IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL
Year: 1871

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL."-A com-
munication from abroad by William Sellers, of the City and County
of Philadelphia, in the State of Pennsylvania, United States of
Amonian
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition,
on the 25th November 1871.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF IRON AND STEEL," a
communication to me from abroad by William Sellers, of the City and

page_text: County of Philadelphia, in the State of Pennsylvania, United States of
America, to be as follows:-
This Invention relates to certain improvements in the manufacture of
iron or steel from the puddle ball, or from wrought-iron scrap, or steel
scrap; and comprises a novel method of treating puddle balls, or i
wrought-iron scrap, or steel scrap so as to produce in a shorter way and
with less machinery than has heretofore been employed a better iron
than has hitherto been derived from these materials; and the said
Invention comprises the production of such iron from puddle ball alone,
or from wrought-iron scrap alone, or from steel scrap alone, or from
wrought-iron scrap and steel scrap, or from puddle ball and wrought-iron
scrap, or from puddle ball and steel scrap, without using the cinder bath
or the cast-iron bath which has hitherto always formed a constituent of
the charge in this manufacture. The said Invention further comprises a
novel mode of treating this new product with spiegel eisen, or manganese,
or other equivalent for the purposes herein-after described.
The object of the said Invention is to purify iron without subjecting
it to any of the piling and welding processes heretofore employed for that
purpose, and before it is subjected to any of the working by which it is
brought into forms or shapes, or before it is subjected to any subsequent
treatment for the formation of steel or other modifications of iron; and
this Invention consists in first puddling the pig iron and then melting
the puddled ball, that is, in order to purify the metal after it has been
puddled a melting operation is substituted for the welding process here-
tofore employed, with its attendant squeezing or hammering, piling, and
rolling operations, thus not only dispensing with these operations, 'but
attaining at a single step a degree of purity to which the iron has never
heretofore been brought by these several steps of treatment.
By combining the puddling and melting operations in place of
puddling and welding the conditions required in the puddling process
are simplified, and mechanical puddling becomes more feasible, as
impurities that may become incorporated with the puddle ball will,
when that ball is melted, be at once discharged instead of being
retained within it, and more intimately blended with it by squeezing,
hammering, or rolling. By this improved process the iron is brought
more rapidly to the advanced stage of purity at which it can be treated
for conversion into steel, and the range of materials from which steel can

page_text: be produced is thus greatly extended, the iron being more effectually
purified during the operation of puddling than it can be when melted
without puddling, whilst by first puddling and then melting the puddle
ball the iron is brought as already explained to a state of purity not
attainable by means of all the usual steps of treatment combined, and
this without sacrificing the facility with which any desirable material
may be added to the molten mass to improve its quality or to modify
its character, and retaining all facilities for testing its quality before
casting.
The Inventor is aware that puddle balls have been put in the place of
wrought iron as a charge in the production of steel upon the open
hearth, this charge being added in the same order relatively to the
preceding charges, the first of which was pig iron, as wrought iron is
usually added in this operation; but it is the object of this Invention to
avoid this charge of pig iron on account of the impurities which it
ordinarily contains, and in the improved process it is unnecessary to
have any such base.
Furthermore the wrought-iron and steel scrap which are essential
elements in the production of steel upon the open hearth as last
described, are entirely unnecessary to the improved process, but not
incompatible with the practice thereof, and may for economical con-
siderations be used when desired in connection with the puddle ball,
or the whole charge may consist of either or of any or of all these
three.
In carrying out the said Invention it is preferable to transfer the
puddle ball directly from the puddling furnace to the melting furnace,
and if scrap be used either with the puddle ball or alone, to primarilarily
heat the scrap in a muffle connected with the melting furnace, or to
otherwise heat it in another furnace, from which it is transferred directly
to the melting furnace, and the charge is simply brought to a molten
state as in melting cast iron, care being taken however to use a non-
oxydising flame.
The Inventor has found the condition of the iron thus melted when it
first falls into one mass to be what is designated as "mushy," and by
continuing the heat it becomes pasty. As the charge when brought to
this condition by the improved process is too soft for general purposes
there is added to the charge when in the "mushy" state a small per-

page_text: centage of pig iron, or spiegel, or other equivalent to modify its
character and facilitate its removal from the melting furnace either into
moulds or into a ladle. If desired there may also be added at this stage
any larger proportion of the above or of other foreign matters which may
be found desirable or expedient for the further purposes of modifying
the character of the metal or for adapting it to special uses in special
cases, but the addition of the ascertained and well-known per-centage of
spiegel, or manganese, or other equivalent for the purpose of bringing
the metal from the "mushy "state to a fluid condition is the essential
feature of this part of the Invention. This per-centage will vary with
the proportion of carbon contained in the material so added, and also
depends somewhat upon the heat of the furnace, but will range from two
to ten per cent. of the whole charge.
Within these limits the precise quantity for any particular charge
will be readily determined by the technical knowledge and skill of the
manager or conductor of the works.
The ordinary or other suitable puddling furnaces worked either by
hand or by mechanical means, and the usual melting furnaces, may
be employed in carrying out the above-described Invention, but the
Inventor prefers to employ in the puddling process the peculiar puddling
machine for which Provisional Protection was granted on his behalf to
the said John Henry Johnson, bearing date the Third of October One
thousand cight hundred and seventy-one, Number 2612.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent 2
Office on the 25th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters a
Patent, bearing date the Twenty-fifth day of November, in the year
of our Lord One thousand eight hundred and seventy-one, in the 35th
year of Her reign, did, for Herself, Her heirs and successors, give and

page_text: grant unto me, the said John Henry Johnson, Her special license that
I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, my executors,
administrators, or 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 THE
Manufacture of IRON AND STEEL," a communication to me from abroad by
William Sellers, of the City and County of Philadelphia, in the State of
Pennsylvania, United States of America, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or adminis-
trators, by an instrument in writing under my hand and seal, 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 I, the said John Henry Johnson, do hereby
declare the nature of the 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 :-
-
The said Invention relates to certain new and useful improvements in
the manufacture of iron or steel from the puddle ball, or from wrought-
iron scrap, or steel scrap.
My improvement comprises a novel method of treating puddle balls,
or wrought-iron scrap, or steel scrap so as to produce in a shorter way
and with less machinery than has heretofore been employed a better iron
than has hitherto been derived from these materials; and my Invention
comprises the production of such iron from puddle ball alone, or from
wrought-iron scrap alone, or from steel scrap alone, or from wrought-
iron scrap and steel scrap, or from puddle ball and wrought-iron scrap,
or from puddle ball and steel scrap without using the cinder bath or the
cast-iron bath which has hitherto always formed a constituent of the
charge in this manufacture; and my improvements further comprise a
novel mode of treating this new product with spiegel eisen, or man-
ganese, or other equivalent for the purposes herein-after to be fully
described.

page_text: Heretofore in carrying forward the manufacture of iron which has
been brought to the stage of puddle ball the practice has been to
hammer or squeeze this ball into a bloom, and immediately pass this
bloom through a pair of rolls so as to reduce it to a flat bar, known in
the trade as muck or puddle bar.
piles" of suitable size for the product desired, having been first cut
into proper lengths.
66
These bars are next formed into 5
To make what is known in the market as "refined iron," the "piles"
formed as above are heated and rolled into "slabs" or broad flat bars,
and these slabs are cut and piled for re-working in the manner described 1
for muck bars. This secondary pile is then re-heated and rolled into the
finished product ready for the market. In this process of manufacture
the iron is three times rolled, and allowed to cool twice in its transition
from the puddle ball to the finished bar.
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In making what is known in the market as common bars," and in 1
making common railroad bars," the finishing pile is formed with the
top and bottom slabs only of iron made by pilling and rolling the puddle
bars, whilst the interior of this pile is composed of puddle bars.
On the other hand, in making shaped irons, as H beams, Channel
bars, T iron, &c., the finishing pile from which these are formed is com-
posed of iron which has been treated in the manner described for refined
iron, so that with this character of product the iron is thrice piled, four
times rolled, and thrice cooled in its transition from the puddle ball to
the finished product.
Aside from any economical considerations, such as loss of heat in
cooling, the manipulation in cutting and piling crop, ends, &c., there is
the difficult necessity in this practice of insuring a perfect union of all
the parts composing the various piles. This cannot be done so long as
certain impurities remain between these parts, such as the waste
products of combustion from the furnace and the oxides of iron which
form upon the surfaces at each cooling of the parts which compose the
piles.
Practically it is impossible in this process to remove these impurities,
and iron thus manufactured will exhibit the lines of junction if a section
of the bar is made, and this section polished and examined with a
microscope or treated with acid, and in fact many of these lines will be
clearly discernible with the naked eye, so that the finished product will

page_text: be composed of laminæ, and in no proper sense homogeneous. These
defective joinings are the lines upon which the material will separate when
subjected to crushing, or to irregular transverse or torsional strains, or to
rolling action under a load, as for example in railroad bars, which when
formed as in the process above described will "laminate" under this
action, and these strains, all of which are incident to their use, that is to
say, the heavy rolling action, causes such railroad bars to separate where
they have been imperfectly joined.
As these defects are due to the presence of impurities in the iron it
has been attempted to remedy them by making the puddle ball of such
size that the finished product might be made from this ball without
subsequent piling, but aside from the difficulty of producing such a ball
in the first instance, it must be observed that when the iron is in this
(puddle ball) state it contains a large amount of cinder, which can only
be removed by subsequent working, and the difficulty in effecting this
purification is increased very greatly with the increased size of the ball.
The size of the puddle ball being limited by the ability of the workman
to handle it when the balling in the puddling furnace is performed by
hand, various mechanical appliances have been resorted to for the
purpose of reducing the cost of this process, as well as of increasing the
size of the puddle ball beyond the limits of manual strength, but it must
be evident that if the production of a large puddle ball should be suc-
cessfully accomplished by the aid of machinery, its size must still be
limited by our ability to drive out its impurities by subsequent working,
for whenever the size of the ball has been increased to an unusual
extent the material composing it is more irregular in quality and the
danger of enclosing within it foreign matters from the lining of the
furnace is increased, so that the piling and welding process has here-
tofore been relied upon and resorted to for removing these impurities
from the puddle ball.
In the manufacture of steel various processes have been more or less
followed, such as the cementation, the crucible, the Bessemer, and the
open hearth, the latter being nearly allied to the crucible. In the
crucible process steel scrap and wrought-iron scrap, or steel scrap,
wrought-iron scrap, and cast iron (in varying proportions according to
the quality of the materials and the desired product), are melted together
with a small per-centage of manganese, and when thoroughly liquid the
contents of the crucible are poured into a mould, or the contents of
.

page_text: a number of crucibles are poured into a ladle, from which they are
tapped into a mould; but there is no means in this process of purifying
the metal after it is melted, the quality of the product being dependent
upon the materials placed in the crucible at the commencement of the
operation and constituting the charge.
In the open hearth process the materials to compose the casting are
charged into the furnace from time to time during the heat and the
manganese is added at the latest stage. The materials are nearly the
same as in the crucible process, but as the iron can be purified to a
limited extent, more pig iron can be used in this process than in the
crucible, but in both the atmospheric air is excluded from contact with
the metal.
The Bessemer process, on the contrary, is dependent upon an intimate
mixture of the air with the molten metal, which is thereby decarbonized
and also purified to a limited extent, but as yet it has been found
impossible to remove by this process certain impurities which are readily
disposed of in puddling, so that the production of steel by this method
is only practicable with certain qualities of pig iron, but still this is the
only method by which the pig iron has as yet been converted directly
into steel without the admixture of wrought iron or steel during the
operation. Moreover in this as in the crucible and open hearth pro-
cesses, the quality of the product is dependent upon the materials first
placed in the furnace, but unlike the open hearth process this method
affords no means of testing the quality of the metal before the cast is
made.
It is not to be inferred from the foregoing that the character of the
product will not in every case depend to some extent upon the quality
of the materials used, but only that the means of purification are so
limited in any of the processes heretofore employed in the manufacture
of steel that the range for selection of materials is much more limited
than in the manufacture of iron.
It is well known that between low steel and the wrought iron of
commerce the difference in carbon is very small, in fact the best boiler-
plate steel contains less carbon than many of the irons which are sold in
the market; the one has the characteristics of steel, the other of iron,
and these characteristics are very marked. I have discovered that this
characteristic difference is not so much due to the presence or absence

page_text: of carbon as to the process of manufacture. In the one the metal is
free from impurities and the crystal is perfectly formed after melting,
whilst in the other the heat has never been sufficient to melt the iron
and the perfect crystal has never formed, whilst impurities mechanically
mixed permeate the mass. The object of this Invention is to conduct
the manufacture of iron so that perfect crystallization will always be
obtained, and with this view to purify iron without subjecting it to any
of the piling and welding processes heretofore employed for that purpose,
and before it is subjected to any of the working by which it is brought
into forms or shapes, or before it is subjected to any subsequent treat-
ment for the formation of steel or other modifications of iron; and my
Invention consists in first puddling the pig iron and then melting the
puddled ball, that is, in order to purify the metal after it has been
puddled I substitute a melting operation for the welding process here-
tofore employed, with its attendant squeezing or hammering, piling, and
rolling operations, thus not only dispensing with these operations, but
attaining at a single step a degree of purity to which the iron has never
heretofore been brought by these several steps of treatment.
By combining the puddling and melting operations in place of
puddling and welding, the conditions required in the puddling process
are simplified and mechanical puddling becomes more feasible, as
impurities that may become incorporated with the puddle ball will,
when that ball is melted, be at once discharged instead of being
retained within it, and more intimately blended with it by squeezing,
hammering, or rolling. By this process the iron is brought more rapidly
to the advanced stage of purity at which it can be treated for conversion
into steel, and the range of materials from which steel can be produced
is thus greatly extended, the iron being more effectually purified during
the operation of puddling than it can be when melted without puddling,
whilst by first puddling and then melting the puddle ball the iron is
brought, as already explained, to a state of purity not attainable by
means of all the usual steps of treatment combined, and this without
sacrificing the facility with which any desirable material may be added
to the molten mass to improve its quality or to modify its character, and
retaining all facilities for testing its quality before casting.
I am aware that puddle balls have been put in the place of wrought
iron as a charge in the production of steel upon the open hearth, this
charge being added in the same order relatively to the preceding

page_text: charges, the first of which was pig iron, as wrought iron is usually
added in this operation; but it is the object of my Invention to avoid
this charge of pig iron on account of the impurities which it ordinarily
contains, and in this process it is unnecessary to have any such base.
Furthermore the wrought iron and steel scraps which are essential
elements in the production of steel upon the open hearth as last
described, are entirely unnecessary to this process, but not incompatible
with the practice thereof, and may for economical considerations be used
when desired in connection with the puddle ball, or the whole charge
may consist of either, or of any, or of all these three.
In the practice of this Invention, and in the use of the above-
described improvements, it is preferable to transfer the puddle ball
directly from the puddling furnace to the melting furnace, and if scrap
be used either with the puddle ball or alone, to preliminarily heat the
scrap in a muffle connected with the melting furnace, or to otherwise
heat it in another furnace, from which it is transferred directly to the
melting furnace, and the charge is simply brought to a molten state as
in melting cast iron, care being taken however to use a non-oxydising
flame.
In the practice of this Invention and improvements I find the con-
dition of the iron thus melted when it first falls into one mass to be
what is designated as "mushy," and by continuing the heat it becomes
pasty. As the charge when brought to this condition by this process is
too soft for general purposes I add to the charge when in the "mushy"
state a small per-centage of pig iron, or spiegel, or other equivalent to
modify its character and facilitate its removal from the melting furnace
either into moulds or into a ladle. I contemplate further adding at this
stage any larger proportion of the above or of other foreign matters
which I may find desirable or expedient for the further purposes of
modifying the character of the metal or for adapting it to special uses in
special cases. It is impossible for me to designate herein either the
materials or the proportions which I propose to thus employ, but it is
unnecessary for me to do so, as I do not now claim more than the
addition of the ascertained and well-known per-centage of spiegel, or
manganese, or other equivalent for the purpose of bringing the metal
from the mushy state to a fluid condition. This per-centage will vary
with the proportion of carbon contained in the material so added, and

page_text: also depends somewhat upon the heat of the furnace, but will range from
two to ten per cent. of the whole charge.
Within these limits the precise quantity for any particular charge
will be readily determined by the technical knowledge and skill of the
manager or conductor of the works.
I may here observe that the ordinary or other suitable puddling
furnace worked either by hand or by mechanical means, and also any
melting furnace which is capable of producing the requisite intensity of
flame without free oxygin, may be employed in carrying out the above-
described Invention%; but the melting furnace for which I obtained
Letters Patent, bearing date the Eighth of January One thousand eight
hundred and seventy-two, No. 59, will be found to answer best.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. The novel method herein described of treating iron or steel by
melting it without the use of a bath.
Secondly. The novel method herein described of purifying iron by first
puddling and then melting it as described.
Thirdly. The novel method herein described of treating a charge con-
sisting only of puddle ball, or of wrought or steel scrap, or of any or
either of these three, without the use of a bath, and adding spiegel,
manganese, or other equivalents, for the purposes described.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, the Twenty-third day of
Munth
1