IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND CAST IRON, AND THE MANUFACTURE OF A MIXED METAL
Year: 1865

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street, in
the City of London, Patent Agent, for the Invention of "IMPROVEMENTS
IN THE MANUFACTURE OF CAST STEEL AND CAST IRON, AND THE MANUFACTURE
OF A MIXED METAL." A communication from abroad by Emile Martin
and Pierre Emile Martin, of Paris, France.
Sealed the 13th February 1866, and dated the 18th August 1865.
PROVISIONAL SPECIFICATION leftbythesaid Richard Archibald Brooman
at the Office of the Commissioners of Patents, with his Petition, on
the 18th August 1865.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
Loudon, Patent Agent, do hereby declare the nature of the said Invention
for IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND CAST IRON, AND
THE MANUFACTURE OF A MIXED METAL," to be as follows:-
In this Invention the object has been the manufacture of certain metals in
a reverberatory furnace, and upon the principle of the fusion of iron ornatural
steel in a bath of cast iron, practical and industrial results have followed,
whereby new products of superior quality and relatively cheap are regularly

page_text: manufactured. For these processes of manufacturing special metals and their
application, the present application is made. The products are classed in
three kinds, which I term cast steel, cast iron, or soft steel which will not
temper, and mixed metal between cast steel and cast iron.
1st, cast steel. I make first puddled steel, purified as far as possible from
sulphur and phosphorus, as follows:-The puddler forms the body or sole of
burnt scrap iron, and the currents of air are charged with ores rich in oxides;
during the working he throws upon the metal, in the proportion of 3 parts
to 200 parts by weight of the metal, a flux composed of 2 parts of sea salt
and 1 part of manganese melted together; this flux raises the temperature
considerably, makes the black scum more liquid, and at the same time frees
the metal from sulphur and phosphorus, which pass into the scum. The
puddler stops the operation as soon as he finds that the metal sufficiently
decarbonized has passed into the state of steel. The puddled steel thus
obtained is rolled or hammered and cut into pieces of, say, from two to four
pounds weight, for use as hereafter explained. In a reverberatory furnace
heated by gas according to Siemen's method, and raised by it or any other
means to a continuous white heat, I place about 700 lbs. of cast iron in
pieces, each weighing about 4 lbs., and a bath of liquid cast iron at
a high temperature is obtained. Into this bath I introduce by degrees
pieces of the puddled cast steel produced as before described, in blocks of
from two to four pounds, until about two hundred pounds have been
added. Fifteen to twenty minutes suffice for the fusion of these 200 lbs.
in the bath, which should be gently stirred to effect a thorough mixture,
and should be maintained at the white heat; I then add a second charge
of 200 lbs. of puddled steel heated to white heat, and always by degrees;
after a third charge of steel has become fused in the bath I take off the
black oxydizing scum on the bath, and replace it by clear vitreous scum,
such as that from a wood-heated blast furnace, and add an equal weight
of siliceous sand. The scum preserves the bath from oxidation, while the
sand prevents the metal becoming short or brittle. I continue to add to the
bath the doses of 200 lbs. of blocks of puddled steel as before stated as fast
as their fusion will admit, for instance, 3,400 lbs. arising from 700 lbs. of cast
iron, 2,300 lbs. of puddled steel, and 400 lbs. of debris or pieces of steel from
previous fusions. At this stage the whole is stirred, the metal is tested by
portions drawn from the bath, and according to its quality Iadd from 40 lbs. to
100 lbs. of similar cast iron previously heated to white heat, which fixes the
exact grain of the cast steel. To raise the temperature of and purity the bath

page_text: at the end of the operation, if necessary, I introduce a flux of manganese and
sea salt and fluor spar melted together in the proportion of 2 parts by weight
of sea salt to 1 part of fluor spar. The metal stirred and brought to the
required degree of quality is run into moulds or ingots in the following
manner: The moulds or ingots are arranged round the circumference of a
turning platform, which by revolving successively presents each mould or
ingot to the tap hole of the furnace, so that the whole bath of 3,400 lbs. of
steel produced in the furnace runs successively and uninterruptedly into the
moulds, but the puddler stops the flow of the steel as soon as one mould is
full, and allows the flow to recommence as soon as the next mould has arrived
under the tap hole; or the bath may be run from the furnace into a vessel, and
from the vessel into the moulds or ingots through an orifice which is opened
and closed alternately. When the orifice becomes stopped up a second may be
formed at the side. For a reverberatory furnace of about 4,000 lbs. capacity
the duration of the operation is from 5 to 6 hours, which allows of two
successive fusions in 12 hours, and therefore of 24 fusions a week; it is, how-
ever, necessary to have two furnaces, as cach requires repair after 10 or 12
fusions. The waste is about 10 or 12 per cent., according to the nature of
the materials employed; the consumption of coal is about 33 bushels in 12
hours, but anchracite, lignite, peat, or other similar materials may be sub-
stituted. It is necessary to add about 33 bushels in 12 hours for the furnace
for reheating the pieces of cast iron and puddled steel before introducing them
into the bath. It will be found economical to heat the pieces in an appendage
to the reverberatory or puddling furnace. By retaining the proportions of
cast iron, and varying those of puddled steel, a softer steel suitable for springs
is obtained ; thus a semi-hard steel is obtained by taking 700 lbs. of cast iron
and adding successively in the bath 2,600 lbs. of puddled steel, and 400 lbs. of
debris from previous fusions. The proportions of cast iron and puddled steel
may be varied according to the nature of the caststeel to be obtained. All pure
steely cast irons, that is to say, those which give puddled steel of good quality,
will produce by this process good qualities of cast steel. Good cast-steel is like:
wise produced from natural irons and steels refined by wood. The manufac-
ture of cast steel may be carried on continuously if only part of the contents
of the bath be run out, and be replaced by an equal quantity of puddled steel.
The transformation of the cast iron into cast steel may take place directly after
For example, I run into an ingot, say
the transformation of the first bath.
a tenth of the contents of the bath of steel, and 1 replace it by an equal
quantity of steely cast iron in pieces heated to whiteness. This cast iron of

page_text: less density than the steel remains on the surface of the bath of a slight
thickness; I throw in powdered ore or any other oxidizing material which
extracts carbon from this thin layer of cast iron; I stir, and the assimilation
1
of the cast iron to the bath of cast steel is performed. The assimilation in
some cases may be obtained without the addition of an oxidizing material.
By withdrawing successively, say a tenth of the cast steel, and replacing it by
a corresponding quantity of steely cast iron, the process of transforming cast
iron directly into cast steel is continuous. Besides when the bath is
sufficiently deprived of carbon to allow of its beginning to coagulate and
pass to the state of iron, the addition of cast iron supplies enough carbon
to liquefy, and consequently assimilate the bath with the fresh charge of
cast iron.
2nd, cast iron or soft steel which will not temper.-For a fusion of
3,400 lbs. I employ 700 lbs. of steely cast iron, 2,600 lbs. of puddled granu-
lated iron (fer à grain), arising from the same cast iron, refined by the process
above described for puddled steel, for the manufacture of cast steel, and
100 lbs. of steel debris from the preceding fusions, adding melted fluor spar
with the flux employed during the work. I introduce into the bath at the
end of the fusion 20 to 40 lbs. of cast iron blocks ("fontes à facettes.") The
fusion is performed in the same manner aud in the same furnace as for the
cast steel, and it lasts the same time. The process differs only in the employ-
ment of granulated iron instead of puddled steel, and in the employment of
cast-iron blocks ("fontes a facettes.")
3rd, mixed metal or metal between cast steel and cast iron.-If in the
reverberatory furnace before-described I melt at white heat 1,000 lbs. of cast
iron, and if I introduce therein 200 lbs. of steel or iron in pieces at the same
temperature, the iron or steel melts rapidly in the bath of cast iron, and after
having stirred and removed the black scum, which I replace by clear scum, I
btain a mixed metal capable of being drawn while hot; this metal, which is
of equal grain, full and compact, very hard, malleable while hot, is less fragile
than cast iron. By increasing the proportion of iron introduced at white
heat into the bath of cast iron, the ductility of the metal is increased and its
fragility diminished.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Archibald Brooman in the Great Seal Patent
Office on the 17th February 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of August, 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
me, the said Richard Archibald Brooman, Her special licence that I, the said
Richard Archibald Brooman, my executors, administrators, and assigns, or
such others as I, the said Richard Archibald Brooman, my 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 Iuvention for "IMPROVEMENTS IN THE MANUFACTURE OF
CAST STEEL AND CAST IRON, AND THE MANUFACTURE OF A MIXED METAL," (commu-
nicated to me from abroad by Emile Martin and Pierre Emile Martin, of
Paris, France,) upon the condition (amongst others) that I, the said Richard
Archibald Brooman, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should par-
ticularly 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_imme-.
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Richard Archibald Brooman, do hereby
declare the nature of the said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement thereof, reference being had to the Drawings hereunto
annexed, that is to say :-
In this Invention the object has been the manufacture of certain metals in
a reverberatory furnace, and upon the principle of the fusion of iron or natural
steel in a bath of cast iron, practical and industrial results have followed,
whereby new products of superior quality and relatively cheap are regularly
manufactured. For these processes of manufacturing special metals and their
application the present application is made. The products are classed in three

page_text: kinds, which I term cast steel, cast iron, or soft steel, which will not temper,
and mixed metal, between cast steel and cast iron.
1st, cast steel. I make first puddled steel purified as far as possible from
sulphur and phosphorus as follows:-The puddler forms the body or sole of
burnt scrap iron, and the currents of air are charged with ores rich in oxides;
during the working he throws upon the metal, in about the proportion of
3 parts to 200 parts by weight of the metal, a flux composed of 2 parts of sea
salt and 1 part of manganese melted together; this flux raises the tempera-
ture considerably, makes the black scum more liquid, and at the same time
frees the metal from sulphur and phosphorus which pass into the scum. The
puddler stops the operation as soon as he finds that the metal sufficiently
decarbonized has passed into the state of steel. The puddled thus obtained
is rolled or hammered and cut into pieces of, say, from 2 to 4 pounds weight
for use as hereafter explained.
In a reverberatory furnace, such as that represented in Figure 1 of the
annexed Drawings, heated by gas according to Siemen's method, and raised by
it or any other means to a continuous white heat, I place about 700 lbs. of
cast iron in pieces, each weighing about 4 lbs. and a bath of liquid cast iron
at a high temperature is obtained; into this bath I introduce by degrees
pieces of the puddled cast steel produced as before described in blocks
of from 2 to 4 lbs., until about 200 lbs. have been added. 15 to 20
minutes suffice for the fusion of these 200 lbs. in the bath, which should be
gently stirred to effect a thorough mixture, and should be maintained at the
white heat; I then add a second charge of 200 lbs. of puddled steel heated
to white heat, and always by degrees; after a third charge of steel has become
fused in the bath I take off the black oxydizing scum on the bath and replace
it by clear vitreous scum, such as that from a wood heated blast furnace, and
add an equal weight of siliceous sand. The scum preserves the bath from
oxidation, while the sand prevents the metal becoming short or brittle. I
continue to add to the bath the doses of 200 lbs. of blocks of puddled steel
as before stated as fast as their fusion will admit, for instance, 3,400 lbs.
arising from 700 lbs. of cast iron., 2,300 lbs. of puddled steel, and 400 lbs. of
debris or pieces of steel from previous fusions. At this stage the whole is
stirred, the metal is tested by portions drawn from the bath, and according to
its quality I add from 40 lbs. to 100 lbs. of similar cast iron, previously heated
to white heat, which fixes the exact grain of the cast steel. To raise the
temperature of and purify the bath at the end of the operation, if necessary, I
introduce a flux of manganese and sea salt and fluor spar melted together, in
the proportion of 2 parts by weight of sea salt to 1 part of fluori
spar. The

page_text: metal stirred and brought to the required degree of quality is run into moulds
or ingots in the following manner:--The moulds or ingots are arranged round
the circumference of a turning platform, represented at A, Figure 2, which
by revolving successively presents each mould or ingot to the tap-hole of the
furnace, so that the whole bath of 3,400 lbs. of steel produced in the furnace
runs successively and uninterruptedly into the moulds, except that the puddler
stops the flow of the steel with a stopper B, Figure 3, as soon as one mould
is full, and allows the flow to recommence as soon as the next mould has
arrived under the tap hole; or the bath may be run from the furnace X,
(Figure 3) into a vessel C, Figure 4, and from the vessel into the moulds or
ingots round the platform A, through an orifice E, which is opened and
closed alternately by raising and lowering the stopper B on the end of the
movable rod G. When the orifice E becomes stopped up a second may be
formed at the side. For a reverberatory furnace of about 4,000 lbs. capacity
the duration of the operation is from 5 to 6 hours, which allows of two
successive fusions in 12 hours, and therefore of 24 fusions a week; it is
however necessary to have two furnaces, as each requires repair after 10 or 12
fusions. The waste is about 10 or 12 per cent., according to the nature of
the materials employed. The consumption of coal is about 33 bushels in
12 hours, but authracite, lignite, peat, or similar materials may be sub-
stituted. It is necessary to add about 33 bushels in 12 hours for the
furnace for reheating the pieces of cast iron and puddled steel before
introducing them into the bath. It will be found economical to heat
the pieces in an appendage to the reverberatory or puddling furnace. By
retaining the proportions of cast iron and varying those of puddled steel and
softer steel suitable for springs is obtained; thus a semi-hard steel is obtained
by taking 700 lbs. of cast iron, and adding successively in the bath 2,600 lbs.
of puddled steel and 400 lbs. of debris from previous fusions. The propor-
tions of cast iron and puddled steel may be varied according to the nature of
the cast steel to be obtained; all pure steely cast irons, that is to say, those
which give puddled steel of good quality, will produce by this process good
qualities of cast steel. Good cast steel is likewise produced from natural
irons and steels refined by wood. The manufacture of cast steel may be
carried on continuously if only part of the contents of the bath be run out,
and be replaced by an equal quantity of puddled steel. The transformation
of the cast iron into cast steel may take place directly after the transforma-
tion of the first bath. For example, I run into an ingot, say a tenth of the
contents of the bath of steel, and I replace it by an equal quantity of steely
cast iron in pieces heated to whiteness. This cast iron of less density than

page_text: the steel remains on the surface of the bath of a slight thickness; I throw in
powdered ore or any other oxidizing material which extracts carbon from this
thin layer of cast iron, I stir, and the assimilation of the cast iron to the
bath of cast steel is performed. The assimilation in some cases may be
obtained without the addition of an oxidizing material. By withdrawing
successively, say a tenth of the cast, steel, and replacing it by a corresponding
quantity of steely cast iron, the process of transforming cast iron directly
into cast steel is continuous; besides, when the bath is sufficiently deprived
of carbon to allow of its beginning to coagulate and pass to the state of iron,
the addition of cast iron supplies enough carbon to liquify and consequently
assimilate the bath with the fresh charge of cast iron.
2nd, cast iron or soft steel which will not temper.-Eor a fusion of
3,400 lbs. I employ 700 lbs. of steely cast iron, 2,600 lbs. of puddled
granulated iron (fer à grain), arising from the same cast iron, refined by the
process above described, for puddled steel, for the manufacture of cast steel,
and 100 lbs. of steel debris from the preceding fusions, adding melted fluor
spar with the flux employed during the work. I introduce into the bath at
the end of the fusion 20 to 40 lbs. of cast-iron blocks (fontes à facettes.)
The fusion is performed in the same manner and in the same furnace as for
the cast steel, and it lasts the same time. The process differs only in the
employment of granulated iron instead of puddled steel, and in the employ-
ment of cast-iron blocks (fontes à facettes).
3rd, mixed metal or metal between cast steel and cast iron.-If in the
reverberatory furnace before described I melt at white heat 1,000 lbs. of cast
iron, and if I introduce therein 200lbs. of steel or iron in pieces at the same tem-
perature, the iron or steel melts rapidly in the bath of cast iron, and after having
stirred and removed the black scum, which I replace by clear scum, I obtain a
mixed metal capable of being drawn while hot, this metal, which is of equal
grain, full and compact, very hard, malleable while hot, is less fragile than
cast iron. By increasing the proportion of iron introduced at white heat into
the bath of cast iron the ductility of the metal is increased and its fragility
diminished.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I claim,—
First, the manufacture of cast steel, of cast iron, or soft steel, and of a
mixed metal between cast steel and cast iron in a reverberatory furnace heated
to a high temperature by gas by processes or means based on the principle of
the fusion of iron or natural steel in a bath of cast iron, substantially as
herein-before described.

page_text: Second, running the metal in a state of fusion into moulds or ingots
arranged round the circumference of a turning platform, which in turning
presents the moulds or ingots successively to the tap hole, substantially as
herein-before described with reference to the accompanying Drawings.
In witness whereof, I, the said Richard Archibald Brooman, have here-
unto set my hand and seal, this Sixteenth day of February, One
thousand eight hundred and sixty-six.
R. A. BROOMAN. (L.S.)