^li tin- cciMi-ntin^^ fnrnaee. (.'i|ju4.^ 



(<>) Cliarcoal, nsed to impart <ariion to the metal in the eonverHion of har-iron into 



stotd in the <'em«'ntiii>j fnriuice. (."i4IO.'» ) 



(7) Ca.st .steid, a piece of ingot hh ea.st iroux tlie ineMin^i jto". (o4408.) 

 •') Man;ianese ore. n.seil in tin- erncilile wlii'u mtdtiiif,' Idister .steel. (.">44i»(i.) 

 .1) lM'rromaii<;anese, an .illoy of iron and m.inj^anese nsed in tiie rrneildf when 



nieltiiif; Idister steel. (frMO".) 



(Ill) CiiidiT, produced in melting idister .steel in criKilihs. ^."itliili. 



( 11 ) Cnicilde steel, an in;;ot of cast h(co1 wliich liiw been bented and hainnKred to 



close up gas hubhles ( Idfwlioles), .soiiietiines callecl welding. i.'>l41i».; 



