IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by the said Robert Hadfield at the Office
of the Commissioners of Patents on the 12th January 1883.
ROBERT HADFIELD of Sheffield in the County of York Steel Manufacturer
"IMPROVEMENTS IN THE MANUFACTURE OF STEEL "
This Invention has for its object improvements in the manufacture of steel by
means whereof new and highly valuable properties long sought after but hitherto
unattainable are imparted thereto.
My invention consists in an improved use of the well known agent Manganese
which I employ in larger proportions than has been heretofore used
I am aware that Manganese has already been frequently employed in the manu-
facture of steel in proportions varying from 1 to 1%, per cent or thereabouts after
which it has from past experience been and still is generally believed that any
further addition thereof to the metal under treatment is deleterious and injurious
and only results in a worthless product, utterly valueless commercially, and conse-
quently any further addition thereof in excess of the proportions above mentioned
has been considered impracticable.
Now I have discovered that by adding the ordinary ferro-manganese of
commerce to iron or metal either wholly or partially decarbonized, and refined or
treated by any of the ordinary processes, or to steel produced by any of such
processes, in increased proportions sufficient to obtain or produce in the steel or
decarbonized iron or metal under treatment a per centage of Manganese varying
from 7 to 20 per cent (Such per centage being regulated according to the
purposes for which the steel is required) is attended with the most beneficial
results.
In carrying out my invention I use by preference a ferro-manganese containing
as high a per centage of manganese as possible but low in carbon silicon and other
foreign bodies.

page_text: This improved employment by me of manganese in increased proportions to
those hitherto used is entirely novel and renders the steel so manufactured harder,
stronger, denser, and tougher than steel as now forged and rolled
The advantages possessed by steel manufactured according to my improved
process may be briefly summarised as follows viz
1 Soundness that is freedom from honeycombs and other defects
2 Great toughness combined with extreme hardness whereby the hitherto
indispensable processes of rolling, forging, hammering, hardening and tempering
are entirely dispensed with thus effecting an enormous economy in time labor and
expense
3 Thinness and great fluidity thus enabling fine steel enstings to be made
without misrunning and nearly if not quite as smooth as inotal castings
4 A steel that does not settle inuch and yet is sound as although extremely hard
it does not draw like ordinary steel castings particularly at the junction of the
thick and thin parts.
5 By my improved process steel and steel castings can be made with unvarying
uniformity, regularity and success from mat-rials which are easily obtainable
6 Steel thus manufactured is specially adapted for making steel rolls to replace
those made of chilled metal as also for other castings, such as guns and armour
plates and for artillery purposes generally and also for railway and tramway wheels
and plant and for other similar purposes
7 The larger edged tools and articles known in the trade as steel toys as also
implements and parts of machinery, and other articles too numerous to mention
may be cast therefrom without requiring either forging or tempering and in the
case of large edged tools ready for use after grinding
By my improved employaient of manganese in the manufacture of steel I obtain
an entirely new quality of steel hitherto entirely unknown and far excelling any
steel heretofore manufactured
"
I may also add that my improved principle of manufacturo renders the use of
Silicon unnecessary in order to obtain soundness

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Hadfield in the Great Seal Patent Office on the
12th July 1883.
ROBERT HADFIELD of Sheffield in the County of York Steel Manufacturer
IMPROVEMENTS IN THE MANUFACTURE OF STEEL
This Invention has for its object improvements in the manufacture of steel by
means whereof new and highly valuable properties long sought after but hitherto
unattainable are imparted thereto
My invention consists in an improved use of the well known agent Manganese
which I employ in larger proportions than has been heretofore used or considered
practicable
:
I am aware that Manganese has already been frequently employed in the
manufacture of steel in proportions varying from 1 to occasionally as much
as 1%, per cent or thereabouts after which it has from past experience been and
still is generally believed that any further addition thereof to the metal under
treatment is deleterious and injurious and only results in a worthless product
utterly valueless commercially and con-equently any further addition thereof in
excess of the proportions above mentioned has been considered impracticable
Now it occurred to me that the belief thus generally entertained might probably
be erroneous and I therefore engaged in a long series of experiments and tests
with the object of discovering the truth of my surmise-After a considerable
expenditure both of time and capital I have at length discovered that by adding
the ordinary ferro-manganese of commerce to iron or metal either wholly or to a
great extent decarbonised and refined or treated by any of the ordinary processes,
or to steel produced by any of such processes in increased proportions sufficient to
obtain or produce in the steel or decarbonized iron or metal under treatment a
per centage of Manganese varying from 7 to 20 per cent the most beneficial results
are obtained-Such per centage is regulated according to the purposes for which
the steel is required-For instance to produce a steel suitable for armour plates
and other similar purposes I add about 10% of rich ferro-manganese containing
say 80% of manganese thus obtaining a steel containing about 10% of manganese.
To produce a steel suitable for railway plant and wheels I add about 11%, of
similar rich ferro-manganese thus obtaining a steel containing about 11% of man-
ganese To produce a steel suitable for steel toys and tools I add about 12°/
similar rich ferro-manganese thus obtaining a steel containing about 12%
manganese.
of
In carrying out my invention I in all cases use by preference a ferro-manganese
containing as high a per centage of manganese as possible but as low as possible
in carbon silicon and other foreign bodies and I proceed as follows I take ferro-
manganese containing sny 80 per cent of manganese or upwards in suitable pro-
portions according to the quality of steel required to be produced and having first
carefully melted the same in a reverberatory or other suitable furnace I then
pour the same into the molten steel under treatment and thoroughly incorporato
the same there with by well stirring them together until both are perfectly blended
in one homogeneous mass I then run the same into ingot or other suitable moulds
and allow it to cool after which it is ready for use as it requires neither tempering,
rolling, forging, or hardening.
This improved treatment of steel in the process of manufacture by employing
ferro-manganese in the increased proportions herein before mentioned or in other
suitable proportions according to requirements is entirely novel and renders the

page_text: steel so manufactured harder stronger denser and tougher than any steel now
manufactured even when forged and rolled
The advantages possessed. by steel manufactured according to my improved
treatment or process as invented and discovered by mo are numerous and of the
utmost commercial importance-They may be briefly summarised as follows vist
1 Freedom from honeycomb and other defects
2-Great toughness combined with extreme hardness whereby the hitherto
indispensable processes of rolling, forging, hammering, hardening and tempering
are entirely dispensed with thus effecting an enormous economy in time labor and
expense
3-Thinness and great fluidity thus enabling fine steel castings to be made
without misrunning and nearly if not quite as smooth as metal castings
4-A steel that does not settle much and yet is sound as although extremely
hard it does not draw like ordinary steel castings particularly at the junction of
the thick and thin parts.
5-By my improved process steel and steel castings can be made with unvarying
uniformity, regularity and success from materials which are easily obtainable
G-Steel thus manufactured is specially adapted for making steel rolls to replace
those made of chilled metal as also for other castings such as Guns and armour
plates and for artillery purposes generally and also for railway and tramway
wheels and plant and for other similar purposes
7-The larger edged tools and articles known in the trade as steel toys as also
implements and parts of machinery and other articles too numerous to mention
may be cast therefrom without requiring either forging or tempering and in the
case of large edged tools they are ready for use after grinding-By my improved
employment of manganese in the manufacture of steel I obtain an entirely new
quality of steel hitherto totally unknown aud far excelling any steel heretofore
manufactured.
I may also add that my improved treatment renders the use of Silicon
unnecessary in order to obtain soundness
Having thus fully described the nature and operation of my said invention I
claim as novel and of my invention and discovery the improved method of treating
iron or metal either wholly or to a great extent decarbonized or steel while in
course of manufacture by introducing therein a sufficient proportion of rich ferro-
manganese to produce in such decarbonized iron or metal or steel a per centage of
manganeso varying between but not less than 7 nor more than 20 per cent
according to the purpose for which the steel is to be used whereby I dispense with
the proce-ses of tempering rolling, forging, and hardening and obtain a steel of
far higher quality and of much greater commercial value than any hitherto
manufactured or produced at considerably less cost in time labour and expense
In witness whereof I the said Robert Hadfield have hereunto set my hand
and seal this twelfth day of July in the year of Our Lord One thousand
eight hundred and eighty three.