THE ROYAL ARTILLERY INSTITUTION. 
303 
HEATON’S STEEL CONVERTING PROCESS. 
COMMUNICATED BY CAPTAIN KEATE, R.A. 
A concise account of a new method of steel manufacture, u Heaton’s 
Steel Converting Process, 55 which has very recently come into operation, 
may perhaps be considered of interest to the readers of these papers. 
In order to estimate the invention at its full value, the hitherto existing 
processes, with their scope, should for a moment be considered. 
The oldest of these, that by cementation and puddling, involves a series 
of tedious and laborious operations; the crude iron having first to be 
deprived almost wholly of its carbon, and then, by the costly method 
of cementation, made to absorb a sufficient quantity of that substance in a 
solid state. It is capable, moreover, of dealing with certain of the purest 
brands of iron only, obtained from a contracted area. With variations and 
modifications in detail, this was the only method of steel making till 
Mr Bessemer took the iron world by storm in 1855, with the introduction 
of his ct Pneumatic Process, 55 which, as is well known, consists in the forcing 
of air by steam power through the molten cast-iron, so that it is thereby 
converted into oxide of iron, which re-acts on the silicon and carbon, con¬ 
verting the latter with carbonic oxide, which burns out at the mouth of the 
furnace, and the former into siluric acid, which comes to the top with the 
slag, and the metal is thus rendered malleable and ready for the tilt hammer 
at a single heat. The process of blowing a charge of five tons with a 250 
horse power engine, takes about a quarter of an hour, after which, as it is 
found that the metal has become too much decarbonized, the converter has 
to be “ turned down 3> to receive a dose of spiegeleisen to restore the balance. 
The conversion into steel is then completed, but in pouring it from the 
converter into the crane ladle, which is the next operation, a great amount of 
slag often accompanies it. This is stated to be due to the wearing down of 
the lining and the tuyeres at the bottom of the converter, which have to be 
renewed at least every two days. The steel is next run from the ladle 
through a perforated plug of fire clay, into moulds of cast-iron of suitable 
sizes for forgings of different kinds. 
It is unnecessary to detail the subsequent mechanical processes of 
re-heating, rolling, hammering, and the like, which are common to all steel 
manufactures, but it is important to note the admixture of spiegeleisen. 
without which the conversion cannot be satisfactorily effected, the destruc¬ 
tive action of the process on the converters, and the wear and tear of the 
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