IMPROVEMENTS IN THE MANUFACTURE OF INGOTS, SLABS, OR BLOOMS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office of
the Commissioners of Patents on the 31st December 1877. A communication
from abroad by Bernard Charles Lauth, of Pittsburgh, United States of
America.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN THE MANUFACTURE OF INGOTS, SLABS, OR BLOOMS."
A communication from abroad by Bernard Charles Lauth, of Pittsburgh, United
States of America.
This Invention relates to compound ingots, slabs, or blooms composed of different
metals or different qualities or grades of the same metal to be used for rails, armour
plates, heavy guns, and other purposes, and it consists in the employment in the
ingot mould of a fusible diaphragm or diaphragms, in order to temporarily separate
such different metals or different qualities or grades of metal of which the compound
ingot is composed.
The Invention is especially adapted to the manufacture of railway rails, in which
two or more malleable cast metals, or two or more qualities of the same metal are
required or desired in the finished rail, say, one metal or one quality in the head of
the rail, another in the base with either, or a third in the web, or with one in the
top wearing part of the head, the rest of the rail being of one or more other metals
or qualities of metals. The desirability of such a rail has long been recognized, but
a durable product of such character has not heretofore been found practically
attainable. Probably the greatest practical difficulty has been encountered in the
effort to secure an inseparable union between the different metals or qualities or
grades of metals employed, while at the same time keeping them so far distinct that
one shall not become seriously intermingled with the other. This difficulty is over-
come according to this Invention by casting the different metals or the different
qualities or grades of the same metal simultaneously in the same mould, but on the
opposite sides of a sheet metal diaphragm, which shall be so thin and of such degree
of fusibility as to become practically fused by and assimilated with the metals so
poured in, and permit a perfect union of the latter, but sufficiently durable to prevent
the metals or qualities of metal on its opposite sides from becoming commingled to
any great extent before they pass from a fluid condition.

page_text: The mould is of the usual or any suitable construction, such as may be adapted
to produce the shape of ingot desired preparatory to making the rail. At the proper
place in such mould, so that the space for the different metals or qualities of metals
may be suitably divided, there is arranged a thin sheet metal diaphragm, which is
secured in position in any convenient manner by lugs, grooves, or other device, or
with a two-part mould jointed at the proper place, the edges of the plate being
clamped in at the joint. In this manner the mould cavity is divided by a diaphragm
or diaphragms into the desired number of cells, two or more, according to the
number of metals or grades or qualities of metals desired in the finished rails, and
for this purpose either cast steel, Bessemer steel, or homogeneous iron, or any
qualities or grades of these metals or any of them capable of being cast and worked
may be used. These partitions being properly arranged, the different grades or
qualities of metal are poured simultaneously each into its appropriate cell so as to
produce a compound ingot, which, when worked down by hammering or rolling, or
both, shall give in the finished rail the proper or desired distribution of the metals.
The molten metals so poured in will rise simultaneously in the different cells, and
by the time the metal sets or loses its fluidity it will so far have effected a fusion of
the diaphragm as to result in a complete and perfect amalgamation or union of the
metals so poured in.
Preferably the partition sheets are so thin that they will be entirely or almost
entirely fused by the action of the molten metal, at the same time that the latter
becomes "set," or so far hardened that the different grades or qualities or kinds of
metal on opposite sides of such diaphragms will not commingle to any great extent,
but these diaphragms must be so thin that they will be substantially and to all
practical intents and purposes destroyed as separate component parts of the rail, or
so far diffused by and assimilated with the metals on its opposite sides that in the
rail produced each metal or quality or grade of metal will be united and solidified
with the next contiguous metal or grade or quality without the presence of an inter-
vening layer or stratum of unassimilated or unconverted material.
The thickness of such diaphragms will depend somewhat on the size and degree
of heat when the ingot is cast, for the greater the amount of molten metal employed,
and the higher its temperature, the thicker must be the diaphragms, or otherwise
they would be liable to fuse too soon, and allow the different metals or grades or
qualities of molten metal to run into each other and commingle.
The molten metal may be poured in at the top, or run in from the bottom into
the different cells, bottom pouring being preferred. After the ingot is thus made it
can be worked in any known way into the finished rail desired. By this process
there may be produced finished rails, in which a hard durable head or cap is
combined with a soft tough flange and web, and the relative degrees of each may be
varied at pleasure.
In applying the Invention to the manufacture of armour plates the armour ingot
is made in a similar manner to the ingots for rails.
In the case of heavy guns and similar bodies the diaphragm consists of a tube of
the requisite thickness.
It is obvious that two or more diaphragms may be used in carrying out this
Invention, according to the number of metals or qualities or grades of metal
employed.
When Bessemer steel of two grades is used it will be necessary to employ twọ
converters, one for the low grade of steel and the other for the higher grade. If
Martin-Siemens' open hearth furnaces are adopted, two of such furnaces are used for
a like purpose.