IMPROVEMENTS RELATING TO THE CONVERSION OF IRON INTO STEEL AND TO APPARATUS THEREFOR."
Year: 1876

page_text: "
LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake,
& Co., Patent Agents, Southampton Buildings, London, for the Invention of
IMPROVEMENTS RELATING TO THE CONVERSION OF IRON INTO STEEL AND TO
APPARATUS THEREFOR." A communication from abroad by Count Guillaume
Ferdinand de Douhet, of Paris, France, Senator.
Sealed the 28th July 1876, and dated the 2nd February 1870.
PROVISIONAL SPECIFICATION left by the said William Robert Lake at 'the
Office of the Commissioners of Patents on the 2nd February 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS RELATING TO THE CONVERSION
OF IRON INTO STEEL AND TO APPARATUS THEREFOR." A communication.
This Invention relates to processes whose objects are the utilizing of the
carbonization of peat, and of the agglomerations made by means of pitch or tar
(except coal) for the purpose of cementing or converting into steel at a low tem-
perature and in a few hours ordinary soft iron roll laminated, forged, or in scrap,
according to a method of cementation entirely novel.
The business of carbonizing peat is day by day increasing. It furnishes an
excellent fuel that for all purposes is more and more used as a substitute for
charcoal, to which it is greatly superior with regard to cheapness and calorific
power.
The greater number of manufacturers who devote themselves to this carbonization
are so anxious to obtain rapidly and easily this valuable combustible, that instead
of collecting the chemical sub-products with which the distillation or carbonization
of the peat would furnish them abundantly in closed vessels, they prefer to abandon
them limiting themselves generally to the retention simply of the ammonia by an
elementary treatment of peaty vapour in a vat with a suitable quantity of
sulphuric acid. But with regard to those light tarry matters such as paraffine and
volatile and heavy oils almost fit for lubrication but requiring careful extraction,
the manufacturers neglect them, preferring to lose then in the atmosphere in
carrying on the carbonization in a very crude manner, that is to say, in furnaces
sufficiently open to permit the ready escape of the peaty vapours, and bring about
the carbonization by the simple movement of the incandescent matter in vessels more
or less closed. But though it has been hitherto considered of but slight utility to
[Price 4d1

page_text: collect the sub-products of the carbonization of the peat, it however becomes
desirable not to lose them if they can be made to serve in the state of vapour and
gas superheated to the degree usually allowed by this carbonization for new and
important applications.
It has long been known that if soft iron heated to a bright red colour is immersed
in a solution of ferrocyanide of potassium it immediately acquires the hardness of
steel. The same phenomenon is observed in passing the crystals of this salt over
the surface of white hot iron, nevertheless this "steelification," for it is one, only
exists at the surface of the metal, but it is none the less true that it will transform
the iron into veritable steel if it is caused to enter ultimately into its molecular
constitution. A stcelification of the same kind is obtained by submitting iron at a
white heat to a current of carbonated hydrogen and ammonia, which moreover
but for the hydrogen would reproduce the two elements of cyanogen.
It is not necessary to describe herein the divers processes of steelification either
by the decarburization of cast iron, or the numerous methods tried lately in the
laboratory or factory. It is sufficient to understand that in the existing state of
the manufacture of steel, there is in the diverse definitions of this product such
confusion that it may be said each manufacturer possesses his own particular
cement which is always superior to that of his neighbour, and that one single truth
is apparent in this chaos, namely, that steel is only soft iron hardened, for which
hardening there are many processes all of which tend to cause the absorption by the
iron of a tenth part of its weight of carbon, a hardening however only manifest in
the tempering which then renders the metal proof against the action of a file.
Be that as it may it is certain that vapour of peat contains in abundance at the
moment of its distillation in closed vessels, or if, its carbonization in vessels more
or less closed carbonized hydrogen, ammonial gas; and peculiar volatile and
lubricating principles essentially adapted to serve as a vehicle for the assimilation
by the iron of the desired quantity of carbon. If I submit to the action of these
divers agents and to a temperature relatively low ordinary soft iron in bars of
varfous sizes I obtain in a few hours a steelification constant and sufficient to
transform this iron into commercial steel.
The novelty of this process does not therefore consist as will be seen in the
cementation of the iron by the action of the gas and chemical agents above
specified; neither would there be any novelty if the cementation of the iron
followed the usual process.
This process comprises a calcination in closed vessels in refractory boxes of bars
of iron mingled with charcoal hermetically sealed, and subjected during a long and
sustained action for a number of days in special furnaces heated to a very high
temperature, an operation naturally long, costly, and not in any respect resembling
my process. In the latter the cementation of the iron takes place simply in the
middle of peat, carbonizing itself in ordinary furnaces for producing its special
charcoal.
All the ordinary furnaces employed in the carbonization of peat are therefore
good and sufficient for this transformation of iron into steel, such as muffles
arranged contiguous to each other and in stages or open furnaces, which may be
closed when the carbonization appears sufficient or those that close themselves
gradually or effect the carbonization of the peat by a continuous movement and
all furnaces employed in peat works. The iron cemented in this manner furnishes
an excellent steel suitable for all uses, and a peculiar feature of this Invention is
the obtaining of this result at a low temperature by the above described processes.
Another feature is the cementation of iron in closed vessels by the dust of the
ordinary agglomeration of Paris charcoal or of green peat with the addition in
variable proportions, according to the rapidity of the effect to be obtained of
yellow or red prussiate of potash in powder, ferrocyanide and cyano ferrite of
potassium. In this case the cementation may be effected in closed vessels or boxes
such as are ordinarily used for the cementation of iron.
All the directions above given are applicable naturally to the steelifying (that is

page_text: Into Steel of iron by the carbonization of agglomerations
made by means of tar or pitch. It is casy in fact to understand that instead of
peat I may employ these agglomerations at the moment of their carbonization for
producing effects of steelifying nearly equivalent.
"
In applying the method above indicated it is apparent that among the furnaces
for carbonizing that used in the manufacture of artificial charcoal called Paris
charcoal" affords certain advantages. In fact when the moulded charcoal, still wet
with its tar or pitch, is introduced into the inuffles contiguous to and arranged one
above the other, as in these furnaces it is easy to place therein bars of soft iron of
the length of the setting boxes in the middle of the bricks or cylinders of moulded
charcoal, so that with a single operation I may have when the muffle is charged a
quantity of iron to steelify proportionate to that of the charcoal to harden and
carbonize by the firing of the muffle, which eliminates the tar in reducing the
same to the state of combustion by the hardening of the mass. When after-
wards the operation is finished, and the whole of the charge is deposited in the
extinguishing pans, the iron bars follow the movement, and remain till cool in
the same extinguishing pans or presence of the incandescent charcoal, extinguishing
themselves gradually, and permitting the iron to be penetrated very perceptibly
with the agents, whereby it is brought to the condition of steel. If, on the contrary,
it is desired to effect the carbonization of peat in the same furnace bars of iron
may be placed nearly the entire length of the muffle, taking care to first cover its
hearth with a layer of green peat. The iron in this state should be placed with
the bars side by side flatwise, or better still edgewise if the bars can be held in this
position, taking care that at the side of the door from which they should be taken
the ends of the bars project over the peat sufficiently to allow them to be first raised
with tongs before taking out the contents of the furnace. This done the furnace
is discharged, and I then re-charge quickly the hearth of the furnace, as above
described, placing in the same manner the bars still red in the middle of the fresh
peat; and in this manner I obtain by numerous successive operations, according
to the thickness of bars, a very good steel, which if it is immediately hammered
and refined equals in value the steels of Germany with regard to its facility in
forging and welding, while in its rough condition, as it comes from the furnace,
it may be employed directly for all the uses of steel, as for files, blacksmiths' work,
cutlery, and the like. The arrangement of furnaces with closed neck cylinders or
closed vessels for the purpose of collecting the sub-products of peat would probably
be still better if it were possible to withdraw therefrom the bars, and to renew
the charge of peat as easily as in the process above described. Nevertheless,
though this arrangement may be an excellent one, perhaps the first is preferable.
I employ an apparatus for placing the bars, and keeping them edgewise and side
by side in such a manner that they will not be reversed during their conversion
into steel. This apparatus is composed of two strong iron bars of a length equal
to the width of the muffle. These bars have notches sufficiently wide and deep to
hold edgewise the iron placed therein for conversion into steel. One of these large
bars is placed at the entrance of the furnace, and serves to support the iron. The
other is arranged at two-thirds the length of the muffle to sustain rigidly by means
of corresponding notches the iron bars, which are thus placed longitudinally edge-
wise, and side by side. Thus constructed the said apparatus forms a species of
grate with moveable bars, and which is placed immediately over the hearth of the
furnace.
The said apparatus is left in the muffle during the time necessary for the
steelifying to take place. The steel resulting from the employment of this
apparatus is perhaps more equal in its constitution than other steel.
If it is desired to steelify the scrap and ends of iron, which in the trade are some-
times termed ribbons, they may be thrown into the muffle in the middle of the
charge, and then emptied into the extinguishing pan till the mass is cool, then at
the moment of the sifting of the peat the iron in fragments is very easily separated

page_text: therefrom to be submitted to such calcination as is necessary to convert it into
steel by means of fresh charges of peat to be carbonized in the same muffles.
It is unnecessary to say that these fragments of iron thus converted into steel
cannot be utilized except as cast, steel.
It will be obvious from the above description that whatever may be the furnace
used for carbonizing the peat the object of this Invention is the conversion of iron
into steel by utilizing the carbonization of peat, and any combustible matter
agglomerated by means of tar or pitch, which conversion into, steel is effected at a
much lower temperature, and in a much shorter time than has heretofore been
practicable.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Robert Lake in the Great Seal Patent Office on the 2nd
August 1870.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS RELATING TO THE CONVERSION
OF IRON INTO STEEL AND TO APPARATUS THEREFOR.' A communication from abroad
by Count Guillaume Ferdinand de Douhet, of Paris, France, Senator.
"
This Invention relates to processes whose objects are the utilization of peat, and
the manufacture of all its agglomerations by pitch or tar, except oil, for the purpose
of cementing or steelifying at a low temperature and in a few hours ordinary soft
iron drawn, laminated, forged, or in scrap, according to a novel method of
cementation.
The business of carbonizing peat is day by day increasing; it furnishes an
excellent coal that for all purposes is more and more frequently used in place of
charcoal, to which it is greatly superior with regard to cheapness and calorific
power.
The greater number of manufacturers who devote themselves to this carbonization
are so axious to obtain rapidly and easily this valuable combustible that instead of
collecting the chemical sub-products with which the distillation or carbonization of
the peat would furnish them abundantly in closed vessels they prefer to abandon
them, limiting themselves generally to the retention simply of the ammonia by an
elementary treatment of peaty vapour in a vat with a suitable quantity of sulphuric
acid; but with regard to those light tarry matters, such as paraffine and volatile and
heavy oils almost fit for lubrication, but requiring careful extraction, the manu-
facturers neglect them, preferring to lose them in the atmosphere in carrying on the
carbonization in a very simple manner, that is to say, in furnaces sufficiently open
to permit the ready escape of the peaty vapours and bring about the carbonization
by the simple movement of the incandescent matter in vessels more or less closed.
But though it has been hitherto considered of but slight utility to collect the sub-
products of the carbonization of the peat, it however becomes desirable not to lose
them if they can be made to serve in the state of vapour and gas superheated to
the degree usually allowed by this carbonization for new and important applications.
It has long been known that if soft iron heated to a bright red color is immersed
in a solution of ferrocyanide of potassium it immediately acquires the hardness of
steel. The same phenomenon is observed in passing the crystals of this salt over
the surface of white-hot iron; nevertheless, this conversion into steel or "steeling,"
for it is one, only exists at the surface of the metal, but it is none the less true that
it will transform the iron into veritable steel if it is caused to enter intimately into
its molecular constitution. A steeling of the same kind is obtained by submitting
iron at a white heat to a current of carbonated hydrogen and ammonia, thereby
obtaining in addition to the hydrogen the two elements of cyanogen.
It is not necessary to describe herein the divers processes of steeling, either by the
decarburization of cast iron, or the numerous methods used lately in the laboratory
or factory. It is sufficient to understand that in the existing state of the manufacture

page_text: the diverse denmitions of this product such confusion that it may
be said each manufacturer possesses his own particular cement, which is always
superior to that of his neighbour, and that one single truth is apparent in this chaos,
namely, that steel is only soft iron hardened, for which hardening there are many
processes, all of which tend to cause the absorption by the iron of a tenth part of its
weight of carbon, a hardening however only manifest in the tempering, which then
renders the metal proof against the action of a file. Be that as it may it is certain
that vapour of peat contains in abundance at the moment of its distillation in closed
vessels, or of its carbonization in vessels more or less closed, carbonized hydrogen,
ammoniacal gas, and peculiar volatile and lubricating principles essentially adapted
to serve as a vehicle for the assimilation by the iron of the desired quantity of
carbon. If I submit to the action of these divers agents and to a temperature
relatively low, such as that of a carbonizing furnace ordinary soft iron in bars of
various sizes I obtain more or less quickly, that is to say, in a few hours, a steeling
constant and sufficient to transform this iron into commercial steel.
The novelty of this process does not therefore consist, as will be seen; in the
cementation of the iron by the action of the gas and chemical agents above
specified; neither would there be any novelty if the cementation of the iron followed
the usual process.
This process comprises a calcination in closed vessels in refractory boxes of bars
of iron mingled with charcoal, hermetically sealed, and subjected during a long and
sustained action of a number of days in special furnaces heated to a very high
temperature, an operation naturally long, costly, and not in any respect resembling
my process. In the latter the cementation of the iron takes place simply in the
middle of peat, carbonizing itself in ordinary furnaces for producing its special
charcoal.
All the ordinary furnaces employed in the carbonization of peat are therefore
good and sufficient for this transformation of iron into steel, such as muffles arranged
contiguous to each other and in stages such as are employed in the manufacture of
all kinds of agglomerations, especially the prepared charcoal known as "charbon de
Paris;" also open furnaces, which may be closed when the carbonization appears
sufficient, or those that close themselves gradually, or effect the carbonization of the
peat by a continuous movement, and all furnaces employed in peat works where
this carbonization may be effected by placing iron bars in the peat at the moment
of their carbonization, thus producing the proper degree of steeling, provided the
operation is prolonged or renewed more or less according to the thickness of the
bars to be steeled by fresh layers of peat, continuing by their carbonization the
steeling of the same iron. The iron cemented in this manner furnishes an excellent
steel suitable for all uses, and a peculiar feature of this Invention is the obtaining
of this result at a low temperature by the above-described processes.
Another feature is the cementation of iron in closed vessels by the dust of the
ordinary agglomeration of "charbon de Paris," or of green peat with the addition
in variable proportions, according to the rapidity of the effect to be obtained, of
yellow or red prussiate of potash in powder (cyano-ferride and cyano-ferrite of
potassium). In this case the cementation may be effected in closed or tight vessels
or boxes such as are ordinarily used for the cementation of iron; this process, known
only in laboratories not having been yet practised commercially.
All the directions above given are applicable naturally to the steeling of iron by
the carbonization of agglomerations by means of tar or pitch. It is easy in fact to
understand that instead of peat I may employ these agglomerations at the moment
of their carbonization for producing a nearly equivalent steeling effect.
In applying the directions above indicated it is apparent that among the furnaces
for carbonizing, that used in the manufacture of artificial charcoal called "Paris
charcoal" affords certain advantages. In fact, when the moulded charcoal still wet
with its tar or pitch is introduced into the muffies contiguous to and arranged one
above the other, as in these furnaces it is easy to place therein bars of soft iron of
the length of the setting boxes in the middle of the bricks or cylinders of moulded

page_text: Charcoal, So What with a single operation I may have, when the mume is charged, a
quantity of iron to steelify proportionate to that of the charcoal to harden and
carbonize in their form by the setting on fire of the muffle, which eliminates the tar
in reducing the same to the state of combustion by the hardening of the mass.
When afterwards the operation is finished and the whole of the charge is deposited
in the extinguishing pans, the iron bars follow the movement and remain till cool
in the same extinguishing pans in presence of the incandescent charcoal, extinguish-
ing themselves, gradually permitting the iron to be penetrated very perceptibly
with the agents, whereby it is brought to the condition of steel. If on the
contrary it is desired to effect the carbonization of peat in the same furnace bars
of iron may be placed nearly the entire length of the muffle, taking care to first
cover its hearth with a layer of green peat. The iron in this state should be placed
with the bars side by side flatwise, or better still edgewise, if they can be held in
this position, taking care that at the side of the door from which they should be
taken that the end of the bars project over the peat sufficiently to allow them to
be first raised with tongs before taking out the contents of the furnace. This done
the furnace is discharged and the hearth of the furnace is quickly re-charged, as
above described, placing in the same manner the bars still red in the middle of the
fresh peat, and in this manner I obtain by numerous successive operations,
according to the thickness of the bars, a very good steel, which if it is immediately
hammered and refined equals in value the steels of Germany with regard to its
facility in forging and soldering, while in its rough condition as it comes from the
furnace it may be employed directly for all the uses of steel, as for files, blacksmith's
work, cutlery, and the like. The arrangement of furnaces with closed neck
cylinders or closed vessels for the purpose of collecting the sub-products of
peat would probably be still better if it were possible to withdraw therefrom the
bars and to renew the charge of peat as easily as in the process above described.
Nevertheless, though this arrangement may be an excellent one, perhaps the first
which has this advantage of adapting itself to the manufacture of "charbon de
Paris," thus utilizing the dust of the peat used for the preceeding carbonization is
preferable.
I employ an apparatus for placing the bars and keeping them edgewise and
side by side in such a manner that they will not be reversed during their conversion
into steel. This apparatus is composed of two strong iron bars of a length equal
to the width of the muffle. These bars have notches sufficiently wide and deep to
hold edgewise the iron placed therein for conversion into steel. One of these large
bars is placed at the entrance of the furnace, and serves to support the iron. The
other is arranged at two-thirds the length of the muffle to sustain rigidly by
means of corresponding notches the iron bars which are thus placed longitudinally
edgewise and side by side. Thus constructed the said apparatus forms a species of
grate with moveable bars, and which is placed immediately over the hearth of
the furnace.
The said apparatus is left in the muffle during the time necessary for the steeling
to take place, care being exercised that it may not be disturbed in depositing the
peat. But it is advantageous when thought proper to turn the bars after this
deposit so that each part to be steeled may be in turn covered by the entire thick-
ness of the peat which forms the new charge of the muffle.
The steel resulting from the employment of this apparatus is perhaps more cqual
in its constitution than other steel.
If it is desired to steel the scrap and ends of iron, which in the trade are some-
times termed ribbons, they may be thrown by shovelfulls into the muffle in the
middle of the charge, and then emptied into the extinguishing pan till the mass is
cool, then at the moment of the sifting of the peat the iron in fragments is very
easily separated therefrom to be submitted to such calcination as is necessary to
convert it into steel by means of fresh charges of peat to be carbonized in the
same muffles.
It is unnecessary to say that these fragments of iron thus converted into steel

page_text: cannot be utilized except as cast steel, nevertheless, when transformed in this
manner they are worth much more than their primitive value. The coal at the
moment of its carbonization, that is to say, when it becomes coke, whether in gas
retorts as used for the purposes of lighting towns, or in specially constructed
furnaces (without regard to retaining the gas) for producing the coke direct is as
suitable as peat, and the agglomerations for conveniently producing steel from
iron.
No special apparatus need be here described; it is sufficient to place either in
gas retorts where they are charged with coal, or in coke furnaces soft iron either
rolled, laminated in bars, or in picces, in order to transform it into steel either after
one calcination or several calcinations of coke, according to the thickness of the
iron to be transformed into steel the same process of producing steel applies also
to all agglomerations of coal and coke by tar or pitch, the iron placed with them
at the moment of their calcination to harden them becomes evenly and rapidly
transformed into good steel. It might be objected to this application of the car-
bonization of the coal, and of agglomerations that the iron would become changed
by the sulphurous matters contained in the coal, but experiments have shewn
to me that the greater part of the sulphur remains attached to the coke during
the carbonization of the coal, and that in all cases there is not a sufficiently free
liberation of sulphurous gas to alter the steel-producing action of the various hydro-
carburets and the ammoniacal principles contained in coal in such abundance.
This Invention also comprises the application of the carbonization of wood,
branches, sticks, or blocks, either in ovens or furnaces, in closed vessels or in heaps
in forests, to the production of steel from iron, the gaseous principles in presence
with carbon at the commencement of carbonization being favorable to the production
of steel from iron. I should however state, that the steel-producing power from
wood is variable, and that in order to effect it quickly it is preferable to use
resinous woods, such as are obtained from our coniferous trees, pines, firs, larches,
cedars, junipers, and the like, and for other countries mountain broom and furze,
but particularly the stems and fallen leaves of those plants containing heavy and
essential oils, but always carbonized in vessels or apparatus more or less closed.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it under-
stood that I claim,-
First. The conversion into steel or steeling of iron by the carbonization either
of peat or its agglomerations, or of coal or its agglomerations by means of pitch
or tar, or of ordinary or resinous woods, or by the carbonization of other com-
bustibles, which carbonization is effected either in furnaces or vessels more or less
closed, or in stacks or heaps, as above specified.
Second. An apparatus consisting of two parallel horizontal bars of iron for
holding rigidly in a parallel position and edgewise the bars of iron which are to
be steeled or converted into steel within the carbonizing apparatus as above
specified.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Second day of August, in the year of our Lord Ono
thousand eight bundued and coventyr aix
W. ROBT. LAKE. (L.S.)