AN IMPROVEMENT OR IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL
Year: 1859

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of
Gloucester, Metallurgist, for the Invention of "AN IMPROVEMENT OR
IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL."
Sealed the 14th June 1859, and dated the 12th January 1859. .
PROVISIONAL SPECIFICATION left by the said Robert Mushet at the
Office of the Commissioners of Patents, with his Petition, on the
12th January 1859.
I, ROBERT MUSHET, of Coleford, in the County of Gloucester, Metallurgist,
do hereby declare the nature of the Invention for "AN IMPROVEMENT OR
IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL," to be as follows:-..
My Invention consists in alloying cast steel with the metal tungsten, by
which said alloying the quality of the steel is improved. I prefer to carry.
my Invention into effect in the manner hereinafter explained, but I do not
limit myself thereto as the method of carrying my Invention into effect. may.
be varied without departing from the nature of my said Invention.
I pulverize or crush the common ore of tungsten or tungstate of iron and
manganese, known as wolfram or wolfram ore, and having mixed it with
carbonaceous matter I introduce it into the melting pots or crucibles along
with the blister steel or other material ordinarily employed for melting into
cast steel, and I then heat the mixture in the pots or crucibles placed in
ordinary furnaces for melting steel until the contents of the pots are melted
and the metal is in a fluid state, when the crucibles are to be withdrawn from
the furnaces, and the melted alloy of tungsten and cast steel is then poured

page_text: into suitable ingot or other moulds to form ingots or castings of the required
size or form. The pure ores or oxydes of tungsten or tungstic acid may
be used in place of the common wolfram or tungstate of iron and manganese,
but I prefer to use the latter as more economical and as containing oxyde of
manganese, which facilitates the fusion of the mixture. The proportion of
carbonaceous matter to be mixed with the wolfram varies according to the
nature of the ore and its richness in metallic contents, but for wolfram or ore
of tungsten, which contains 50 per cent. of that metal, I find in practice that
it is sufficient to mix a given weight of such wolfram or tungsten ore with
from one-fourth to three-fourths of its weight of carbonaceous matter, although
a larger proportion of carbonaceous matter may be used when a denser or
harder alloy is required.
"
The proportion of the tungsten ore or wolfram and carbonaceous matter
mixed with the steel to be melted may be varied at pleasure, observing that
the greater the proportion of pulverized tungsten ore or wolfram and car-
bonaceous matter added to and melted with the cast steel, the greater will be
the proportion of metallic tungsten in the resulting alloy; but in practice I
find that when the following proportions are used, very excellent results are
obtained:
1st. I take blister steel converted for melting, 40 lbs.; clean wolfram ore
pulverized 1lbs., previously mixed with 1 lb. of melted pitch,-2 lbs. This
I introduce into a clay pot or crucible, and heat it, placed in an ordinary
furnace for melting steel, until it is melted, and I then pour the melted metal
into an ingot mould or other suitable mould.
2nd. I take good charcoal or other bar iron, 40 lbs.; charcoal, preferably
that of oak, in small pieces, 8 oz. ; clean wolfram ore, 2 lbs., mixed with 1 lb.
of melted pitch,-3 lbs. This I introduce into a melting pot or crucible, and
heat it, placed in an ordinary melting furnace for melting steel, until it is
melted, and I then pour the melted metal into an ingot mould, or other
suitable mould.
3rd. I take good charcoal bar iron, such as Swedish bars, 32 lbs.; charcoal,
preferably oak, in small pieces, 6 oz.; clean pulverized wolfram 4 lbs., previously
mixed with 2 lbs. of melted pitch, and the compound, when cool, broken small
for convenience in packing into the pots,-6 lbs. This I introduce into a
melting pot or crucible such as is used for melting steel, placed in an ordinary
furnace for melting cast steel. I then heat the mixture until it is melted, and
I then pour the fluid metal into an ingot mould or other suitable mould as
may be required.
The ingots or castings of the alloy of tungsten and cast steel which I thus
'

page_text: obtain, may be rolled or hammered into sheets or bars in the usual manner.
practised. in rolling or drawing cast steel to the sizes required. I do not,
however, confine myself to the proportions I have here set down as they may
be varied according as it is desired to alloy a greater or smaller proportion of
the tungsten with the cast steel.
The pulverized wolfram or tungsten ore may be mixed with charcoal or
other carbonaceous matter, but I have found that in practice common pitch
answers very well, and I first melt the pitch in a pot or pitch kettle and then
stir in the requisite proportion of pulverized tungsten ore or wolfram, after
which I pour out the mixture upon a smooth cold stone, and when cold it is
to be broken up into small pieces of a convenient size for packing into the
melting pots along with the steel. I also effect the alloy, of tungsten with
cast steel by adding to, and melting with cast steel metallic tungsten, by what-
ever process it may have been reduced from its ores, and I also effect the
alloy of tungsten with cast steel by adding to and melting with the cast steel a
metallic alloy of iron and tungsten, previously reduced from ores of tungsten
and iron; combined or from the native ores of tungsten and iron known as
tungstates of iron. But in practice 1 find that the alloy of tungsten with
cast steel is readily and economically effected in the manner I have above
described by melting with the cast steel a compound of tungsten ore or
wolfram or tungstic acid, pulverized and mixed with carbonaceous matter,
such as pitch, resin, coal tar, charcoal, &c.
The essence of my Invention consists in forming an alloy, of cast steel with
metallic tungsten, either by melting a mixture of tungsten ore or oxyde and
carbonaceous matter with cast steel or otherwise, by melting metallic tungsten
or a metallic alloy of tungsten and iron with cast steel..
SPECIFICATION, in pursuance of the conditions of the Letters Patent, filed
by the said Robert Mushet in the Great Seal Patent Office on the
11th July 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MUSHET, of Coleford, in the County of Gloucester, Metallurgist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of January, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto

page_text: me, the said Robert Mushet, Her special licence that. I, the said Robert
Mushet, my executors, administrators, and assigns, or such others as. I, the
said Robert Mushet, my executors, administrators, and assigns, should at any
tiune 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
OR IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL," upon the condition
(amongst others) that I, the said Robert Mushet, my executors or adminis-
trators, by an instrument in writing under niy, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the said Inven-
tion, 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
performed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
My Invention consists in alloying cast steel with the metal tungsten, by
which said alloying the quality of the steel is improved. I prefer to carry my
Invention into effect in the manner herein-after explained, but I do not limit
myself to the precise method described, as the method of carrying my.
Invention into effect may be. varied without departing from the nature of my
Invention.
.
T
I pulverize or crush the common ore 'of tungsten or tungstate of iron and
manganese, known as wolfram or wolfram ore, and having mixed the powdered
ore with carbonaceous matter I introduce the mixture into melting pots or
crucibles along with the blister steel or the materials which on being melted
form cast steel; and I then heat the mixture in melting pots or crucibles
placed in ordinary furnaces for melting steel, until the said materials in the
pots are melted and the metal is in a liquid state, when the crucibles, are to
be withdrawn from the furnaces, and the melted steel or alloy of tungsten and
cast steel is then poured into suitable ingot or other moulds to form ingots
or castings of the required size or form. The pure ores or oxides of tungsten
or tungstic acid may be used in place of the common wolfram or tungstate-of
iron and manganese, but I prefer to-use the latter as more economical, and as
containing oxide of manganese which facilitates the fusion of the mixture.
The proportion of carbonaceous matter to be mixed with the wolfram varies
according to the nature of the ore and its richness in metallic- contents, but

page_text: for wolfram or ore of tungsten which contains 50 per cent. of that metal, I
find in practice that it is sufficient to mix a given weight of such wolfram or
tungsten ore with from one-fourth to three-fourths of its weight of carbonaceous
matter; although a larger proportion of carbonaceous matter may be used
when a denser or harder steel is required.
The proportion of the tungsten ore or wolfram and carbonaceous matter
mixed with the steel to be melted may be varied according to the qualities
required in the steel to be manufactured, the greater the proportion of
pulverized tungsten ore or wolfram and carbonaceous matter added to and
melted with the cast steel, the greater will be the proportion of metallic
tungsten contained in the resulting steel, and the harder and denser will the
said steel be: When I employ wolfram or tungsten ore containing from forty-
eight to fifty-four per centum of its weight of metallic tungsten, I find that
the following proportions give excellent results :-
First, I take blister steel converted for melting, or, as it is termed, "highly
converted," 40 lbs.; clean wolfram ore, pulverized, 1½ lbs., previously mixed
with 1 lb. of melted pitch,-2 lbs. This mixture I introduce into a clay pot
or crucible, and heat it in an ordinary furnace for melting steel until the
said mixture is melted, and I then pour the melted steel or alloy of steel and
tungsten into an ingot mould or other suitable mould.
Second, I take good charcoal bar iron, such, for example, as Swedish bar
iron or other bar iron, 40 lbs.; charcoal, preferably that of oak, in small
pieces or nubs, about the size of a nut, and under 8 oz.; clean wolfram ore
2 lbs. mixed with 1 lb. of melted pitch,-3 lbs. This mixture I introduce into
a melting pot or, crucible, and heat it in an ordinary melting furnace for
melting steel until the said mixture is melted, and I then pour the melted
steel or alloy into an ingot mould or other suitable mould.
Third, I take good charcoal bar iron, such as Swedish bars, 32 lbs. ;
charcoal, preferably oak, in small nubs or pieces, 6. oz.; clean wolfram
pulverized 4 lbs., mixed previously with 2 lbs. of melted pitch, and the com-
pound, when cool, broken small for convenience in packing into the pots,-
6 lbs. This mixture I introduce into a melting pot or crucible such as is used
for melting steel, placed in an ordinary furnace for melting cast steel. I heat
the said mixture until it is melted, and I then pour the fluid metal into an ingot
mould or other suitable mould, as may be required. The ingots or castings
of cast steel or of the alloy of tungsten and cast steel which I thus obtain may
be rolled or hammered into sheets or bars of the required sizes in the manner
usually practised in rolling or drawing cast steel. When harder steel or alloy
of tungsten and steel is required than the mixtures already described produce,

page_text: I increase the relative quantity or proportion of pitch or resin mixed with the
pulverized wolfram, observing that the greater the relative quantity or pro-
portion of pitch or resin added to the pulverised wolfram, the harder will be
the steel or alloy of tungsten and cast steel obtained by melting the said
mixture of pitch or resin and pulverised wolfram with the steel, the relative
quantity or proportion of the said steel in the mixture remaining the same.
I do not, however, confine myself to the proportions I have here set down,
as they may be varied according as it is desired to alloy a greater or smaller
proportion of tungsten with the cast steel. The pulverised wolfram or
tungsten ore may be mixed with charcoal or other carbonaceous matter, but I
have found that in practice common pitch answers very well, and in order to
mix the pitch and wolfram I first melt the pitch in a pot or pitch kettle, and
then stir in the requisite proportion of pulverised tungsten ore or wolfram,
after which I pour out the mixture upon a smooth cold stone, and when cold
the said mixture is to be broken up into small pieces of a convenient size for
packing into the melting pots along with the steel, the said pieces being of the
size of a bean, or smaller.
I also effect the alloy of tungsten with cast steel, by adding to and melting
with cast steel metallic tungsten, by whatever process or method the tungsten
may have been reduced from its ores; and I also effect the alloy of tungsten with
cast steel by adding to and melting with the said cast steel a metallic alloy of
iron and tungsten previously reduced from ores of tungsten and iron combined,
or from the native ores of tungsten and iron, known as tungstates of iron.
But in practice I find that the alloy of tungsten with cast steel is readily and
economically effected in the manner I have herein first described, that is to
say, by melting with the cast steel a compound of tungsten ore or wolfram, or
tungstic acid pulverised and mixed with carbonaceous matter, such as pitch,
resin, coal tar, or charcoal.
Having thus described the general nature of my Invention, I will proceed
to describe such modifications of my said Invention, and such manipulating
details as I believe will be found to facilitate the practice of my said Invention.
prepare the ore of tungsten, commonly called wolfram, for my process by
grinding, crushing, or pulverising it, and passing it through a fine sieve or
riddle, and though it is not absolutely requisite to reduce the said wolfram to
so fine a powder, I nevertheless prefer to crush or pulverise the said wolfram
to so fine a powder that it will pass the meshes of a sieve or riddle of fifty
imeshes per linear inch, or two thousand five hundred meshes per square inch,
because when thus finely pulverised it is more readily mixed with the carbo-
naceous matter which I prefer to use, namely pitch or resin, and the tungsten

page_text: is more readily reduced and alloyed with the steel than when the said wolfram:
is less finely pulverised. I avoid the use of wolfram containing arsenic or
much mixed with quartz, spar, veinstuff, or gangue. When the wolfram is
very pure, and contains from seventy to seventy-five per centum of tungstic
acid, or about sixty per centum of its weight of metallic tungsten, I pulverise
and prepare the said wolfram as I have herein-before described. I then mix
a given weight of it with an equal weight of pitch or resin previously melted
in a pitch pot or kettle, introducing the said prepared pulverised wolfram into
the melted pitch, and stirring the mixture until the said wolfram is thoroughly
mixed with the said melted pitch or resin. I then pour the mixture upon a
stone slab or pavement, which may be previously moistened to prevent the
mixture from adhering to the said slab or pavement. When cold the said
mixture may be broken into pieces about the size of a nut and smaller ready
When wolfram of the kind last described is used, that is to say,.
wolfram containing about sixty per centum of metallic tungsten, I find that
the following proportions produce excellent results:-
for use.
First, blister steel converted for melting, 46 lbs.; mixture of pulverised
wolfram, containing about sixty per cent. of metallic tungsten and pitch or
resin in equal proportions of the said mixture, 1 lb. These substances I intro-
duce into a melting pot or crucible placed in a steel melting furnace, and I.
heat the said substances therein until the blister steel is melted, and the
wolfram is reduced by means of the pitch or resin, and its tungsten alloyed
with the steel. I then withdraw the melting pot from the furnace, and pour
the steel, or alloy of steel and tungsten, into an ingot or other mould in the
manner practised by steel melters.
i
"
. Second, good charcoal bar iron, such, for example, as Swedish bar iron,
44 lbs.; charcoal in small pieces or nubs, about the size of large peas or small
beans, about 8 oz.; mixture of pulverized wolfram, containing about sixty
per cent. of metallic tungsten, and pitch or resin in equal proportions of the
said mixture, 1 lb. These substances I introduce into a melting pot .or
crucible placed in a steel melting furnace, and I heat the said substances
therein until the iron and charcoal are melted into cast steel, and the wolfram
is reduced, and its tungsten is alloyed with the said steel. I then withdraw
the melting pot from the furnace, and pour the steel or alloy of steel and
tungsten into an ingot mould or other mould in the manner practised by
steel melters.
Third, when I wish to obtain cast steel containing a larger alloy of tungsten
tban is produced from any of the mixtures herein-before last described, .I-
employ the following proportions:-Charcoal bar iron, such, for instance,

page_text: .
as: Swedish bar iron, cut into small pieces, 40 lbs.; charcoal, in small pieces
or,nubs about the size of peas or small, beans, 8 oz.; mixture of pulverised
wolfram, containing about, sixty per cent. of metallic tungsten, and pitch or
resin in equal proportions of the said mixture, 4 lbs. These substances I
introduce into a melting pot or crucible placed in an ordinary steel melting
furnace, and I heat, them therein until the bar iron and charcoal are melted
into cast steel, and the tungsten of the wolfram is reduced by the pitch or
resin, and is. alloyed with the steel. I then withdraw, the melting pot from
the furnace, and pour the melted steel or alloy of tungsten and steel
into an ingot or other mould in the manner usually practised by steel
melters.
When tungstic acid is employed instead of wolfram for my process, I prefer
to mix the said tungstic acid, previously finely pulverized, with pitch or resin,
in the following proportions, namely, from, ten to twenty pounds of finely
pulverized tungstic acid. to twenty pounds of pitch or resin; and of the com-
pound thus formed I add. from eight ounces to two pounds to forty pounds of
good charcoal bar iron, mixed with from six to eight ounces of charcoal, and
in either case I introduce these substances into a melting pot or crucible
placed in an ordinary steel, melting furnace, and I beat them therein until
the steel is melted. I then withdraw the melting, pot from the furnace, and
pour the steel' or alloy of tungsten and steel into an ingot mould, or into any
other kind of mould' which it may be required to employ.
When puddled steel is to be alloyed with tungsten, I have found that the
following proportions afford an excellent result, namely, puddled steel cut
into small pieces, 48 lbs.; charcoal in small pieces or nubs, about the size of
peas or small beans, 2½ ozs. ; purest wolfram, containing about sixty per cent.
of metallic tungten or pure tungstic acid, finely pulverized, mixed with an
equal weight of pitch or resin, of the compound thus formed, 1 lb. These
materials I introduce into a melting pot.placed in an ordinary steel melting
furnace, and heat them therein until the steel is melted, and the wolfram
reduced, and its tungsten alloyed with the said steel: The melting pot is
then withdrawn from the furnace, and the steel or alloy of steel and tungsten
is poured into an ingot or other mould.
Having thus described the nature of my Invention, and the methods by
which I prefer to carry it into effect, I wish it to be understood that I do not
confine myself to the relative proportions of materials herein-before described,
as the proportions must be varied according to the particular nature of the
materials employed; but I wish it to be understood that when I wish to
increase the hardness of the steel or alloy of steel and tungsten, I increase_

page_text: the relative proportion of the carbonaceous matter added to and mixed with
the pulverized wolfram or tungstic acid, and by thus increasing or diminishing
the relative proportion of carbonaceous matter added to and mixed with the
pulverized wolfram or tungstic acid, the harder or softer will be the steel or
alloy of steel and tungsten obtained by melting steel or materials which in
melting form steel with the said compound of wolfram or tungstic acid and
carbonaceous matter, and by varying the relative proportions of the said
compound added to a given weight of steel, the resulting cast steel or alloy of
cast steel and tungsten may be made of any required degree of hardness or
softness.
The essence of my Invention consists in improving cast steel by alloying
the said cast steel with metallic tungsten, and I prefer to effect this improve-
ment or alloying by melting steel or materials which when melted together
produce steel, as, for instance, bar iron and charcoal, with a compound formed
of pulverized wolfram mixed with pitch or resin; but other carbonaceous
matters may be used instead of the said pitch or resin, and tungstic acid mixed
with carbonaceous matter may be employed instead of wolfram. Or metallic
tungsten or a mixture of metallic tungsten and iron may be employed, and be
melted with the steel, so as to improve the said steel by alloying metallic
tungsten therewith. Manganese or other fluxes may be introduced along with
the steel and wolfram into the melting pot or crucible, but I do not claim as
of my Invention the use of manganese or other fluxes, neither is their use
essential to the success of my Invention.
In witness whereof, I, the said Robert Mushet, have hereunto set my
hand and seal, this Twenty-fifth day of June, in the year of our Lord
One thousand eight hundred and fifty-nine.
Witnesses,
EDW. M. MUSHET,
Coleford, Gloucestershire.
BROOKLYN MUSHET,
Coleford, Gloucestershire.
ROBT. MUSHET. (L.S.)