IMPROVEMENTS IN THE MANUFACTURE OF COMPOUND PLATES APPLICABLE ALSO TO THE MANUFACTURE OF OTHER ARTICLES BY WELDING TOGETHER HARD AND SOFT IRON AND STEEL IN ANY DESIRED COMBINATION " PROVISIONAL SPECIFICATION
Year: 1883

page_text: Manufacture of Compound Plates, applicable also to the Manu-
facture of other Articles by Welding together Hard and Soft
LETTERS PATENT to Friedrich Alfred Krupp of Essen in the Empire of
Germany, Steel Manufacturer for an Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF COMPOUND PLATES APPLICABLE ALSO TO THE MANUFACTURE
OF OTHER ARTICLES BY WELDING TOGETHER HARD AND SOFT IRON AND
STEEL IN ANY DESIRED COMBINATION
"
PROVISIONAL SPECIFICATION left by the said Friedrich Alfred Krupp at
the Office of the Commissioners of Patents on the 3rd April 1883.
"E
FRIEDRICH ALFRED KRUPP of Essen in the Empire of Germany Steel
Manufacturer IMPROVEMENTS IN THE MANUFACTURE OF COMPOUND PLATES
APPLICABLE ALSO TO THE MANUFACTURE OF OTHER ARTICLES BY WELDING
TOGETHER HARD AND SOFT IRON AND STEEL IN ANY DESIRED COMBINATION"
In compound plates as heretofore manufactured from layers of hard and soft
steel and iron while uniting the hard material with the soft, and in the further
manufacture of the plates when in a heated condition, a considerable proportion of
the carbon passes from the hard to the soft layers.
The object of manufacturing compound plates is thus to a great extent
frustrated, furthermore difficulties arise in the manufacture because according to
conditions of temperature, more or less carbon passes into the soft layers so that in
many cases the requirements as to the amount of carbon to be contained in the
plates is not obtained.
Now according to my Invention I overcome this difficulty by welding between
the hard layers and soft layers of compound plates a thin layer of such metal,
metals or metallic alloys as will prevent or at any rate much impede the passing
of carbon from the harder into the softer layer.
Such or suitable metals and alloys of metals as will on the one hand much
impede the passing of the carbon whilst on the other hand will readily become
welded to iron or steel, or to chilled cast iron, are for instance Nickel, Cobalt and
highly silicious iron. I use by preference sheets or plates of nickel welded on both

page_text: sides to sheets or plates of iron and I thereby attain my object with a compara-
tively thin layer of nickel.
My Invention is applicable not only to compound plates but also to other articles
which are composed of hard and soft kinds of steel and iron and may be applied in
various ways.
As a rule however the conditions of temperature of the layers to be combined
with one another must be so chosen, that the intermediate layer is well welded
with the iron and steel but is nevertheless not melted.
The simplest method of making such a plate is to make the intermediate plate
as if it were a partition in a mould or form into which hard steel is poured at one
side of the intermediate plate whilst mild steel or homogeneous iron is poured in
simultaneously therewith at the other side.
If it is desired to avoid the pouring in of hard and soft metal at the same
time, then one material is first poured against one side of the intermediate plate
firmly fixed against the wall of the mould and then the other material is
poured against the other side of the intermediate plate after having brought the
congealed plate to a suitable temperature in a mould available for this second
casting.
If for instance the compound plate is to consist of annealed or puddled iron and
cast steel then the welded or annealed plate is made by forming one plate when it
is annealed for the last time from for example a sheet of nickel welded on both
Bides to sheets or plates of iron and then plating this side of the welded plate with
steel in any convenient manner.
The manner in which my process or invention must be modified when the plates
to be manufactured are to consist of several alternate layers of hard and soft
material is obvious from the foregoing description.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Friedrich Alfred Krupp in the Great Seal Patent Office on the
3rd October 1883.
FRIEDRICH ALFRED KRUPP, of Essen in the Empire of Germany, Steel
Manufacturer IMPROVEMENTS IN THE MANUFACTURE OF COMPOUND PLATES
APPLICABLE ALSO TO THE MANUFACTURE OF OTHER ARTICLES BY WELDING
TOGETHER HARD AND SOFT IRON AND STEEL IN ANY DESIRED COMBINATION
In compound plates as heretofore manufactured from layers of hard and soft
steel, and iron while uniting the hard material with the soft, and in the further
manufacture of the plates when in a heated condition a considerable proportion of
the carbon passes from the hard to the soft layers
The object of manufacturing compound plates is thus to a great extent frustrated
furthermore difficulties arise in the manufacture because according to conditions
of temperature more or less carbon passes into the soft layers so that in many cases
the requirements as to the amount of carbon to be contained in the plates is not
obtained
Now according to my invention I overcome this difficulty by welding between
the hard layers and soft layers of compound plates a thin layer of such metal,
metals or metallic alloys as will prevent or at any rate much impede the passing of
carbon from the harder into the softer layer.
Such or suitable metals and alloys of metals as will on the one hand much
impede the passing of the carbon whilst on the other hand will readily become
welded to iron or steel or to chilled cast iron are for instance, Nickel, Cobalt and
highly silicious iron. I use by preference sheets or plates of nickel welded on both
sides to sheets of iron and I thereby attain my object with a comparatively thin
layer of nickel.
My invention is applicable not only to compound plates but also to other articles
which are composed of hard and soft kinds of steel and iron and may be applied in
various ways
As a rule however the conditions of temperature of the layers to be combined
with one another must be so chosen that the intermediate layer is well welded with
the iron and steel but is nevertheless not melted.
The simplest method of making such a plate is to make the intermediate plate
as if it were a partition in a mould or form into which hard steel is poured at one
side of the intermediate plate whilst mild steel or homogeneous iron is poured in
simultaneously therewith at the other side.
If it is desired to avoid the pouring in of hard and soft metal at the same time
then one material is first poured against one side of the "intermediate" plate
which is firmly fixed against the wall of the mould.
The casting having congealed or set sufficiently and being of a suitable temperature
is then placed in another mould and the other material is then poured against the
other side of the intermediate plate.
If for instance the compound plate is to consist of annealed or puddled iron and
cast steel then the welded plate when it has been welded for the last time has for
its inside last layer welded to it for example a sheet of nickel having welded on
both its sides sheets of iron and then casting on the other side of the welded plate
a layer of steel in any convenient manner. Or the intermediate plate may be of
highly silicious iron,
The manner in which my process or invention must be modified when the plates
to be manufactured are to consist of several alternate layers of hard and soft
material is obvious from the foregoing description.

page_text: Having now described the nature of my said invention and in what manner the
same is to be performed I declare that I am aware that it has already years ago
been proposed and practised (especially in the manufacture of the metallic walls of
safes) to employ alternate layers of wrought iron and steel the iron plates being
placed in a mould with spaces between into which the molten steel is cast,
the mass so formed being afterwards rolled into a plate, but I declare that
I claim
First In the manufacture of all sorts of compound plates and other articles by
welding together hard and soft iron and steel the employment of intermediate
layers of such metals or alloys as shall prevent or impede the passage of carbon
from the hard to the soft iron or steel, substantially as set forth.
Second-The manufacture of compound iron or iron and steel plates and other
articles with intermediate layer or layers of nickel or cobalt to each side of
which has previously been welded sheet iron for preventing or impeding the passage
of the carbon from the hard to the soft iron or steel plate, substantially as set
forth.
Third The manufacture of compound iron or iron and steel plates and other
articles with intermediate layer or layers of highly silicious iron for preventing or
impeding the passage of the carbon from the hard to the soft iron or steel plate,
substantially as set forth
In witness whereof I the said Friedrich Alfred Krupp have hereunto set my
hand and seal this. twenty seventh day of August in the year of our Lord one
thousand eight hundred and eighty three.
FRIEDRICH ALFRED KRUPP (L.S.)