Improvements in the Manufacture of Steel or Iron.
Year: 1890

page_text: Date of Application, 14th Mar., 1890
Complete Specification Left, 22nd Nov., 1890-Accepted, 7th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Steel or Iron.
I, JOHN HENRY DARBY of Brymbo near Wrexham in the County of Denbigh,
Steel Manufacturer, do hereby declare the nature of this invention to be as
follows:-
This invention relates more particularly to the carbonization of steel or iron by
means of charcoal or other carbonaceous matter.
In my Specification No. 418 of 1888 1 have described a process whereby molten
steel or iron is filtered through a layer of carbonaceous material, the carbon being
dissolved or taken up by the metal and the carbonized material run into a second
ladle or cast direct into the moulds placed to receive it.
I have found this works well in practice and gives very satisfactory results.
There are however, some cases in which it is desirable to modify the mode of
adding the carbon, for instance, where existing plant does not admit of the use of
the apparatus described in my Specification No. 418 of 1888, or of the modified
arrangement described in my Application No. 20586 of 1889. Where this is the
case I propose to roughly pulverize the charcoal, gas carbon, or other carbonaceous
matter to be used, thoroughly dry it, and add a measured quantity in the casting
ladle, introducing it by means of a shovel, spout, or by other suitable means, as far
as possible below the point where the stream of metal flows from the spout of the
open hearth furnace or the Bessemer converter, or the carbon may be enclosed in a
case of thin sheet iron or other material and be thrown into the metal where it will
dissolve.
The metal after it is carbonized should be kept as free as possible from the
converter or furnace slag.
COMPLETE SPECIFICATION (AMENDED).
Improvements in the Manufacture of Steel or Iron.
1, JOHN HENRY DARBY, of Brymbo, noar Wrexham, in the County of Denbigh,
Steel Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:—
This invention relates more particularly to the carburization of steel or iron by
means of charcoal or other carbonaceous matter.
In my Specification No. 418 of 1888 I have described a process whereby molten
steel or iron is filtered through a layer of carbonaceous material, the carbon being
dissolved or taken up by the metal and the carburized material run into a second
ladle or cast direct into the moulds placed to receive it.
I have found this works well in practice and gives very satisfactory results.
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page_text: There are however, some cases in which it is desirable to modify the mode of
adding the carbon, for instance, where existing plant does not admit of the use of
the apparatus described in my Specification No. 418 of 1888, or of the modified
arrangement described in my Application No. 20586 of 1889. Where this is the
case I propose to pulverize the charcoal, gas carbon, or other carbonaceous matter
to he used, thoroughly dry it, and add a measured quantity in the casting ladle,
while the latter is being filled from the furnace or converter introducing it by means
of a shovel, spout, or by other suitable means, as far much as possible below at
the point where the stream of metal flows from the spout of the open hearth
furnace or the Bessemer converter is meeting the metal already in the casting ladle, 1
or the carbon may be enclosed in a case of thin sheet iron or other material and
be thrown into the metal where it will dissolve. In carrying out this operation
of carburising the important condition of the process is that the carbon be brought
into thorough contact with the iron and dissolved therein before coming in contact with
the slag or being otherwise oxidised. The easiest method of doing this is to keep 1
back the furnace or converter slay until such time as the carbon in the ladle has
been almost entirely absorbed or dissolved by the steel, and to effect this when pouring
from the Bessemer converter into the casting ladle the slag may be chilled in the nose
of the converter by means of cold slag or any convenient material and a scraper held
against the slag which will skim it off. The slag can then be poured on to the 2
carburised metal without any fear of troublesome boiling and chilling of the metal.
In the same way with an open hearth furnace, the flow of steel must be regulated
so that the carbon is almost entirely dissolved or absorbed before the slag is allowed to
flow into the ladle.
The proportions of the carbonaceous matter required will vary with the different 2
grades of metal but I find that about 100 lbs. of carbon added to a ladle holding
about ten tons of metal gives excellent results for 5% carbon steel.
The metal after it is while it is being carburized should be kept as free as possible
from the converter or furnace slag.
Having now particularly described and ascertained the nature of my said 3
invention and in what manner the same is to be performed, I declare that what I
claim is :-
The improvements in the manufacture of steel or iron which consists in adding a
proportion of carbonaceous material to the metal in the casting ladle in a loose or
enclosed condition substantially as and for the purpose described.
Dated this 22nd day of November 1890.
PHILIP M. JUSTICE,
55 & 56, Chancery Lane, London, Agent for the Applicant.