IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1885

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co Patent Agents,
Southampton Buildings in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS IN THE MANUFACTURE OF STEEL" to be as
follows:
This invention relates to the manufacture of steel termed "French metal" from
carburised iron or steel in either a solid or melted condition, which is acted upon
necessarily by oxygen and hydrogen, or by water-steam. The oxygen has the
effect of eliminating the carbon and the other metalloids, whilst the hydrogen
acting subsequently upon the metal reduces the oxide of iron which has been
formed by the oxidation caused by the oxygen.
The carburised metal, either cast iron or steel, upon which the successive
currents of oxygen and hydrogen are to act can be melted in a retort, reverberatory
furnace, converter or the like, and therein subjected to the action of pure oxygen
and of hydrogen; or the cast iron or steel can be melted in a high furnace, a cupola
or a converter, and thence flow, or be poured, into the apparatus in which it is to
be subjected to the successive action of oxygen and hydrogen; or the treatment
with oxygen and hydrogen can take place in the Bessemer converter itself before
the tapping of the metal. Solid metal heated to 700 or 800 degrees Centigrade can
also be operated upon.
Whatever mode of operation is employed, the successive currents of pure oxygen
and hydrogen can be replaced by a current of water-steam which is decomposed by"
the high temperature of the metal into its two elements of oxygen and hydrogen.
After the treatment with oxygen and hydrogen, the metal is heated to 700
or 800 degrees and hardened in a bath composed of water, azotic acid, soda-salt and
common salt.
The distinctive features of this process will be easily understood by the
description of the various modes of operation which can be applied. According to
the first mode of operation the ferrous metal, such as cast iron or steel, is placed in
a hermetically closed retort and heated to about from 800 to 900 degrees
Centigrade, pure oxygen being then injected into the said retort. The action

page_text: which takes place is the following: Each atom of carbon having a very great
⚫ affinity for oxygen combines with two atoms of the latter and separates from the
metal in order to form carbonic acid which escapes through a bent tube connected
to the retort and dipping into water. This action of the oxygen upon the carbon
continues until the carbon has completely disappeared. The carbon then enters
into combination with the metalloids remaining in the metal according to the degree
of affinity which they have for oxygen, and will progressively attack them until all
have completely disappeared. The operation is then stopped and the retort is opened,
the metal produced being decarburized and free from any metalloid. As, however,
the metal contains infinitesimal traces of oxide which might be injurious to the
quality of the metal, they are removed by dry and pure hydrogen. I employ
hydrogen, not only for removing the traces of oxide, but because this gas, by acting
for a certain time upon this metal, causes the molecules of the same to combine
very closely, and hardens them so that the homogeneousness is complete.
The metal produced by the operation above described is decarburised, pure,
refined and homogeneous.
According to the second mode of operation the ferrous metal is melted in a
retort, or reverberatory or other furnace, or converter, or it is previously melted
before being placed therein. I then, by means of blast-pipes provided with a very
great number of jets, inject pure oxygen, gently at first, so as not to crack (étonner)
or burn the lower part of the melted metal. As the pressure of the gas is gradually
augmented ebullition commences and becomes very intense, a bright orange flame
rising from the metal, which flame becomes whiter and then sinks. At this
moment (which can be ascertained by means of the spectroscope) the metalloids
baving disappeared, I place blast pipes in communication with the converter,
through which pipes, provided with a great number of jets, dry and pure hydrogen
is admitted. By means of the hydrogen the destruction of the traces of oxide is
effected instantaneously. The operator, by means of tests made with the fused-
metal immediately judges of the quality of the metal and of its hardness or
homogeneousness. In order to obtain a perfect metal, which is elastic, and hard,
and does not readily become heated, and which is especially suitable for purposes
of artillery, one or two per cent of chromium can be added a little before the
introduction of hydrogen.
According to a third mode of operation I can replace the pure oxygen and the
dry and pure hydrogen used in the two modes of operation which I have described,
by the decomposition of very dry water-steam. I cause a current of water-steam to
pass into the retort, furnace, or converter, containing the solid or melted metal; the
steam is thereby decomposed into its elements of oxygen and hydrogen; the
metalloids, according to the law of affinities, combining with the atoms of oxygen,
whilst the free hydrogen passes into a gas-holder whence it is, after having been
dried, subsequently conveyed into the retort, furnace or converter.
The fourth mode of operation which can be employed does not offer any
difficulties, and facilitates the general operation. According to this mode I simul-
taneously introduce into the retort containing the solid or melted metal, oxygen
and hydrogen heated above 150 degrees Centigrade. The operation commences
gently at first and increases progressively, as with the means hereinbefore described,
and lasts only fifteen minutes for the fusion; dry and pure hydrogen is then
introduced so as to destroy the traces of oxide, and to harden the metal.
With the fifth mode of operation I commence only at the moment when, in the
operation of the manufacture of Bessemer steel, the metal is run either into flasks
(lingotières) or into moulds; at this moment I inject oxygen, gently at first, and
gradually increasing the pressure until the spectroscope indicates that the carbon
and the metalloids have disappeared. When this is the case I immediately
introduce dry and pure hydrogen at an intense pressure, in such a manner that the
Decessary time is allowed for producing an effect, while the metal contained in the
converter is quite liquid and not pasty. A little prior to introducing the bydrogen,
chromium can be added; this however is not absolutely necessary. The action of

page_text: the hydrogen upon the traces of oxide contained in the metal is almost immediate.
If the hardness and the homogeneousness of the metal is to be increased, that is to
say if a product is to be obtained the grain of which is extremely fine, it is
necessary to maintain the metal in a state of fusion, for this purpose a slight
quantity of oxygen may be injected in order to maintain the heat, after which the
injection of hydrogen may be commenced again; but the injection of oxygen must
be extremely slight so as not to injure the product.
This second injection of oxygen may be dispensed with, by placing under the
converter, which is completely fixed in this operation, a furnace charged with
incandescent fuel this furnace being placed upon a wagon.
When, by the action of the bydrogen, the hardness and fineness of the grain
which is desired is obtained, tho metal is run into flasks or moulds.
Whatever mode of operation is employed, I can use, instead of pure oxygen,
purified atmospheric air; for this purpose I compress air in a receptacle in which
charcoal containing potash (charbon potasse) which has the property of absorbing
azote is placed. Before introducing this purified air into the retort, I cause it to
pass through tubes according to the process of Dumas and Boussingault; I mix it
afterwards with pure oxygen, produced by known means, or with ozone.
operation takes a little longer but gives complete results.
The
After leaving the retort, the metal heated to 700 or 800 degrees, or the metal
cooled down to this temperature is immersed in a bath composed as follows; pure
water, azotic acid in the proportion of one fourth, soda-salt, and common salt; the
quantity of salt must not exceed 100 grammes for 10 litres of water.
The duration of the immersion in this bath must be sufficient for the metal
to cool.
The refined metal being removed from this bath is re-heated, then hammered or
rolled, and finally hardened in pure cold water. This hardening is in some respects
a cementation combined with hardening.
DIL OL
T 1005
HASELTINE, LAKE & Co.,
For the Applicant.

page_text: The bath being prepared, the metal to be treated is heated to Cherry-red (700°
to 800°) in an oven or furnace, and is then plunged into the bath prepared as
described. The volume of liquid in the bath should exceed the volume of the metal
ten times.
When placed in the bath the metal is allowed to remain until completely cool,
which cooling requires a variable time according to the mass of metal treated.
The metal when converted into steel, is hammered and subjected to the action of
cold water; it is then ready to be brought into commerce, and it is malleable, and
capable of being welded and of receiving a temper.
The bath above mentioned can be used indefinitely, the only requirement being
to add water, acid, and salts thereto in the proportions suitable for the metal to be
treated in order to maintain the above indicated proportion between the volume
of the bath and that of the metal.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is,
First. The production of steel by the immersion of more or less carburetted iron
(especially Bessemer, Martin Siemens and other analogous metals) at a red heat
into a bath composed of water, azotic or nitric acid, Carbonate of soda and Chloride
of Sodium; which immersion in the said bath constitutes a wet process of refining
or purifying and cementation combined substantially as described, for the purpose
specified.
Second. A bath composed of water, azotic or nitric acid, Carbonate of soda and
Chloride of Sodium, substantially as, and for the purpose described.
HASELTINE, LAKE & Co.,
For the Applicant.