IMPROVEMENTS IN TREATING IRON FOR THE PURPOSE OF CON- VERTING IT INTO STEEL OR HARD METAL, AND FOR PLATING OR COATING AND HARDENING AND TEMPERING IRON AND STEEL
Year: 1866

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 TREATING IRON FOR THE PURPOSE OF CON-
VERTING IT INTO STEEL OR HARD METAL, AND FOR PLATING OR COATING AND
HARDENING AND TEMPERING IRON AND STEEL."-A communication from
abroad by Elliot Savage, of West Meriden, State of Connecticut, United
States of America.
Sealed the 19th October 1866, and dated the 25th July 1866.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition, on the
25th July 1866.
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 TREATING IRON FOR THE PURPOSE OF
CONVERTING IT INTO STEEL OR HARD METAL, AND FOR PLATING OR COATING AND
HARDENING AND TEMPERING IRON AND STEEL," to be as follows:-
This Invention relates to an improved method of treating iron for the
purpose of converting it into steel or hard metal, and for preserving iron and
steel from oxidation.

page_text: The Invention also relates to an improved method of hardening and
tempering iron and steel and of obtaining upon the surface of the same the
first film or deposit of the metal desired, as silver, copper, and gold, for the
purpose of coating or plating the same during the hardening process.
Any convenient quantity of cyanide of potassium is melted in a crucible and
brought to the temperature of, say, from five bundred to eight hundred
degrees Fahrenheit. The degree of hardness to be given to the metal will
depend upon the temperature of the molten mass in the crucible. The metal
either in a cold state or slightly heated is to be plunged into the melted
cyanide and allowed to remain until it has acquired the temperature of the bath.
It has been found that with some irons the required result may be obtained
in two hours, while other irons will require three or four hours. While the
iron is hot it is to be removed to a cooling bath consisting of a nearly saturated
solution of cyanide of potassium in water, to which is added a quantity of
some salt of silver, such as the chloride of silver, sufficient to bring up the
strength of both to about ten degrees Beaumé; but other cooling solutions
may be used. These solutions should by preference be prepared from the
chloride of the metal with which it is desired to coat or plate the iron or steel,
as such compound is free from acid and can be readily dissolved in a proper
fluid, but sulphates, such as the sulphates of copper and other metals, may be
used for the cooling solution. The metal after such treatment will be found
to possess a hard or steely character, and may be used for many of the
purposes for which steel is now employed.
In adapting the process for hardening, plating, or coating very fine articles,
such as engraved plates of steel, it is preferable to use a cooling solution pre-
pared from chloride of silver in the following manner :-Dissolve the chloride
of silver in a solution of cyanide of potassium in water or in solution of
ammonia. If the solution is to be of copper dissolve the chloride of copper
in water until the proper specific gravity (10° Beaumé) is obtained. In order
to simply harden the iron or steel it may be removed from the melted cyanide
of potassium as soon as it has been raised to the proper temperature; it
should then be suddenly plunged into the cooling liquid, and allowed to
remain therein until cool.
The above metallic solutions or their equivalents are necessary when it is
desired to plate the steel, but when the object is simply to harden the steel
any ordinary cooling liquid may be used, although the best results will be
obtained with the solutions first described. While the metal is in the cyanide
bath the adhering portion of the melted cyanide will be dissolved off by the
solution, and as the iron or steel will be hot the first particles of the metal

page_text: which are deposited will penetrate the pores of the iron or steel and at the
surface will form an actual alloy.
The haloid salts of the metals are preferable for the cooling bath as those
contain no acids, but the oxysalts may be employed if the acid contained
therein be neutralized.
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 24th January 1867.
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 Twenty-fifth day of July, in the year of our Lord
One thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said.
William Edward Newton, Her special licence 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
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN TREATING IRON FOR THE PURPOSE OF CONVERTING IT INTO
STEEL OR HARD METAL, AND FOR PLATING OR COATING AND HARDENING AND
TEMPERING IRON AND STEEL," being a communication from Elliot Savage, of.
West Meriden, State of Connecticut, United States of America, upon the,
condition (amongst others) that I, the said William Edward Newton, my
executors or administrators, by an instrument in writing under my, or their,.
or one of their hands and seals, 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 Willium Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same is

page_text: to be performed, to be particularly described and ascertained in and by the
following statement (that is to say):-
This Invention relates to an improved method of treating iron for the
purpose of converting it into steel or hard metal, and for preserving iron and
steel from oxidation.
The Invention also relates to an improved method of hardening and
tempering iron and steel, and of obtaining upon the surface of the same the
first film or deposit of the metal desired, as silver, copper, and gold, for the
purpose of coating or plating the same during the hardening process.
The following is a description of the manner of carrying out the Invention
for the various purposes above mentioned:-A crucible or other suitable
vessel adapted to the size of the iron or steel to be operated upon is made
ready, and in this crucible is melted any convenient quantity of cyanide of
potassium, which is brought to the temperature of, say, from five hundred to
eight hundred degrees Fahrenheit. As a general rule the higher the tempe-
rature (within the limits above mentioned) to which the melted cyanide is
raised, either before the metal is plunged into it or while in it, the greater
will be the degree of hardness imparted to the metal after it has been after-
wards plunged into the cooling bath. I would remark that a great degree of
hardness will be given by the highest temperature above named. The metal
either in a cold state or slightly heated is to be plunged into the melted
cyanide and allowed to remain until it has acquired the temperature of the
bath. The length of time the iron should remain in the melted cyanide of
potassium depends in a great measure upon the quality of the iron and the
temperature of the bath. It has been found that with some irons the
required result may be obtained in two hours, while other irons will require
from three to four hours immersion. While the iron is hot it is to be
removed to a cooling bath consisting of a nearly saturated solution of cyanide of
potassium in water, and if it be intended to coat the iron with silver a quantity
of some salt of silver, such as the chloride of silver in proportions sufficient to
bring up the strength of the bath to about ten degrees Beaumé. Other
cooling solutions may however be substituted for the one above mentioned;
these solutions should by preference be prepared from the chloride of the
metal with which it is desired to coat or plate the iron or steel, as such com-
pound is free from acid and can be readily dissolved in a proper fluid.
Sulphates, such as the sulphates of copper and other metals, may however be
used for the cooling solution if desired. The metal after such treatment will
be found to possess a hard or steely character, and may be used for many of
the purposes
for which steel is now employed.

page_text: In adapting the process for hardening, plating, or coating very fine articles,
such as engraved plates of steel, it is preferable to use a cooling solution.
prepared from chloride of silver in the following manner:- Dissolve the.
chloride of silver in a solution of cyanide of potassium in water or in solution
of ammonia. The chloride solution should be of about the strength of
ten degrees of Baumé's hydrometer. I would observe, however, that.
by increasing the specific gravity. of the cooling solution the tempera-
ture at which the steel should be at the moment of immersion may be
lowered, and consequently the risk of change of shape or of fracture will,
be lessened accordingly. If the solution is to be of copper dissolve, the
chloride of copper in water until the proper specific gravity, ten degrees
Baumé, is obtained. In order to simply harden the iron or steel it may
be removed from the melted cyanide of potassium as soon as it has been.
raised to the proper temperature; it should then be suddenly plunged into the.
cooling liquid and allowed to remain therein until cool. The strength or
density of the cooling liquid required for different kinds of articles to be
hardened, and, the proper temperature to which the steel must be brought
before immersing it in the cooling solution in order to obtain the required
degree of bardness, can soon be determined by a few trials and a very little
experience. If the steel should be made too hard the temper can be reduced
by any of the usual methods.
The above metallic solutions or their equivalents are necessary when it is
desired to plate the steel, but when the object is simply to harden the steel
any ordinary cooling liquid may be used, although the best results will be
obtained with the solutions first described.
.
The metal may be removed from the cooling bath as soon as it is cool, and
will be found not only to be perfectly coated with a film of the metal held in
solution in the cooling bath, but to be hardened. The metal when taken
from the bath of melted cyanide of potassium will have enough of that
substance adhering to it to preserve it from the action of the oxygen of the
atmosphere while being removed to the cooling bath. While the metal is in
the cyanide bath the adhering portion of the melted cyanide will be dissolved
off by the solution, and as the iron or steel will be hot the first particles of
the metal held in solution which are deposited will penetrate the pores of the
iron or steel, and at the surface will form an actual alloy.
It will be obvious that for the salt of silver in the cooling bath the salt of
some other metal may be substituted, and that the hardening will in such
case take place in connection with the deposit of the coating of the metal held
in solution.

page_text: The haloid salts of the metals are preferable for the cooling bath, as
those contain no acids, but the oxysalts may be employed if the acid contained
therein be neutralized.
Having now described the Invention which has been communicated to me
by my foreign correspondent as aforesaid, and having explained the manner
of carrying the same into effect, I would remark that what I claim as new
in the Invention of "Improvements in Treating Iron for the Purpose of Con-
verting into Steel or Hard Metal, and for Plating or Coating Iron and Steel,
and Hardening and Tempering Iron and Steel," is,-
First, heating the metal by immersing it in a bath of melted cyanide of
potassium, as and for the purposes herein set forth.
Second, cooling the metal after it has been heated in a bath of melted cyanide
of potassium, by immersing the heated iron in a suitable cooling liquid, such as
a solution of cyanide of potassium, either alone or in combination with any
suitable metallic salt, as herein set forth.
In witness whereof; I, the said William Edward Newton, have hereunto
set my hand and seal, the Twenty-fourth day of January, in the year
of our Lord One thousand eight hundred and sixty-seven.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
W. E. NEWTON. (L.S.)