AN IMPROVEMENT IN THE MANUFACTURE OF CAST STEEL
Year: 1867

page_text: LETTERS PATENT to Robert Mushet, of Cheltenham, in the Connty of
Gloucester, Metallurgist, for the Invention of "AN IMPROVEMENT IN THE
MANUFACTURE OF CAST STEEL."
Sealed the 8th March 1867, and dated the 14th January 1867.
PROVISIONAL SPECIFICATION filed by the said Robert Musbet at the
Office of the Commissioners of Patents, with his Petition on the
14th January 1867.
I, ROBERT MUSHET, of Cheltenham, in the County of Gloucester, Metallurgist,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT IN
THE MANUFACTURE OF CAST STEEL," to be as follows:-
In the manufacture of cast steel by the ordinary process of melting either
steel or mixtures of materials which when melted produce cast steel it is
customary to add to the steel or mixture of steel-producing materials
constituting the charge of each melting pot or crucible a few ounces of
peroxide of manganese as a flux, which likewise improves the tenacity and
ductility of the cast steel produced when heated and forged, and materially
increases the capability of the said cast steel to bear a high degree of heat
when being forged or rolled.
My Invention consists in employing as a flux in place of peroxide of
manganese chromate of iron, oxide of chrome, or an artificial mixture of
chrome oxide and oxide of iron, but as chromate of iron answers perfectly
for my process, and is far cheaper than chrome oxide or artificial mixtures of
chrome oxide and oxide of iron, I prefer to use the chromate of iron.

page_text: Chromate of iron is a material found abundantly in nature, and consisting
essentially of the oxides of chrome and iron. The chromate of iron which
I prefer to employ is that which is most free from gangue, veinstone, and
likewise sulphur and phosphorus, which are sometimes found associated with
chromate of iron. I prepare the chromate of iron for my process by
pulverising it, or by breaking it into small pieces. To the charge of steel,
or of steel-producing materials which it is intended to melt into cast steel,
and which charge of steel or steel-producing materials usually amounts to
from forty to fifty pounds avoirdupois for each melting pot more or less, I add
from three to six ounces of chromate of iron, but I do not confine myself to
these specific quantities of chromate of iron, for these quantities may be varied
without departing from the nature of my Invention; I introduce the chromate
of iron into the melting pot along with the charge of steel or of steel-producing
materials which it is intended to melt into cast steel, and for the sake of
convenience I wrap the said chromate of iron in a piece of paper and drop
it into the melting pot along with the steel or steel-producing materials.
The chromate of iron may nevertheless be introduced into the melting pot at a
subsequent stage of the melting operation, but I find it convenient to introduce
it along with the steel or steel-producing materials intended to be melted into
cast steel. When the steel or the mixture of steel-producing materials is
melted I withdraw the melting pots from the melting furnace and pour the
steel into ingot moulds or other suitable moulds in the usual manner. I do
not employ oxide of manganese or any flux in my process, except chromate of
iron as other fluxes are not essential to the success of my process. The
essence of my Invention consists in the use of chromate of iron as a flux in
place of peroxide of manganese in the ordinary process of manufacturing
cast steel by melting in crucibles or melting pots steel or any mixture of
materials which when melted produce cast steel with the addition or together
with chromate of iron in order thereby to improve the quality of the cast
steel produced. My process of manufacturing steel not only increases the
ductility and tenacity of the cast steel when heated and forged, but it also
prevents or materially diminishes the shrinkage, or what is termed the "piping,"
of cast steel ingots, thus saving much waste. My process also renders the
bars of cast steel when forged from the ingots free or nearly free from seams,
technically ternied "kokes ;" and, lastly, cast steel prepared by my process is
wholly or nearly free from the defect of what is termed "water cracking"
when hardened.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Mushet in the Great Seal Patent Office on the
9th July 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MUSHET, of Cheltenham, in the County of Gloucester, Metallurgist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of January, in the year of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her reign.
did, for Herself, Her heirs and successors, give and grant unto me,. the said
Robert Mushet, Her special licence that I, the said Robert Musbet, my
executors, administrators,. and assigns, or such others as I, the said Robert
Mushet,. 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 "AN IMPROVEMENT IN THE MANU-
FACTURE OF CAST STEEL," upon the condition (amongst others) that I, the said.
Robert Musbet, 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 Robert Mushet, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say. :-
In the manufacture of cast steel by the ordinary process of melting either
blister steel or scrap steel, or mixtures of materials which when melted.
produce cast steel, it is customary to add to the steel or mixture of steel--
producing materials constituting the charge of each melting pot or crucible a
few ounces of peroxide of manganese as a flux. The said peroxide of
manganese acts as a flux, and likewise improves the tenacity and ductility of
the cast steel produced when heated and forged, and materially increases
the capability of the said cast steel to bear a high degree of heat without
cracking when being forged or rolled.

page_text: My Invention consists in employing as a flux in place of peroxide o
manganese, chromate of iron, oxide of chrome, or an artificial mixture o
chrome oxide and oxide of iron, but as natural chromate of iron answers
perfectly for my process, and is far cheaper than chrome oxide or artificial
mixtures of chrome oxide and oxide of iron, I prefer to use the natural
chromate of iron. Chromate of iron is a mineral found abundantly in nature,
and consisting essentially of the oxides of chrome and iron. The chromate of
iron which I prefer to employ is that which is most free from gangue,
veinstone, and likewise free from sulphur and phosphorus, which latter are
sometimes found associated with chromate of iron. I prepare the chromate
of iron for my process by pulverising it, or by breaking it into small pieces;
or I make use of it in the granulated state in which it is frequently found in
To the charge of steel or of steel-producing materials which it is
intended to melt into cast steel, and which charge of steel or steel-producing
materials usually amounts to from forty to fifty pounds averdupois for each
melting pot more or less, I add from three to six ounces of chromate of iron,
but I do not confine myself to the specific quantities of chromate of iron; for the
quantities may be varied without departing from the nature of my Invention.
I introduce the chromate of iron into the melting pot along with the charge
of steel or of steel-producing materials which it is intended to melt into cast
steel, and for the sake of convenience I wrap the said chromate of iron in a
piece of paper, and drop it into the melting pot along with the steel or
mixture of steel-producing materials. The chromate of iron may nevertheless
be introduced into the melting pot subsequently to the introduction and
melting or partially melting of the steel or steel-producing materials, but I find
it convenient to introduce the said chromate of iron along with the steel or steel-
producing materials intended to be melted into cast steel. When the steel or
the mixture of steel-producing materials and chromate of iron are melted into
cast steel I withdraw the melting pots from the melting furnace, and pour
the said cast steel into ingot moulds or other suitable moulds in the usual
manner. .
O 02.
Introduce these materials into a melting pot, and when the steel is melted 35
withdraw the melting pot and pour the melted steel into an ingot mould.

page_text: Spiegel cisen
Chromate of iron pulverised
And proceed as in Example No. 1.
EXAMPLE No. 3.
Take hard converted bars -
Chromate of iron -
And proceed as in Example No. 1.
-
2 lbs. or 3 lbs.
6 oz.
- 40 lbs.
.. 6 oz.
It is not necessary to employ oxide of manganese or any other flux in my
process, except chromate of iron, these other fluxes not being essential to the
success of my process. They may, however, be occasionally used without any
injurious effect. My process not only increases the ductility and tenacity of
the cast steel produced by it when the said cast steel is heated and forged, but
it also prevents or materially diminishes the shrinkage, or what is termed the
piping," of the cast steel ingots, thus saving much waste. The bars of steel,
also which are forged from ingots of cast steel produced by my process are
(when the cast steel has been thoroughly melted in a workmanlike manner)
free or nearly free from those serious imperfections technically called "rokes"
or seams; and, lastly, cast steel prepared by my process is wholly or nearly
free from the defect of what is termed "water cracking" when hardened.
The essence of my Invention consists in the use of chromate of iron as a
flux in place of or in addition to peroxide of manganese or other flux in the
ordinary process of manufacturing cast steel, that is, by melting in crucibles or
melting pots blister steel, scrap steel, or any mixture of materials which when
melted produce cast steel, with the addition of or together with chromate of
iron, in order thereby to improve the quality of the cast steel produced.
In witness whereof, I, the said Robert Mushet, have hereunto set my
hand and seal, this Fifth day of July, in the year. of our Lord One
thousand eight hundred and sixty-seven.
Witness,
LISOWNA M. MUSHET,
Cheltenham.
ROBT. MUSHET. (L.S.)