IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL
Year: 1853

page_text: LETTERS PATENT to Joseph Leon Talabot, of Chaussée d'Antin,
No. 57, Paris, Iron Master, and John Davie Morries Stirling, of
the Larches, near Birmingham, in the County of Warwick,
Esquire, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF CAST STEEL."
Sealed the 27th October 1853, and dated the 15th August 1859.
PROVISIONAL SPECIFICATION left by the said Joseph Leon Talabot
and John Davic Morries Stirling at the Office of the Commis-
sioners of Patents, with their Petition, on the 15th August 1853.
We, JOSEPH LEON TALABOT, of Chaussée d'Antin, No. 57, Paris, Iron.
Master, and JOHN DAVIE MORRIES STIRLING, of the Larches, near
Birmingham, in the County of Warwick, Esquire, do hereby declare
the nature of the Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
CAST STEEL" to be as follows:-
This Invention has for its object means of improving and varying
the quality and character of cast steel, and consists of melting steel with
oxide of iron, of tin, of zinc, of chrome, of baryta, of strontia, and of
lime; and according to which of these matters are used, and the
quantities or proportions thereof, so will be the quality or character of
cast. steel produced.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Joseph Leon Talabot and John Davie Morries
Stirling in the Great Seal Patent Office on the 15th February 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,
JOSEPH LEON TALABOT, of Chaussée d'Antin, No. 57, Paris, Iron
Master, and JOHN DAVIE MORRIES STIRLING, of the Larches, near
Birmingham, in the County of Warwick, Esquire, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifteenth day of August, in the year
of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said Joseph Leon Talabot and John Davie
Morries Stirling, Her special licence that we, the said Joseph Leon
Talabot and John Davie Morries Stirling, our executors, administrators,
and assigns,. or such others as we, the said Joseph Leon Talabot and
John Davie. Morrics Stirling, our 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 THE MANUFACTURE or CAST STEEL,"
upon the condition (amongst others) that we, the said Joseph Leon
Talabot and John Davie Morrics Stirling, by an instrument in writing
under our hands and seals, or under the hand and seal of one of us,
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 John Davies Morrics Stirling, on
behalf of myself and the said Joseph Leon Talabot, ilo 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:
Our Invention consists in modifying the character of steel by com-
bining with blister steel, when melting it, oxides of metals or of the
earthy bases, and thus producing cast steel of the character desired.

page_text: In manufacturing blister steel various qualities are made, of which
mild and highly converted steel are the two opposites; mild or low
carburetted steel, being produced by a shorter contact with charcoal in
the converting furnace; highly converted steel, or 'that more highly
charged with carbon, being produced by a longer exposure. By simply.
melting such classes of steel it is difficult repeatedly to get like quali
ties of cast steel, and it is the object of our Invention to modify the
quality of blister steel when melting it to produce cast steel, and this
we do by adding thereto an oxide of a metal or of an earthy base, or
oxides of metals or earthy bases, and on the quantity of such oxide
added when acting on like qualities of blister steel will depend the
quality of cast steel produced. Mild steel is much less fusible tlian
highly converted steel, and it is sometimes advantageous to lower
or bring back highly converted steel to the condition of mild steel by
melting it; and this we do by the addition of various oxides of which
those of iron and of calcium are suitable.
.
By varying the quantity of such oxides we produce certain and dis-
tinct qualities of cast steel from the same blister steel. If blister steel
of highly carburetted quality be melted with a small quantity of.an
oxide of iron (magnetic ore is preferred for this purpose, though other
oxide may be used) the cast steel will be very different from what
would result from simply melting the highly carburetted blister steel
alone; and it will be found that in proportion to the quantity of oxide of:
iron 50 will be the character of cast steel thus manufactured; hence by.
such means a manufacturer may with facility and certainty command
the quality of cast steel which he desires to produce.
The quantity of oxide of iron employed by us is from one to three
or four per cent., but we do not confine ourselves thereto. Oxide of
calcium and lime has a similar effect to the oxides of iron in reducing
the hardness of cast steel, and we employ it in the proportion of from
1/200 to 1/50th part of the weight of the steel. In using oxide of
tin in combination with blister steel, we find it better to apply the
same in combination with mild blister steel, or steel moderately car-
buretted, because it has the effect of hardening the cast steel produced;
and the addition of a two thousandth to one thousandth (2,1000th to
1/1000th part) of oxide of tin produces a very marked effect, similar to

page_text: that which would result from carrying on the ordinary converting pro-
cess for a longer period; hence the manufacturer will, by proportioning
the quantity of oxide of tin employed, be able to harden mild steel
to the degree desired, without carrying on the carburetting process to
so high degree, and at the same time cast steel of different degrees of
hardness may be obtained from the same quality of blister steel by melt-
ing different quantities of the blister steel with different proportions of
the oxide of tin.
Oxide of zinc has a toughening effect, and we use it, we believe, to
the greatest advantage when employing it at the rate of from one 1
four hundredth to one two hundredth part (1/400th to 1/200th) of the
weight of the steel employed.
We also use oxides or carbonates of the oxides of barium and other
earthy bases, and we add these according to the quality of the steel in
very small proportions or in the proportions, of from a four hundredth to
a hundredth part (4/100th to 1/100th part).
In thus employing oxides of metals or oxides of the earthy bases, or
combination of these, we believe the best means of doing so is to
introduce the quantity of the oxide to be used into the crucible or other
apparatus, cither at the same time with the blister steel, or when
the metal is in a pasty state. We would remark that we are aware
that oxide of manganese has before been used, and is now commonly
used in manufacture of cast steel, and we continue to use such matter
as heretofore in conjunction with the other oxides.
We would, in conclusion, state that altho' we have been particular s
in giving the precise quantities of the oxides used by us, we do not in.
any of the cases confine ourselves thereto.
In witness whereof, I, the said John Davic Morries Stirling, have
hereunto set my hand and seal, this Fifteenth day of February, in
the year of our Lord One thousand eight hundred and fifty-four.
Witness,
ARTHUR CARPMAEL.
J. D. MORRIES STIRLING. (L.S.)