IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1877

page_text: LETTERS PATENT to Robert Hadfield, of Southampton Buildings, Chancery
Lane, London, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF STEEL."
Sealed the 19th June 1877, and dated the 7th March 1877.
PROVISIONAL SPECIFICATION left by the said Robert Hadfield at the Office
of the Commissioners of Patents on the 7th March 1877.
ROBERT HADFIELD, of Southampton Buildings, Chancery Lane, London. "IM-
PROVEMENTS IN THE MANUFACTURE OF STEEL."
This Invention has for its object certain improvements in the manufacture of
steel, whereby not only is a very superior quality of metal produced, but at the
same time a considerable economy both in time and in the requisite materials is
effected. I proceed as follows:-Where a blast furnace or blast furnaces are
employed in connection with the manufacture of steel, I charge such furnace or
furnaces with suitable hematito ore, or any other suitable ore which is free from
phosphorus and sulphur, and smelt the same therein until it is reduced to a molten
state. I then run such molten metal direct from such blast furnace or furnaces into
any suitable converter, preferably a Bessemer converter, instead of running the
metal into "pig" as is now ordinarily practised, thus avoiding any necessity to
remelt the pigs, thereby considerably economising both labour and fuel. I then
blow and treat such molten metal, whilst in the converter, in the ordinary manner,
whereby it is greatly purified; I then run such metal from the converter into any
suitable furnace or furnaces, which furnace or furnaces I previously heat to a
sufficient degree so as to avoid any injurious cooling of the molten metal whilst
under treatment, and I then retain the metal in such last-mentioned furnace or
furnaces for any suitable period of time, such period varying according to the quality
or temper of the steel required to be produced, that is to say, whether it be what is
technically known as "hard," "soft," or "medium" steel. In this way I possess
entire control over the metal under treatment, and am thus enabled to thoroughly
eliminate any superfluous carbon or other impurities which might tend to prejudice.
DC

page_text: its quality, and thus a very superior class of steel is obtained as the result of my
improved process.
In those cases where a blast furnace is dispensed with, I melt the pig iron in any
suitable cupola or air furnace or furnaces, and when ready I run the same into a
suitable converter and treat it as already described in the first-mentioned process.
The advantages of any improved process are the facility with which the metal
under treatment is held in entire control, thus enabling me to produce a higher
quality of steel than is obtained by any of the present known methods, an immense
economy in time, varying from 6 to 10 hours, according to the quality and tomper of
steel required to bo produced, and a consequent saving of the labour and fuel
requisite for its manufacture.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Hadfield in the Great Seal Patent Office on the 7th September
1877.
ROBERT HADFIELD, of Southampton Buildings, Chancery Lane, London. “IM-
PROVEMENTS IN THE MANUFACTURE OF STEEL."
This Invention has for its object certain improvements in the manufacture of
steel, whereby not only is a very superior quality of metal produced, but at the
same time a considerable economy both in time and in the requisite materials and
fuel for the manufacture thereof is effected. I proceed as follows:-Where a blast
furnace or blast furnaces are employed in connection with the manufacture of steel,
I charge such furnace or furnaces with suitable hematite ore, or any other suitable
ore which is free from phosphorous and sulphur, and smelt the same therein until it
is reduced to a molten state. I then run such molten metal direct from such blast
furnace or furnaces into any suitable converter or converters, preferably a Bessemer
converter, instead of running the metal into "pig" as is now ordinarily practised,
thus avoiding any necessity to remelt the pigs, thereby considerably economising
both labour and fuel. I then blow and treat such molten metal whilst in the con-
verter in the ordinary manner, whereby it is greatly purified; I then run such
metal from the converter into any suitable furnace or furnaces, preferably a
Siemens-Martin furnace, which furnace or furnaces I previously heat to a sufficient
degree so as to avoid any injurious cooling of the molten metal whilst under treat-
ment, and I then retain the metal in such last-mentioned furnace or furnaces for
any suitable period of time, such period varying according to the quality or temper
of the steel required to be produced, that is to say, whether it be what is technically
known as "hard," "soft," or "medium" steel. In this way I possess entire control
over the metal under treatment, and am thus enabled to thoroughly climinate any
superfluous carbon or other impurities which might tend to prejudice its quality,
and thus a very superior class of steel is obtained as the result of my improved
process.
In those cases where a blast furnace is dispensed with, I melt the pig iron in any
suitable cupola or air furnace or furnaces, and when ready I run the same into a
suitable converter or converters, such as a Bessemer converter or converters, and
treat it as already described in the first-mentioned process.
The advantages of my improved combined process are the facility with which the
metal under treatment is held in entire control, thus not only enabling me to pro-
duce a far higher quality of steel than is obtained by any of the present known
methods, but also effecting thereby an immense economy in time, varying from 6 to
10 hours, and thus ensuring a consequent saving of the labour and fuel requisite for
its manufacture, at the same time that by such improved combined process I am 5
enabled to carbonize the steel according to the quality and temper required to be
produced.

page_text: Having now particularly described and ascertained the nature of my said
Invention and the manner of carrying the same into effect, I would have it under-
stood that I claim the manufacture of steel by the improved combined process
herein-before described, and particularly I claim the running of the molten metal
from a Bessemer or any other suitable converter or converters into a suitable
furnace or furnaces, preferably a Siemens-Martin furnace or furnaces, substantially
as herein-before described.
In witness whereof, I, the said Robert Hadfield, have hereunto set my hand
and seal, this Seventh day of September, in the year of our Lord One thousand
eight hundred and seventy-seven.
ROBERT HADFIELD. (L.S.)