IMPROVEMENTS IN THE PROCESS OF CEMENTATION
Year: 1861

page_text: LETTERS PATENT to William Edward Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE PROCESS OF CEMENTATION."-A com-
munication from abroad by Alexandre Lemaire, of Paris, in the Empire
of France.
Sealed the 22nd August 1861, and dated the 5th March 1861.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
5th March 1861.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE PROCESS OF CEMENTATION," to be
as follows:-
In the ordinary process of cementation as applied to the conversion of bar
iron into steel the operation is a long and tedious one, it being first necessary
to charge the cementing furnace or oven, then heat the same, and continue
the heat for a long time, and afterwards allow the oven to cool gradually
before withdrawing the charge. One of the objects of the present Invention
is to reduce the time necessary for the cementing operation, and also to
economise some of the ingredients employed in the process.
The improved process may be carried on in any of the ordinary cementation
furnaces now used, or apparatus specially adapted for the purpose may be
employed; and these furnaces or apparatus may be heated either by the waste

page_text: heat coming from other processes or operations, or furnaces may be constructed
for the purpose. The Invention or discovery consists in the employment in
the cementation process of a mixture of pulverized carbon and carbonate of
baryta or strontia, or other alkaline earthy carbonates. The apparatus,
whatever may be its form, is charged with a mixture of pulverized carbon and
powdered natural carbonate of baryta. A portion of the baryta may, if
desired, be replaced by an equivalent quantity of the carbonate of strontia.
The ends of the chambers or vessels in which the cementation takes place may
then be partially closed, and the whole heated to a red heat. When the
temperature appears sufficiently high one of the ends of the chamber is opened,
and the bars of iron are introduced into the middle of the cementing
ingredients, so that the bars may be completely covered with the mixture.
When the apparatus has been filled, the openings are closed. A bar may be
withdrawn from time to time and tested in the usual manner to ascertain how
the process progresses; and when the process is considered complete the bars
are all removed from the apparatus, taking care, however, to return into the
cementing chamber any of the cementing ingredients that may be drawn out
with the bars, and then the chamber may be again charged with fresh bars of
iron, adding from time to time a little of the cementing mixture, to com-
pensate for what may have become lost during the previous processes.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Edward Newton in the Great Seal Patent Office on
the 5th September 1861.
1
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the County.
of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fifth day of March, in the year. of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year. of
Her reign, did; for Herself, Her heirs and successors, give and grant unto me,
the said William Edward Newton, Her special license that I, the said William
Edward Newton, my executors, administrators, and assigns, or such others as
I, the said William Edward Newton, 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.

page_text: Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE PROCESS, OF CEMENTATION," being a communication from
abroad by Alexandre Lemaire, of Paris, upon the condition (amongst others)
that I, the said William Edward Newton, by an instrument in writing under
my hand and seal, 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 immediately after the date of the said Letters Patent.
NOW. KNOW YE, that I, the said William Edward Newton, 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 (that is to say):-
In the ordinary process of cementation of iron or steel the furnaces as at
present constructed for that purpose take a long while to become heated by
reason of their great size, and consequently take a long time to cool. Thus
an operation which with the ordinary cementing agents would require eight
days of cherry red heat, thrice that time would be required, because the
requisite temperature must first be attained, and then time allowed for perfect
cooling before withdrawing the cemented iron.
In order to effect the process of cementation by one continuous operation,
that is to say, in order not to be obliged to allow for the cooling and reheating
of the furnaces, the following is the method employed by the Inventor of the
present improvements:-The chambers or vessels in which the cementation
takes place may be of the ordinary construction, only they must be provided
at each extremity with an opening leading to the outside, and by which the
charging and discharging operations are effected. When in order to heat
these chambers the waste heat of reheating furnaces or furnaces for melting
steel is utilized, it will be preferable to employ a kind of retort made of
earthenware or of cast or wrought iron suitably protected against the flame,
and which may be placed either horizontally or vertically. The temperature
must always be such as will be above a red heat, and the process of cementa-
tion will be effected quicker in proportion as the temperature is higher.
In all these operations the cementing agents ordinarily employed have
merely a momentary action, as the salts which produce the cementation are
volatile. Thus salts of ammonia, soda, or potash, which are those most
commonly employed, are either volatile in themselves or decomposable at a red
heat by, charcoal, which converts them into equally volatile bodies; the
cyanides, which may be formed with the azote of the atmosphere, are also as
volatile, so that in a very short time the cementing agents will become

page_text: inoperative, and must be renewed. This is not the case if baryta or certain
of its salts are employed, the carbonate for example. When brought into
contact with charcoal at a red heat, this latter only gives baryta, which is a
body perfectly fixed at that temperature, or in admixture with the azote of the
air it is partially converted into cyanide of barium, which is considerably less
volatile than the cyanides of ammonium, sodium, and potassium.
In carrying out this Invention any suitable apparatus, chambers, or vessels
are to be charged with a mixture of powdered charcoal and native carbonate'
of baryta pulverized in the proportion of, at the most, fifty per cent. of
carbonate. (It is probable that experience will allow of the proportion of this
salt being diminished by one-half. Carbonate of strontia having the same
properties as this salt may also be employed in lieu thereof.)
The extremities' of the vessels in which the cementation is effected are to be
partially closed, and the whole is heated to a bright red heat. When the
temperature appears sufficiently high, one extremity of the chambers is opened,
and thin bars of iron are introduced into the midst of the cementing material,
so that they may be entirely covered by the mixture; when the chamber.is
full the opening is to be closed.
If it be desired to watch the progress of the cementation, one of the bars
under operation may be withdrawn and passed lightly through rolls; it is then
tempered and broken, and from the appearance of the grain it is impossible to
be deceived, so as not to obtain the exact degree of cementation required.
When the bars have reached the desired point they are to be withdrawn from
the chambers or vessels through the exterior opening, care being taken to
replace any of the cementing material which may fall outside during the
withdrawal of the bars of metal. When these bars have been all withdrawn
they are to be immediately replaced by other bars of iron, which are introduced
as easily as the first by reason of the friability of the cementing material, and
so on in succession. In this operation only a small quantity of charcoal is
employed, which may be always readily replaced. With regard to the car-
bonate of baryta it will last for almost any length of time, the azote of the air
which penetrates through the imperfectly closed openings, and even through
the chambers which are generally pervious to the atmosphere, is amply sufficient
for the formation of the substance intended to be employed for the cementation
of the iron.
By this process, therefore, the double advantage is gained of considerably
reducing the quantity of combustible hitherto employed for this operation, and
of using a very active cementing agent, which will last for almost any length of
time to which it is only necessary from time to time to add a small quantity
:

page_text: of charcoal, in order to supply the place of that which shall have been
burnt.
It is unnecessary to add that this cementing agent may be also employed in
the cementation furnaces now employed, and that it will even under these
circumstances effect great economy by reason of its energetic action and
unalterability.. The expense of the process of cementation being thus reduced,
it is reasonable to suppose that nearly all kinds or qualities of cast steel may
be obtained with cemented iron. The advantage would thus be gained of
obtaining steel of uniform hardness, as by this process the cementation may
be followed step by step, and stopped at the precise moment when thought
sufficient for a certain hardness of steel.
Having now described this Invention of "Improvements in the Process of
Cementation," and the manner of carrying the same into effect, as communi-
cated to me by my foreign correspondent, I desire it to be understood that
under the above in part recited Letters Patent, I claim, for the cementation of
iron or steel where the action of the furnaces is continuous, the employment of
alkaline carbonates, and particularly the carbonates of baryta and of strontia,
mixed with a certain quantity of powdered charcoal.
I also claim the employment of the carbonates of baryta and strontia in
other processes of cementation where the operation of the furnace is not
continuous, but where the process is carried on in ordinary furnaces, or in
steel melting crucibles, or in reverberatory furnaces. I desire it to be under-
stood that under the head of carbonates above mentioned, and of which I
claim the exclusive use, are included any other salts which, under the influence
of heat and in contact with carbon and the azote (nitrogen) of the atmosphere,
are capable of producing cyanides, which are in reality the cementing agents.
In witness whereof, I, the said William Edward Newton, have hereunto
set my hand and seal, the Fifth day of September, in the year of
our Lord One thousand eight hundred and sixty-one.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)