IMPROVEMENTS IN CONVERTING OR PARTIALLY CONVERTING IRON INTO STEEL
Year: 1872

page_text: LETTERS PATENT to Edward John Payne, of Packwood, in the
County of Warwick, Architect, and William Clarke, of Dudley,
in the County of Worcester, Gentleman, for the Invention of
" IMPROVEMENTS IN CONVERTING OR PARTIALLY CONVERTING IRON INTO
STEEL"
Sealed the 4th March 1873, and dated the 5th October 1872.
PROVISIONAL SPECIFICATION left by the said Edward John Payne
and William Clarke at the Office of the Commissioners of Patents,
with their Petition, on the 5th October 1872.
We, EDWARD JOHN PAYNE, of Packwood, in the County of Warwick,
Architect, and WILLIAM CLARKE, of Dudley, in the County of Worcester,
Gentleman, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN CONVERTING OR PARTIALLY CONVERTING IRON INTO STEEL," to be
as follows, that is to say :-
:―
This Invention relates to the manufacture of steel by the process of
cementation, and also to the casehardening or partial conversion of iron
by a similar process.

page_text: We take wrought iron in any form and enclose it in a cement made
of coal tar, pitch, or its constituents, the resultants of the destructive
distillation of coal in the manufacture of carburetted hydrogen or
ordinary coal gas; this pitch is exceedingly rich in carbon, and when
subjected to but a moderate heat is readily vapourised. The pitch, by
preference reduced to powder and completely enveloping the iron to be
converted, is enclosed in a box of sheet iron or other vessel, which will
admit of being thoroughly luted or sealed, and is removed to a furnace
of any suitable description, the usual cementing furnace is not necessary,
and subjected to the fire until the carbon of the pitch has become
vapourised and has combined with the iron and converted it into steel;
the pitch being so easily fusible and yielding its carbon so freely the
time required for the process of conversion is considerably reduced, for
some qualities of steel requiring only as many hours as the ordinary
process of cementation with charcoal requires days to produce. In
addition to this advantage steel of a more uniform quality is the result,
and it is produced with more certainty as to quality, as the cement being
wholly absorbed by the iron and leaving no residuum the exact charge
to produce any given quality of steel can be ascertained and regulated
by weight.
In the same manner iron articles may be converted on their surfaces
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward John Payne and William Clarke in the
Great Seal Patent Office on the 5th April 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wo, EDWARD
JOHN PAYNE, of Packwood, in the County of Warwick, Architect, and
WILLIAM CLARKE, of Dudley, in the County of Worcester, Gentleman,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of October, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Edward John Payne and
William Clarke, Her special liceuse that we, the said Edward John

page_text: Payne and William Clarke, our executors, administrators, and assigns,
or such others as we, the said Edward John Payne and William
Clarke, 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 CONVERTING OR PARTIALLY CONVERTING IRON
INTO STEEL," upon the condition (amongst others), that we, the said
Edward John Payne and William Clarke, our executors or adminis-
trators, by an instrument in writing under our, 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 we, the said Edward John Payne and William
Clarke, do hereby declare the nature of our 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 :-
This Invention relates to the manufacture of steel by the process of
cementation, and also to the casebardening or partial conversion of iron
by a similar process.
We take the wrought iron in any form and enclose it in a cement made
of coal tar, pitch, or its constituents, the resultants of the destructive
distillation of coal in the manufacture of carburetted hydrogen or
ordinary coal gas; this pitch is exceedingly rich in carbon, and when
subjected to but a moderate heat is readily vapourised. The pitch, by
preference reduced to powder and completely enveloping the iron to be
converted, is enclosed in a box of sheet iron or other vessel, which will
admit of being thoroughly luted or scaled, and is removed to a furnace
of any suitable description, the usual cementing furnace is not necessary,
and subjected to the fire until the carbon of the pitch has become
vaporised and has combined with the iron and converted it into steel;
the pitch being so easily fusible and yielding its carbon so freely the
time required for the process of conversion is considerably reduced, for
some qualities of steel requiring only as many hours as the ordinary

page_text: process of cementation with charcoal requires days to produce. In
addition to this advantage steel of a more uniform quality is the result,
and it is produced with more certainty as to quality, as the cement being
almost wholly absorbed by the iron and leaving little or no residuum the
exact charge to produce any given quality of steel can be ascertained 5
and regulated by weight.
In some cases we prefer to mix with the pitch vegetable tar, and this
may be added in proportions to suit the quality of the metal under
operation.
In the same manner iron articles may be converted on their surfaces 1
only, or casehardened, either by using powdered pitch alone or in
combination with the ordinary materials used for hardening, such as
powdered charcoal or coal, or bone dust, and especially the waste or
spent bone hardening.
Having thus described the nature of our said Invention, and the 1
manner in which the same is to be carried into effect, we claim without
limiting ourselves to these precise details the improvements in converting
or partially converting iron into steel, substantially in manner as herein
more fully set forth and specified.
In witness whereof, we, the said Edward John Payne and William 2
Clarke, have hereunto set our hands and seals, this Second day
of April, in the year of our Lord One thousand eight hundred
and seventy-three.