896 



STEEL 



Fig. 1902 shows the fire itself, with the metal, charcoal, and blast. A is a bottom 

 of charcoal, rammed down very close and hard. B is another bottom, but not so 



1900 



1901 



\ 



CS! 



e s 



closely beaten down ; this bed of charcoal protects the under one, and serves also to 

 give out carbon to the loop of steel during its production, c is a thin stratum of 

 JQ02 metal, which is kept in the fire to surround the loop. 



D shows the loop itself in progress. 



When the fire is hot, the first operation is to melt 

 down a portion of pig-iron, say 50 to 70 pounds accord 

 ing as the pig contains more or less carbon ; the char- 

 coal is pushed back from the upper part of the fire, and 

 the blast, which is then reduced, is allowed to play upon 

 the surface of the metal, adding from time to time 

 some hammer-slag, or rich cinder, the result of the 

 previous loop. All these operations tend to decarbonise 

 the metal to a certain extent; the mass begins to 

 thicken, and at length becomes solid. The workman 

 then draws together the charcoal and melts down 

 another portion of metal upon the cake ; this operation renders the face of the cake 

 again fluid, but the operation of decarbonisation being repeated in the second 

 charge, it also thickens, incorporates itself with the previous cake, and the whole 

 becomes hard ; metal is again added until the loop is completed. During these suc- 

 cessive operations, the loop is never raised before the blast, as it is in making iron, but 

 it is drawn from the fire and hammered into a large bloom, which is cut into several 

 pieces, the ends being kept separated from the middle or more solid parts, which are 

 the best. 



This operation, apparently so simple in itself, requires both skill and care ; the 

 workman has to judge, as the operation proceeds, of the amount of carbon which he 

 has retained from the pig-iron ; if too much, the result is a very raw, crude, un- 

 treatable steel ; if too little, he obtains only a steelified iron ; ho has also to keep the 

 cinder at a proper degree of fluidity, which is modified from time to time by the 

 addition of quartz, old slags, &c. It is usual to keep from two to three inches of 

 cinder on the face of the metal, to protect it from the direct action of the blast. The 

 fire itself is formed of iron plates, and the two charcoal-bottoms rise to within nine 

 inches of the tuyere, which is laid flatter than when iron is being made. This 

 position of the tuyere causes the fire to work more slowly, but it ensures a better 

 result. 



The quantity of blast required is about 1 80 cubic feet per minute. Good workmen 

 make 7 cwts. of steel in 17 hours. The waste of the pig-iron is from 20 to 25 per cent., 

 and the quantity of charcoal consumed is 240 bushels per ton. The inclination of 

 the tuyero is 12 to 15 degrees. The flame of the fire is the best guide for the work- 

 men. During its working it should be a red bluish colour. "When it becomes white 

 thofire is working too hot. 



When, care has been taken in melting down each portion .of metal, and a complete 

 and perfect layer of stee 1 ! has been obtained after each successive melting, when the 

 cinder has had due attention, so that it has been neither too thick nor too thin, and 

 the heat of the fire regulated and modified during the progressive stages of the 



