IMPROVEMENTS IN THE TREATMENT OF STEEL WITH FERRO MANGANESE
Year: 1884

page_text: COMPLETE SPECIFICATION.
I, ROBERT HADFIELD of Sheffield in the County of York Steel Manufacturer
do hereby declare the nature of my Invention for IMPROVEMENTS IN THE
TREATMENT OF STEEL WITH FERRO MANGANESE and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :—
This Invention relates to further improvements in my newly discovered
treatment of steel with high per centages of manganese as described and claimed
by me in the Specification of Letters Patent No 200 of the year 1883.
In such Specification I have specified the treatment of steel with per centages of
manganese varying from 7 to 20°
Now my present improvements relate to a further development of such novel
principle of treatment and consist in 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 20% to 30%. such per centage being regulated according to the purposes for
which the steel is required.
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.
To carry out this modified treatment I take ferro manganese of the quality
before specified in suitable proportions according to the per centage of manganese
required in the steel undor treatment-I then carefully melt the same in a
reverberatory or other suitable furnace after which I run or pour the same into the
molten steel or into molten iron or metal either wholly or to a great extent
decarbonised and refined or treated as before mentioned. I then thoroughly blend
the same into one homogeneous mass by stirring or rabbling after which I run the
steel so produced into ingot or other moulds made either of iron, sand or other
suitable material and allow it to cool.
The distinctive advantages of employing such increased per centages of
manganese exceeding 20 and up to 30° as against per centages varying from 7
to 20% are 1 That it is free from the fibrous condition which I have observed
in steel manufactured with such lower per centages-2nd That considerably

page_text: increased hardness combined with extreme toughness are obtained, in the steel so
manufactured-In addition to these advantages it possesses great fluidity and
soundness from honeycomb and other defects thus enabling castings to be made
with great uniformity and regularity and it requires neither tempering rolling
forging or hammering-The use of silicon to obtain soundness is also unnecessary,
Such steel is particularly adapted for casting safes complete or for casting the
linings of safes, railway wheels, armour face plates, rolls to replace those of chilled
cast iron and many other purposes where excessive hardness combined with extreme
toughness is requisite.
•
Having now particularly described and ascertained the nature of my said
Invention and what manner the same is to be performed I declare that what
I claim is the improved method of treating iron or metal either wholly or to a great
extent decarbonised, or steel produced by any of the ordinary processes by
introducing therein and thoroughly blending therewith in the manner herein before
specified a per centage of manganese varying from over 20 up to and including
30° according to the purpose for which the steel is intended to be used.
WOOD WHEN Way or may 100T.
SHIRLEY BOWDEN,
Agent for the
said Robert Hadfield.