IMPROVE- MENTS IN THE CONVERSION OF WROUGHT OR MALLEABLE IRON INTO STEEL, AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN
Year: 1865

page_text: LETTERS PATENT to John Jobson, of the Derwent Foundry, Derby, and,
John Farmerley Dickson, of Leicester, for the Invention of "IMPROVE-
MENTS IN THE CONVERSION OF WROUGHT OR MALLEABLE IRON INTO STEEL, AND
IN THE MEANS OR APPARATUS EMPLOYED THEREIN."
Sealed the 13th October 1865, and dated the 5th July 1865.
PROVISIONAL SPECIFICATION left by the said John Jobson and John
Farmerley Dickson at the Office of the Commissioners of Patents, with
their Petition, on the 5th July 1865.
We, JOHN JOBSON, of the Derwent Foundry, Derby, and JOHN FARMERLEY
DICKSON, of Leicester, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONVERSION OF WROUGHT OR MALLEABLE IRON INTO STEEL,.
AND IN THE MEANS OR APPARATUS EMPLOYED THEREIN," to be as follows :—
The improvements relate to the conversion of wrought or malleable iron into,
steel by passing carburetted hydrogen gas over red-hot iron contained in a
closed vessel or chamber..
In attempts heretofore made to convert iron into steel by the action thereon
of carburetted hydrogen gas in close chambers a great difficulty has arisen
from the explosive properties of such gas when brought in contact at a high
temperature with atmospheric air. This property of this gas renders it
dangerous to open the retorts while at a red heat, either for the purpose of
extracting trial bars or other forms from or for emptying or re-charging them,
and renders it necessary first to cool the carburetting vessel or chamber, thereby,

page_text: causing a great waste of time, labour and fuel, and still further expense in the
increased tendency to destruction of the furnaces and vessels or chambers
employed.
The object of our improvements is to remedy these evils, as well as to
obtain security in the employment of this process of conversion, by enabling
the carburetting vessel or chamber wherein iron is being converted into steel to
be opened when desired during the converting operation without necessitating
such previous reduction of temperature. To effect this end, when the car-
buretting vessel or chamber is desired to be opened, we first shut off there-
from the supply of carburetted bydrogen gas, and according to one method
we admit therein instead a current of a non-inflammable gas, or a gas which is
only inflammable at a very intense heat; using for this purpose by preference
nitrogen gas or ammoniacal gas, and to an extent to fully drive out therefrom
the carburetted bydrogen gas. When this has been effected the vessel or
chamber may be opened with safety and its contents taken out.
In re-charging the said carburetting vessel or chamber, whilst still red-hot
we proceed as follows:-After the charge has been placed in, and whilst the
said vessel or chamber is still full of atmospheric air, it is closed-and- made
impervious to the external atmosphere; we then pass gas, such as referred to,
into it in such quantity as to drive out the atmospheric air contained therein,
and when this is ascertained by appropriate tests (of which, in the case of
ammoniacal, gas, muriatic acid applied on a brush or feather to the aperture
through which the gas escapes is a convenient one) the carburetted hydrogen
gas may be. safely admitted into the red-hot vessel or chamber, and the con-
verting process. will proceed as before.
By another method we apply to one end of the converting chamber or
retort a passage of small area, or covered with fine reticulate work, and having
cut off the supply of carburetted hydrogen gas to such chamber or retort, we'
apply a light to this aperture when a flame will be generated to consume the
carburetted hydrogen remaining in the chamber or retort, and we drive out
such gas by means of a small current of atmospheric air, which is admitted
into the chamber or retort at the opposite end to that of the aperture for the
flame, and this current of atmospheric air is by preference passed through a
tube in the chamber or retort so that the air therein becomes highly heated
before it escapes into the chamber or retort. In re-charging, having intro-
duced into the chamber the articles to be acted upon by the carburetted
hydrogen gas, we close such chamber and leave the heated carbon deposited
from the gas in the chamber to absorb the oxygen of the atmosphere, leaving
only the nitrogen and carbonic acid; and when this is fully accomplished,.
a

page_text: which under ordinary circumstances will take 10, to 20 minutes, the. car.
buretted hydrogen may be admitted.
In some cases it is desirable to convert only portions of articles into steel,
leaving other portions thereof unconverted or in the condition of simply wrought
or malleable iron; to effect this we apply to those portions of the surfaces of
the articles to be acted upon which are to remain unconverted a. composition
obtained by the admixture of equal parts of the oxide of tin and clay, pre-
ferring for the purpose pipe or fire-clay brought to a pasty consistency by. the
addition of a strong solution of silicate of soda or potash.
We form the converting chambers by preference with mouths at each end
thereof for the convenience of emptying 'them by facilitating the pushing
of the bars or other articles from one end of them out at the other, and we
obtain the openings or mouth-pieces to the converting chambers gas-tight
by applying to each of them two or more plates at distances apart one within
the other in each mouth-piece; the space between these plates being filled in
with suitable. non-conducting material (for which purpose moulding sand
answers well) by which the. chambers are rendered gas-tight, and the flow of
a current of gas through them may be secured by causing it to pass therein
through an opening provided for the purpose in a mouth-piece at one end and
therefrom at a corresponding one at the opposite end.
:
The improvements are also applicable when employing cyanogen or
other converting gases or combinations thereof in place of the carburetted
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Jobson and John Farmerley Dickson; in the Great Seal
Patent Office on the 4th January 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
JOBSON, of. the Derwent Foundry, Derby, and, JOHN FARMERLEY DICKSON, of
Leicester, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of July, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said John Jobson and John Farmerley Dickson, Her special licence, that
we, the said John Jobson and John Farmerley Dickson, our executors,
administrators, and assigns, or such others as we, the said John Jobson and

page_text: John Farmerley Dickson, our executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all
times thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for "In-
PROVEMENTS IN THE CONVERSION OF WROUGHT OR MALLEABLE IRON INTO STEEL, AND
IN THE MEANS OR APPARATUS EMPLOYED THEREIN," upon the condition (amongst
others) that we, the said John Jobson and John, Farmerley Dickson, our
executors or administrators, by an instrument in writing under our or their
hands and seals, or under the hand and seal of one of us, or them, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and im-
mediately after the date of the said Letters Patent.
NOW KNOW YE, that we, the said John Jobson and John Farmerley
Dickson, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, that is to say :-
These improvements relate to the conversion of wrought or malleable iron.
into steel by passing carburetted hydrogen gas over red-hot iron contained in :
a closed vessel or chamber.
We would here remark that a Patent for the conversion of iron into steel
by the use of carburetted hydrogen gas in a closed chamber was granted to
Charles Mackintosh, dated the 14th day of May, 1825, and for such method
of obtaining the conversion of iron into steel, when separately considered, we a
lay no claim. In attempts heretofore made to convert iron into steel by the
action thereon of carburetted hydrogen gas in close chambers a great
difficulty has arisen from the explosive properties of such gas when brought
into contact at a high temperature with atmospheric air. This property of
this gas renders it dangerous to open the retorts while at a red heat either s
for the purpose of extracting trial bars or other forms from or for emptying
or re-charging them, and renders it necessary first to cool the carburetting
vessel or chamber, thereby causing a great waste of time, labour, and fuel, and
still further expense in the increased tendency to destruction of the furnaces
and vessels or chambers so employed.
The object of our improvements is to remedy these evils, as well as to
obtain security in the employment of this process of conversion, by enabling
the carburetting vessel or chamber wherein iron is being converted into steel
to be opened when desired during the converting operation without necessi
S

page_text: tating such previous reduction of temperature. To effect this end, when the
carburetting vessel or chamber is desired to be opened, we first shut off there-
from the supply of carburetted hydrogen gas, and according to one method
we admit therein instead a current of a non-inflammable gas or a gas which is
only inflammable at a very intense heat, using for this purpose by preference
nitrogen gas or ammoniacal gas, or it may be steam, and to an extent-fully
to drive out therefrom the carburetted hydrogen gas. When this has been
effected the vessel or chamber may.be opened with safety, and its contents
taken out.
In re-charging the said carburetting vessel or chamber while still red-hot
we proceed as follows:-After the charge has been placed in, and whilst the
said vessel or chamber is still full of atmospheric air, it is closed and made
impervious to the external atmosphere; we then pass gas, such as already
referred to, into it in such quantity as to drive out the atmospheric air con-
tained therein, and when this is ascertained by appropriate tests (of which, in
the case of ammoniacal gas, muriatic acid applied on a brush or feather to the
aperture through which gas escapes is a convenient one) the carburetted
bydrogen gas may be safely admitted into the red-hot chamber or vessel, and
the converting process will proceed as before.
By another method we apply to one end of the converting chamber or retort
a passage of small area, or covered with fine reticulate openwork, and having
cut off the supply of carburetted hydrogen gas to such chamber or retort, we
apply a light to this aperture, when a flame will be generated to consume the
carburetted hydrogen gas remaining in the chamber or retort, and we drive
out such gas by means of a current of atmospheric air which is admitted into
the chamber or retort at the opposite end to that of the aperture for the flame,
and this current of atmospheric air is by preference passed through a tube in
the chamber or retort, so that the air in the tube may become highly heated
before it escapes into the chamber or retort, when the oxygen contained in the
atmospheric air will combine with the heated carbon present and become
converted into carbonic acid. In re-charging, having. introduced into the
chamber the articles to be acted upon by the carburetted hydrogen gas, we
close such chamber and leave the heated carbon deposited from the gas in the
chamber to absorb the oxygen from the atmospheric air, leaving only nitrogen
and carbonic acid in the retort.. When this is fully accomplished,. which will
vary in time according to the temperature of the retort, the carburetted
hydrogen gas may be safely admitted. From 10 to 20 minutes we have
found to answer the purpose. The process of conversion may be expedited
by using the converting gas under pressure; but we do not claim the appli,

page_text: cation of such pressure as a part of our Invention. The useful quality or
character of the converting gas for the time in the converting chamber for
the purpose of acting as stated in the process of conversion may be ascer-
tained by observing the colour of flame produced by the ignition of a jet of such
gas as it passes from such converting chamber. When such gas-is exhausted
of its carbon or the carbon has been fully dissociated from it or decomposed
in the converting chamber by the process of conversion the color of flame
obtained. will be a pale blue. We find the process of conversion to proceed
more efficiently when the color of flame obtained, as stated, is a. deep
yellow.
In some cases it is desirable to convert only portions of articles into steel,
leaving other portions thereof unconverted or in the condition of simply
wrought or malleable iron. To effect this we apply to those portions of the
surfaces of the articles to be acted upon which are to remain in, an uncon-
verted state a composition adapted, where applied, to prevent access of the
carburetted bydrogen gas to the red-hot iron.
The following mixture we find convenient for the purpose:—
Oxide of tin
1-part.
Silicate of soda
Clay
•
->
-
8
"7
1
''
to which may be added powdered glass 1 part, borax 1 part.
In proceeding to use this mixture we first clean the article or parts of the
article to be protected by removing any grease, oxide, or dirt adhering by
brushing over or applying hydrochloric or sulphuric acid, and afterwards
removing the acid by washing with water, the parts desired to be protected
are then covered with a strong solution of a gummy or pasty matter, upon
which the protecting mixture is applied, and when dried at a gentle heat the
articles are placed in a red-hot chamber or muffle until the mixture is fluxed,
and if, upon examination, it is found not to be sufficiently covered the operation
is repeated.
We form the converting chambers by preference with mouths at each end
thereof for the convenience of emptying them by facilitating the pushing of
the bars or other articles from one end of them out at the other, and we
obtain the openings or mouth-pieces to the converting chambers gas-tight, by
applying to each of them two or more plates at distances apart one within the
other in each mouth-piece. The space between these plates being filled in
with suitable non-conducting material (for which purpose moulding sand
answers well) by which the chambers are rendered gas-tight, and the flow of a
current of gas through them may be secured by causing it to pass, therein

page_text: through an opening provided for the purpose in a mouth-piece at one end,
and therefrom at a corresponding one at the opposite end or other suitable
place.
The improvements are also applicable when employing cyanogen or other
converting gases or combinations thereof in place of the carburetted hydrogen
gas. When it is] desirable to hasten the converting process we mix with
the carburetted hydrogen gas, cyanogen, or gaseous ammonia generated in the
same retort with the carburetted hydrogen, or from salts containing such gases
placed in the converting vessel or chamber.
Having thus described our improvements, and means which we adopt in
carrying the same into effect, we would have understood that what we claim
is, when converting wrought or malleable iron into steel in a closed vessel or
chamber by the aid of carburetted hydrogen gas or other suitable converting
gas, or combinations thereof, the employment of a non-inflammable gas or a
gas only inflammable at a very intense heat, as a means of displacing the car-
buretting gas from such vessel or chamber previous to opening the same to
the atmosphere, substantially as explained.
Also we claim when converting wrought or malleable iron into steel in a closed
vessel or chamber by the aid of carburetted hydrogen gas, the obtaining the ex-
haustion of such gas from such vessels or chambers by lighting a jet thereof
as it is permitted to escape in regulated quantities whilst it is forced out by
atmospheric air, also admitted in regulated quantities, in manner substantially
as explained.
Also we claim the method of operating for re-charging such vessels or
chambers in manner substantially as explained.
In witness whereof, we, the said John Jobson and John Farmerley Dickson
have hereunto set our hands and seals, this 3rd day of January, in
the year of our Lord One thousand eight hundred and sixty-six.
JOHN JOBSON
170)