IMPROVEMENTS IN THE MANUFACTURE OR WORKING OF COMBINED IRON AND STEEL
Year: 1880

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields, in
the County of Middlesex, Gentleman, for an Invention of "IMPROVEMENTS
IN THE MANUFACTURE OR WORKING OF COMBINED IRON AND STEEL."
A communication from abroad by John Haldeman, of Brussells, in the
Kingdom of Belgium.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 25th October 1880.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MANUFACTURE OR WORKING OF COMBINED
TRON AND STEEL." A communication from abroad by John Haldeman, of Brussells,
in the Kingdom of Belgium.
This Invention, relating to the manufacture or working of combined iron and
steel, consists in first submitting a box or file of puddled or other iron which tightly
surrounds a core of steel (the steel being of any shape) and in any number of pieces)
to a very slow, soft, soaking heat until the steel is partially or completely molten,
and then in giving to the iron envelope a proper welding heat, and compressing the
whole under rolls or a hammer so as to obtain a new product, which combines both
the great tensile strength of the steel and the ductility of the iron, and which may
be worked in the same manner as and with greater facility than iron.
The enclosed steel may be alternated with layers of iron if desired. After the
steel has been partially or completely fused a strong quick heat is by preference
imparted in order to raise the iron to the requisite temperature for welding.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the 21st
April 1881.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MANUFACTURE OR WORKING OF COMBINED
IRON AND STEEL." A communication from abroad by John Haldemann, of
Brussells, in the Kingdom of Belgium.
Tho said Invention relates to an improved process of heating piles composed of a
steel core surrounded by an iron envelope in such a manner as to obtain a perfect
consolidation of the two metals.
Experience has shown that if composite piles are treated in the usual manner,
videlicet, by subjecting the piles to only a gradually increasing heat, the result
would in most cases be merely an ordinary weld, as the iron would usually be
brought to the proper heat before the steel could be molten, or if kept too long
under such heat the iron would burn.
In order to produce the proposed results my foreign correspondent has ascertained
that the two metals differing in nature and melting at widely different degrees of
heat should be brought to their respective points of fusion in such a manner that
the motion of the heat shall not interfere with the natural tendencies of the stcel
molecules to place themselves in equilibrium with the contracting iron molecules
and create a reciprocal attraction between the two metals. In order to accomplish
this the piles should be first heated so slowly that the heat can entirely penetrate
the steel degree by degree until the latter is partially, or, preferably, entirely
molten, and not high enough to injuriously affect the iron; and then, secondly, the
character of the heat should be changed and the iron envelope should be brought as
rapidly as possible to a white welding heat. The steel molecules will surrender a
small portion of their carbon to the iron molecules with which they are then
brought into such close contact, and they will fuse and blend together so intimately
that on both sides of the line of contact, and within a very limited space, the
change of nature from one metal to the other will shade down very gradually.
In practically carrying out the said Invention the piles are placed in a good iron
heating furnace, well heated and first worked with a closed damper, and heated so
slowly that the heat is kept at a point which will not injure the iron but will still
penetrate into the core of the steel degree by degree, and reduce it to a molten
condition. This forms the first step. The time required to do this will vary with
the size of the piles and the condition of the furnace, and it requires only the same
kind of experience as that which enables a good heater to ascertain the amount of
heat particular irons will bear. When this molten condition of the steel is attained
the second stage cominences, the damper is raised, and the piles are given as rapidly
as possible all the heat which the iron in the piles will bear until it is brought to a
high white welding heat. When brought to this state the piles are then subjected
to compression, either by hammer, rolls, or hydraulic pressure. The process is
completed, and the fusion is made so perfect that it is impossible to separate the
two metals at the point of union.
The use of rolls or hydraulic pressure is preferred to the hammer, because with
the first two if the piles are properly proportioned, and the two metals are each of
uniform width and thickness throughout their entire length and breadth, the
distinct lines and character of both metals will practically be maintained in uniforn
lines down to the smallest section.
A simple mode of making the piles or boxes is to shear puddle bars of the
requisite length and breadth for top and bottom pieces, then on the botton piece is
placed on edge two pieces, each one bent to a double right angle (this may be done

page_text: as the bars come from the rolls), sheared long enough to overlap, thus forming
bottom, sides, and ends of a box. In the centre is then placed sufficient steel to
fill it, the top is placed on, and the box wired is ready for the furnace. The steel
may be in one or many pieces, oxydized or not.
The expansion of the iron under heat will soon (if the puddle bars are rolled
true) make the envelope of iron sufficiently tight to protect the steel during heating
and hold it when molten.
It will readily be understood that any required specification for any use can be
met; for example, if the envelope is made of iron high in phosphorus and the steel
is low in carbon there is obtained a hard surface combined with great strength, as
required in rails, wagon tyres, and for many other uses; when very high tensile
strength, combined with safety under hot or cold treatment, as well as in service
is required, a steel high in carbon is employed, and an iron very ductile and fibrous.
These qualities are demanded in boiler plates, ship plates, bridge structures, and for
many other uses.
This product can be worked and welded precisely as iron, and is as safe in
working or service as the best iron, because the iron envelope must be broken fibre
by fibre to cause fracture.
The great value of a product uniting the marked and distinctively valuable
qualities of each metal, and so thoroughly fused as to become homogeneous in
structure, but preserving at the same time their distinctive lines, is so well known
as to need no elaboration. The difficulty has been to produce it perfectly uniforin
both in result and quality, and at a cost to make it commercially valuable.
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 hereinbefore in part
recited Letters Patent is,
The mode of heating piles or boxes composed of a steel core surrounded by an
envelope of puddled or other iron, videlicet, by first subjecting these piles to a low slow
heat, such as will not injuriously affect the iron, until the heat penetrates the whole
body of the steel degree by degree so as to reduce it to a partially or wholly molten
condition, and then, in the second place, changing the character of the heat so as
rapidly to bring the iron envelope to a high white welding heat, and then by com-
pression completing the process, thus producing an absolute fusion instead of a
weld of the two metals, substantially as and for the purpose herein before described.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification set my hand and seal, this Fourteenth day of April, One.
thousand eight hundred and eighty one.
J. HENRY JOHNSON. (L.S.)