IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1862

page_text: LETTERS PATENT to Johann Carl Schemmann, of Hamburg, Mer-
chant, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE OF
STEEL."
Sealed the 13th February 1863, and dated the 21st August 1862.
PROVISIONAL SPECIFICATION left by the said Johann Carl Schemmann
at the Office of the Commissioners of Patents, with his Petition, on
the 21st August 1862.
I, JOHANN CARL SCHEMMANN, of Hamburg, Merchant, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE OF
STEEL," to be as follows:-
My Invention consists in operating upon iron in the puddling furnace, and
subsequently in manner hereafter described. When iron in the puddling
furnace reaches that point where the escape of carbonic oxide ceases, the
melted iron assumes a granular state. In this state the melted iron has lost
its properties as pig or raw iron, the greater portion of the carbon having
escaped, and part of the other heterogeneous substances commonly found in
iron having been volatilized or mixed with the slag, the iron in this state is
no longer pig iron, but has become purified iron containing a certain quantity
of carbon, and in this combination it is hard steel richly saturated with
carbon. On the metal being worked-through still further, under-suitable
regulation of the furnace, every conversion beyond this granular state causes

page_text: a decrease of carbon in the metal, until it will finally become iron. Between
each grade of further decarbonization the mass has become steel containing a
different amount of carbon, and is of a different degree of hardness, say, from
the maximum to the minimum. Up to the present this fact has not been
sufficiently acknowledged, or rather, no attention has been paid to discover a
process in order to obtain steel at the various stages of the decarbonization.
Now, I commence to operate upon the iron as soon as it assumes the granular
state in the puddling furnace. On the mass reaching that granular state
which I consider fit for the particular kind of steel I desire to produce, I at
once shut off the draught in the furnace, open the door, and take the whole
mass out as quickly as possible, and throw it into cold water, by which means
the steel hardens, and gets rid of the slag and cinder.
It will need attention and experience to determine the right moment for
obtaining that particular kind of steel required, yet a pretty infallible guide
will be found in the appearance of the mass, and even if the right moment
should escape steel will be produced suitable for some purpose at any rate.
The more the mass consists of isolated granules the greater is the amount of
carbon it contains; and, again, the more these granules combine and weld
together, the greater is the decarbonization of the same, consequently the
amount of carbon or the hardness of the steel to be produced will depend on
the choice of the moment, or rather on the state in which the mass has been
taken out of the furnace and hardened. If, for instance, I take the mass out
at that moment when the granules have just formed, I obtain highly-car-
bonized and extremely hard steel with isolated grains. If the working or
puddling of the mass be carried on still further carbon escapes, and the grains
begin to weld to each other, and the higher the decarbonization the more the
granules will unite and weld to each other. If I take the mass out of the
furnace in the first state of welding of the granules, I obtain steel in granular
porous sponge-like lumps. In each following stage these lumps come out in
a more combined and less porous state, and the more or less porous they are
the more or less hard is the steel produced. The steel thus made is fit for
further working simply by hammering it into pieces, but I prefer to still
better prepare it for further application and working by carefully crushing and
reducing it under a stamp hammer, or rollers, or in a mill. The granular or
porous lumps of steel which are in a dry state will be crushed into coarser and
finer parts according to the hardness of the granules; the highest degree of
hardness produces the finest particles. This crushed steel is cleaned from
slag and cinder by means of a sieve or by washing, and is then sorted. If the
cleansing be done by washing, the material should be well and quickly dried

page_text: in order to have it in a pure state, and to prevent oxidation. The finer as
well as the coarser steel granules or crushed steel thus obtained are equally
suited for the manufacture of cast steel and refined or welding steel, namely,
1st., for cast steel by melting it in crucibles or pots in the ordinary manner,
and, 2nd., for refined or welding steel, by welding it in a welding furnace in
the following manner invented by me:-I place the crushed steel granules
into boxes or cases made of iron or steel, close the same from the access of air
by a cover of the same material, and put them thus prepared into a welding fur-
nace, where I subject them to a gentle welding heat. The steel being free from
slag and rust, then welds readily into a pure mass of steel, without sustaining
any further loss of carbon than that which the boxes, if of iron, may take up.
When these boxes or cases have reached a suitable welding heat they are
taken out of the furnace, and brought with their contents under the hammer.
After having been gently and carefully hammered on all sides they can be
formed into blooms, lumps, or ingots of any shape suitable for those purposes
for which the steel may be required.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Johann Carl Schemmann in the Great Seal Patent Office
on the 21st February 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHANN
CARL SCHEMMANN, of Hamburg, Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of August, in the year of our Lord One
thousand eight hundred and sixty-two, in the twenty-sixth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Johann Carl Schemmann, Her special licence, that I, the said Johann
Schemmann, executors, administrators, and assigns, or such others as I, the
said Johann Carl Schemmann, 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 "IMPROVE-
MENTS IN THE MANUFACTURE OF STEEL," upon the condition (amongst others)
that I, the said Johann Carl Schemmann, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said

page_text: 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 I, the said Johann Carl Schemmann, do hereby
declare the nature of my 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 :-
My Invention consists in operating upon iron in the puddling furnace, and
subsequently in manner hereafter described. When iron in the puddling
furnace reaches that point where the escape of carbonic oxide ceases, the
melted iron assumes a granular state. In this state the melted iron has lost
its properties as pig or raw iron, the greater portion of the carbon having
escaped, and part of the other heterogeneous substances commonly found in
iron having been volatilized or mixed with the slag. The iron in this state is
no longer pig iron, but has become purified iron containing a certain quantity
of carbon, and in this combination it is hard steel richly saturated with
carbon. On the metal being worked through still further under suitable
regulation of the furnace, every conversion beyond this granular state causes
a decrease of carbon in the metal until it will finally become iron. Between
each grade of further decarbonization the mass has become steel containing a
different amount of carbon, and is of a different degree of hardness, say from
the maximum to the minimum. Up to the present this fact has not been
sufficiently acknowledged, or rather no attention has been paid to discover a
process in order to obtain steel at the various stages of the decarbonization.
Now I commence to operate upon the iron as soon as it assumes the granular
state in the puddling furnace. On the mass reaching that granular state
which I consider fit for the particular kind of steel I desire to produce, I at
once shut off the draft in the furnace, open the door, and take the whole
mass out as quickly as possible and throw it into cold water, by which means
the steel hardens and gets rid of the slag and cinder.
'
It will need attention and experience to determine the right moment for
obtaining that particular kind of steel required, yet a pretty infallible guide will
be found in the appearance of the mass, and even if the right moment should
escape, steel will be produced suitable for some purpose. The more the mass
consists of isolated granules the greater is the amount of carbon it contains ;
and, again, the more these granules combine and weld together, the greater is
the decarbonization of the same, consequently the amount of carbon or the
bar 'n 'ss of the steel to be produced will depend on the choice of the moment,

page_text: or rather on the state in which the mass has been taken out of the furnace
and hardened. If, for instance, I take the mass out at that moment when the
granules have just formed, I obtain highly carbonized and extremely hard
steel with isolated grains. If the working or puddling of the mass be carried
on still further, carbon escapes and the grains begin to weld together, and the
higher the decarbonization the more the granules will unite and weld. If I
take the mass out of the furnace in the first state of welding of the granules
I obtain steel in granular, porous, sponge-like lumps. In each following state
these lumps come out in a more combined and less porous state, and the more
or less porous they are the more or less hard is the steel produced. The steel
thus made is fit for further working, simply by hammering it into pieces; but
I prefer to still better prepare it for further application and working by care-
fully crushing and reducing it under a stamp hammer or rollers, or in a mill.
The granular or porous lumps of steel which are in a dry state will be crushed
into coarser and finer parts according to the hardness of the granules, the
highest degree of hardness produces the finest particles. This crushed steel
is cleaned from slag and cinder by means of a sieve, or by washing, and is
then sorted. If the cleansing be done by washing, the material should be
well and quickly dried in order to have it in a pure state, and to prevent
oxidation. The finer as well as the coarser steel granules or crushed steel
thus obtained are equally suited for the manufacture of cast steel and refined
or welding steel, namely:-I. For cast steel by melting it in crucibles or pots
in the ordinary manner, and II., for refined or welding steel by welding it in
a welding furnace in the following manner invented by me :-I place the
crushed steel granules into boxes or cases made of iron or steel, close the same
from the access of air by a cover of the same material, and put them thus
prepared into a welding furnace, where I subject them to a gentle welding heat.
The steel being free from slag and rust then welds readily into a pure mass of
steel without sustaining any further loss of carbon than that which the boxes,
if of iron, may take up. When these boxes or cases have reached a suitable
welding heat they are taken out of the furnace, and brought with their
contents under the hammer. After having been gently and carefully ham-
mered on all sides, they can be formed into blooms, lumps, or ingots of any
shape suitable for those purposes for which the steel may be required.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that I claim as my improve-
ments in the manufacture of steel,-
First. manufacturing steel in a granular and spongy state by withdrawing

page_text: it from the puddling furnace at the stages herein-before described, and
plunging it in cold water.
Second, manufacturing refined steel by inclosing the granular steel obtained
as herein-before described, in iron or steel cases, submitting the same to
welding heat, and subjecting the cases and their contents to hammering, as
herein-before described.
In witness whereof, I, the said Johann Carl Schemmann, have here-
unto set my hand and seal, this Tenth day of February, One thousand
eight hundred and sixty-three.