C90 



STEEL. 



kept at a high temperature, so that there is no stick- 

 ing of the charge to the bottom. These furnaces are 

 extensively used in this country. 



The steel used in the vessels now constructing for 

 the U. S. nary is made in ordinary Siemens-Martin 

 furnaces, Bessemer steel not as yet being used for 

 this purpose, though basic steel is used extensively 

 for ship rivets. 



The 6osic method of dephosphorization is now bo- 

 ing extensively used in the manufacture of steel in 



Fio. 6. Open-hearth Furnace. 



the open-hearth furnace, a bed of shrunk dolomite 

 or magnesia being substituted for that of gannister 

 used in the Siemens process. 



In casting steel in large masses, whether from 

 crucibles, Bessemer converters, or open-hearth fur- 

 naces, it is often difficult to obtain sound ingots, 

 especially when the steel is a mild one, the upper 

 part usually being honey-combed to a greater or less 

 degree due probably to the escape of carbonic ox- 

 ide or hydrogen gas. The necessary consolidation 

 of ingots intended for rolling or forging is effected 

 by subjecting the metal while in the mould to hy- 

 drostatic or gaseous pressure until it sets, prevent- 

 ing in this way the escape of gas, or else giving the 

 gas a chance to escape by stirring or pouring from 

 one ladle to another. Sir Joseph Whitworth applies 



Allen, of the Bessemer Works, Sheffield. He inserts 

 a ; wo-bladed propeller on the end of a vertical shaft 

 into the ladle just before casting, and stirs the metal, 

 ing the gases and thoroughly incorporating 

 all | -arts. 



This country can now produce within its borders all 

 the iron ore needed in every branch of its iron and 

 steel industries, including the finer grades of cruci- 

 ble steel. We have ores in great abundance for the 

 manufacture of acid Bessemer steel, but they are 

 confined to comparatively limited a 

 We have beds of ore for the manufacture 

 of spiegeleisen and furo-manganese, that 

 would place our country on a self-sustain- 

 ing basis, in case the foreign supply should 

 be interrupted. But the spiegeleisen is 

 not a large item in the manufacture of steel, 

 and it is more economical now to import 

 it. Great Britain is entirely without iimn- 

 ganiferous iron ore deposits. The tirst 

 steel of any kind produced in the South 

 was made with the Henderson Steel and 

 Manufacturing Company's open hearth 

 furnace at Birmingham, Ala., Feb. 27, 



IKSS. 



In 1887 the United States produced 47,- 

 I 598 tons of spiegeleisen. Ore of a charac- 

 ....... ' ter suitable for the manufacture of spiegel- 



eisen was discovered in Independence Co., 

 Ark., and railroad connections with this 

 region were completed in 1887, though all the ore 

 shipped in that year, 926 tons, was sent to the 

 Edgar Thompson furnaces at Braddock, Pa. Our 

 production of spiegeleisen since 1875 is as fol- 

 lows : 



Yean. Ton. i Yean. Ton*. 



1815.... , .......... 31,063 



--'4.574 



1876 ............... 6.1,10 



1877 ........... ... 8.845 1884 



1878 ............... 10,674 1885 ............... 84,671 



1879 ............... 13,931 I 18W! .............. 47,1183 



1880.... ...l'.i,6c:l 1SS7 ............... 47,598 



18tol ............... 21.C80I 



U 



FlO. 7. Pernot Rotary Hearth. 



the first method on a large scale ; his fluid ccm- 

 fn-tMed *le*l being subjected to a pressure, while 

 melted, of from 6 to 20 tons per square inch. The 

 density of metal is increased about -fn per cent, over 

 that cast in the open moulds. At Pittsbnrg steam 

 has been nsed, and Krnpp uses liquid carbonic acid 

 to supply the pressure. In the former the mould is 

 covered by a closed lid wedged down to form a 

 steam-tight joint, and this communicates by a flexi- 

 ble pipe with a steam-drum supplying steam at a 

 pressure of from 80 to 150 Ibs. per square inch, 

 which is allowed to act till the metal has set 



The most noticeable method of producing homo- 

 geneity in molten metal by agitation is that of Mr. 



This table shows a wonderful progress, such as 

 has never been witnessed in other great industries 

 of this or other countries. In the two years from 

 1885 to 1887 we increased our production of pig iron 

 68 i>er cent , of Bessemer steel ingots 93 per cent., 

 of Bessemer steel rails 119 percent., of open hearth 

 steel ingots 141 per cent., and of rolled iron 43 per 

 cent In these two years over 21,000 miles of new 



