Improvements in the Process and Apparatus for Electrical Casting of Metals.
Year: 1890

page_text: Date of Application, 13th Oct., 1890
Complete Specification Left, 15th June, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
Improvements in the Process and Apparatus for Electrical Casting
of Metals.
I, NICHOLAS SLAWIANOFF, of Grosse Morskaia Strasse No. 15, St. Petersburg,
Russia, Mining Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to a new process of casting metals and metallic articles
or wares by means of an electric arc. Any metal or alloy may be employed for
casting, but the material should be in the form of rods or bars more or less long,
such as iron or steel rods, hoops &c., rolled or forged steel, pig iron or cast copper
alloys of various thickness, depending in respect of dimensions upon the strength
of electrical current and the size of the casting. Such a rod forms the one
electrode of a self regulating electrical are by the action of which it is rapidly
melted. The continuous melting moderates more or less the temperature of the
arc according to the fusibility of the melted electrode. This moderating of the
temperature is of advantage as thus is avoided the over-heating of the metal
which would result from the use of a carbon electrode. During the casting
operation one pole of the electrical machine is connected to the mould, the other
to the terminal of the automatic regulator, through which the current flows through
the melting-metal rod and thence through the arc into the mould. If the mould is
nou-conducting the pole can be connected to a carbon or preferably a metal rod
like that of the regulator, or thicker, placed in the mould so that the arc is formed
between the two rods until a certain quantity of melted metal has collected,
whereupon the arc is formed between the regulator rod and the fluid metal, while
the mould rod being in contact with the fluid metal rapidly melts, considerably
accelerating the operation and also lessening the burning of the metal.
L
It is not immaterial which pole of the machine is connected to the mould and
which to the regulator. For casting pig iron the positive pole should be connected
to the regulator which is the melting rod. In casting other metals the one pole or
the other is connected according to the result desired; thus, the part which is
desired to be most heated is to be connected to the positive pole which gives out
higher temperature. Moreover the positive and negative poles differ in respect of
their chemical action on the melted metal; for example if the melting rod of pig
iron is connected to the negative pole, a hard useless casting is the resuit.
The best material for moulds for pig iron and copper alloys is compressed coke,
for iron and steel the best is quartz sand with admixture of binding material.
Electrical casting cannot be carried on without means of regulating the length of
Any of the lamp regulators may be employed as automatic regulators, it
is only necessary to remove the one carbon holder, and to place in the other the rod
to be melted, and finally to provide the solenoid or electromagnet with a greater
number of coils.
the arc.
A
A simple substantial and practical regulator is represented in longitudinal and
transverse section by Figures 1 and 2 and in sectional plan by Figure 3. Its
arrangement is as follows. On a fulcrum pin O is pivotted a lever L which
carries a roller r engaged in a slot of a bar & connected to the horse shoe shaped
iron cores of the double solenoid S, which cores can move on three rollers r¹.
spring R fixed to the exterior casing of the regulator acts on the lever L to urge
the cores out of the solenoid. Each solenoid coil is one piece of copper tube
helically cut, so that no insulation is required and the coil can sustain considerable
heat. The lower end of the lever L is formed with an eye through which passes
an iron or steel tube T, capable of sliding to and fro in the eye unless held by the
setting screw W. Through the tube passes a spindle V carrying at one end a
hand wheel d for turning the spindle, and at the other end a grooved roller r" of
Pana

page_text: nara steel, against which another roller
this are two other rollers of which the one
mounted on a spring p².
is pressed by a strong spring. Below
is fixed in position and the other is
These four rollers serve to guide the melting rods a weight Q balances the rod
and its guides. On the tube T is a clanp 9 with a carbon rod the purpose of
which is hereafter explained, e is an iron shield through which the rod s passes
and which protects the roller guides from the heat and sparking of the metal.
In casting by aid of two regulators, as hereinafter described, a differential
regulator is employed. Figures 5, 6 and 7 represent the upper part of such
apparatus. It has four solenoids two wound with fine coils and two with thick
coils, with the cores in the form of H. The current in Figures 1, 2 and 3 takes
the following course, the conductor a the insulated clamp A the solenoid coil, the
framing the melting rod s, the are, the melted metal and the mould or the other
rod as indicated by Figure 4. When the differential regulator is used, one of the
ends of the fine coil is connected to A, the other end to A' which is connected to
the A clamp of the other regulator.
The regulator is operated as follows. It is suspended by a cord from A over
the mould, the conductors are properly connected, and the melting rod is put in
its place.
The operator taking the regulator in his left hand, turns the hand
wheel with his right until the melting rod touches the mould, whereupon the
solenoid draws in the core causing the arc to be struck, and the rod s begins to
melt, the drops of molten metal collecting in the mould. While the rod melts,
the are becomes so rapidly lengthened that, but for the regulator, it could not be
maintained. As the arc lengthens the current becomes weakened so that the
spring Rovercomes the attraction of the solenoid and the end of the tube T with
the melting rod s descends. At longer or shorter intervals the rod is to be
lowered by hand applied to the hand wheel d to turn the spindle V and roller
which involves no difficulty, as the regulator corrects manual emissions and the
arc is not interrupted. By the employment of the automatic regulator the current
can be taken direct from the dynamo machine without passing through accumulators.
In fact on suddenly closing a circuit of small resistance for a very strong current,
which in the preceding case is unavoidable, the difference of potential becomes
largely decreased, and casting by a current direct from the machine would be
impossible because the electric arc would cease immediately on beginning, as it
would on any alteration of current strength by the falling of a drop of the molten
metal, or the like, but the automatic regulator diminishes the length of the arc at
the proper time before its extinction.
The electrical casting can be carried out in any of the following wove

page_text: the difference of potential, and it is also useful to have exact information as to the
strength of current, these may be ascertained by means of any known ammeters
and voltmeters.
According to the above described process, not only moderate sized castings can
be cast, but also two pieces of metal may be united by casting metal into a space
between them. But the most important and extensive application of the process
consists in the improvement of cast and wrought pieces, by melting into blow holes
of pig iron and copper, into cracks, sand blows &c. in steel articles, and rents in
iron pieces, and the melting into defective parts of such articles, for which it is
useful and often necessary first to heat the piece that is to receive the molten metal.
When the part in which the metal is to be poured forms the mould one obtains the
metal in pure sound and soft condition.
In this case the metal which fills the mould plays the same part as the dead head
or runner in ordinary casting. A farther condition of a good casting is that it
should not be done in layers but in continuous mass the whole size of the mould.
Should the melting rod of the regulator be not enough to completely fill the space,
it might be lengthened without interrupting the casting process, for instance by
screwing on an additional length as shewn at y Figure 1. In most cases however
there is time to remove the part that may be burnt and to substitute a new rod.
The casting to fill blow holes in iron castings involves the greatest difficulties on
account of certain peculiarities which require attention. In the first. place it is to
be noted that not all kinds of pig iron are suitable for melting rods, a proper choice
has to be made. The rod must certainly be connected to the positive pole, but
nevertheless it happens that after the casting and the piece has been annealed and
when the casting is generally soft, at the border of the melted metal with the metal
into which it is poured, there is a certain hardening, the iron being white and hard.
If, in such cases, the piece has to be worked by tools, a farther operation has to be
done immediately after the casting and while the iron is still fluid, namely to slacken
the clamp W (Figures 1, 2 and 3), and to move the tube T so that the carbon in
the clamp Z is turned down so as to form between it and the fluid iron an arc
which is for some time maintained. No hardening will then be noticed and the pig
iron will be softer and richer in graphite the longer the heating by the electric arc
has been continued.
This results from the fact that the fluid iron becomes enriched by obtaining
graphite from the carbon rod. As is well known, more carbon passes from the
positive pole to the negative than from the negative to the positive, and this is
probably the reason for the enrichment of the iron with carbon when the carbon is
connected to the positive pole. When the contrary connection is made, very white
hard iron is the result. The above does not apply when iron articles are cast in
moulds that are not metallic, when such moulds are employed any pig iron can be
used, and even wrought iron can be cast provided that the mould is of coke, so that
the iron can become converted into pig by absorbing carbon from the mould.
Other, but less important applications of electrical casting might be mentioned.
The process might with advantage be used in the following cases.
1. Casting objects of moderate size in the usual way of any desired metal which
can be maintained by the process. The regulator has to act as the one electrode,
the crucible or the rod placed in it or the metal that collects in it has to serve as
the other electrode. This operation can also be used in special cases, as for instance
when an article has to be hurriedly cast and there is no furnace available, or when
on account of the smallness of the article it is not worth while to heat up a furnace.
2. Casting metals, alloys and substances which though conductors are highly
refractory, and cannot without great difficulty be melted by the usual methods.
3. Casting simultaneously several metals or alloys in certain proportions, for
which purpose, instead of a single rod in the regulator, rods. of the several
substances are placed so as to nielt together and fill the mould.
4. Casting, when alterations in the chemical conditions and physical properties
of the cast metal are desired.

page_text: Experiments show that (a) .brass, after electrical casting, becomes materially
altered chemically in consequence of the burning out of the zinc, and probably also
in its physical properties, colour, strength, etc. (b) Iron and steel after being run
through a carbon tube are converted into pig iron when cast in a coke mould, this
iron being so rich in graphite that it almost has the appearance of graphite, and
seems moreover to contain small portions of diamond for notwithstanding its
general softness some portion of its surface cut glass :-(c) When a thin layer of
the white hard pig iron has been melted and heated as above described by the
carbon electrode connected to the positive pole it changes into a fine soft grey iron
to the depth to which the melting extended in the casting operation.
This alteration is a source of a great advantage to electrical casting because this
process renders it possible :-(a) to cast parts of machines from any kind of iron,
even unsuitable kinds, such as scrap, the surface of the casting being softened by
the process :-( (b) to improve castings which have accidental hardening at the
junctions.
Dated this 12th day of
1000
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Process and Apparatus for Electrical Casting
of Metals.
I, NICHOLAS SLAWIANOFF, of Grosse Morskaia Strasse No. 15 St. Petersburg
Russia, Mining Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
This invention relates to a new process of casting metals and metallic articles
or wares by means of an electric arc. Any metal or alloy may be employed for
casting, but the material should be in the form of rods, or bars more or less long,
such as iron or steel rods, hoops &c. rolled or forged steel, pig iron or cast copper
alloys of various thickness, depending in respect of dimensions upon the strength
of electrical current and the size of the casting. Such a rod forms the one electrode
of a self regulating electrical are by the action of which it is rapidly melted. The
continuous melting moderates more or less the temperature of the arc according to
the fusibility of the melted electrode...
This moderating of the temperature is of advantage as thus is avoided the over-
heating of the metal which would result from the use of a carbon electrode.
During the casting operation one pole of the electrical machine is connected to
the mould, the other to the terminal of the automatic regulator, through which the
current flows through the melting metal rod, and thence through the arc into the
mould. If the mould is non-conducting the pole cau be connected to a carbon or
preferably a metal rod like that of the regulator, or thicker, placed in the mould
so that the arc is formed between the two rods until a certain quantity of melted
metal has collected, whereupon the arc is formed between the regulator rod and
the fluid metal, while the mould rod being in contact with the fluid metal rapidly
melts, considerably accelerating the operation and also lessening the burning of the
metal.
It is not immaterial which pole of the machine is connected to the mould and
which to the regulator. For casting pig iron the positive pole should be connected
to the regulator which is the melting rod. In casting other metals the one pole
or the other is connected according to the result desired; thus, the part which is
desired to be most heated is to be connected to the positive pole which gives out
higher temperature.
Moreover the positive and negative poles differ in respect of their chemical
action on the melted metal; for example if the melting rod of pig iron is connected
to the negative pole, a hard useless casting is the result.

page_text: The best material for moulds for pig iron and copper alloys is compressed coke,
for iron and steel the best is quartz sand with admixture of binding material.
Electrical casting cannot be carried on without means of regulating the length of
the arc. Any of the lamp regulators may be employed as automatic regulators, it
is only necessary to remove the one carbon holder, and to place in the other the
rod to be melted, and finally to provide the solenoid or electromagnet with a
greater number of coils.
Referring to the drawings accompanying my Provisional Specification a simple
substantial and practical regulator is represented in longitudinal and transverse
section by Figs. 1 and 2 and in sectional plan by- Fig. 3. Its arrangement is as
follows. On a fulcrum pin O is pivoted a lever L which carries a roller r engaged
in a slot of a bar k connected to the horse shoe shaped iron cores of the double
solenoid S, which cores can move on three rollers ¹. A spring R fixed to the
exterior casing of the regulator acts on the lever L to urge the cores out of the
solenoid. Each solenoid coil is one piece of copper tube helically cut, so that no
insulation is required and the coil can sustain considerable heat. The lower end of
the lever L is formed with an eye through which passes an iron or steel tube T,
capable of sliding to and fro in the eye unless held by the setting screw W.
Through the tube passes a spindle V carrying at one end a handwheel d for
turning the spindle, and at the other end a grooved roller of hard steel, against
which another roller is pressed by a strong spring. Below this are two other
rollers of which the one is fixed in position and the other is mounted on a
spring pl
These four rollers serve to guide the melting rods a weight balances the rod
and its guides. On the tube T is a clamp g with a carbon rod the purpose of which
is hereafter explained; a is an iron shield through which the rod s passes and
which protects the roller guides from the heat and sparking of the metal.
In casting by aid of two regulators, as hereinafter described, a differential
regulator is employed.
Figs. 5, 6 and 7 represent the upper part of such apparatus. It has four sole-
noids two wound with fine coils, and two with thick coils, with the cores in the
form of H.
The current in Figs. 1, 2, and 3 takes the following course, the conductor a
the insulated clamp A the solenoid coil, the framing the melting rod the
3,
arc, the
melted metal and the mould or the other rod as indicated by Fig. 4. When the
differential regulator is used, one of the ends of the fine coil is connected to A,
the other end to A' which is connected to the A clamp of the other regulator.
The regulator is operated as follows: It is suspended by a cord from A over
the mould, the conductors are properly connected, and the melting rod is put in its
place. The operator taking the regulator in his left hand, turns the hand wheel d
with his right until the melting rod touches the mould, whereupon the solenoid
draws in the core causing the are to be struck, and the rod begins to melt, the
drops of molten metal collecting in the mould.
While the rod melts, the are becomes so rapidly lengthened that, but for the
regulator, it could not be maintained.
As the arc lengthens the current becomes weakened so that the spring R over-
comes the attraction of the solenoid and the end of the tube T with the melting
rods descends. At longer or shorter intervals the rod is to be lowered by hand
applied to the hand wheel d to turn the spindle V and roller r", which involves no
difficulty, as the regulator corrects manual emissions and the arc is not interrupted.
By the employment of the automatic regulator the current can be taken direct from
the dynamo machine without passing through accumulators. In fact on suddenly
closing a circuit of small resistance for a very strong current, which in the
preceding case is unavoidable, the difference of potential becomes largely decreased,
and casting by a current direct from the machine would be impossible because the
electric arc would cease immediately on beginning, as it would on any alteration of
current strength by the falling of a drop of the molten metal, or the like, but the

page_text: extinction.
The electrical casting can be carried out in any of the following ways.
I. WITH A SIMPLE REGULATOR.
One pole a of the source of electricity is connected to the regulator, the
other pole is connected to the mould when it is a conductor, or with the molten
article Fig. 4 or with the carbon or metal rod, which is fixed in the handle Fig. 8
and introduced into the mould.
11. WITH TWO DIFFERENTIAL REGULATORS.
One pole a is connected to the binding screw of the one regulator and the other
pole with the like binding screw of the other regulator, and besides the binding
screw A for the fine coils is connected to the binding screw A of the other
regulator. In this way it becomes possible with the regulators to melt with two
arcs Fig. 9, or according to circumstances with one arc Fig. 10 the other acting as
conductor. The melting rod of the one regulator is connected to the positive pole
and the rod of the other to the negative pole. According as the one or the other
arrangement or both are adopted, various optical and chemical results are obtained.
In any case when a tolerably large rod of metal is melted, small pieces of metal
may be thrown into the fluid bath, which substantially promotes the operation and
lessens the heat. In melting, it is especially necessary to know the difference of
potential, and it is also useful to have exact information as to the strength of
current, these may be ascertained by means of any known ammeters and
voltmeters.
According to the above described process, not only moderate sized castings can
be cast, but also two pieces of metal may be united by casting metal into a space
between them. But the most important and extensive application of the process
consists in the improvement of cast and wrought pieces, by melting into blow holes
of pig iron and copper, into cracks, sand blows &c. in steel articles, and rents in
iron pieces, and the melting into defective parts of such articles, for which it is
useful and often necessary first to heat the piece that is to receive the molten metal.
When the part in which the metal is to be poured forms the mould one obtains the
metal in pure sound and soft condition.
In this case the metal which fills the mould plays the same part as the dead head
or runner in ordinary casting. A farther condition of a good casting is that it
should not be done in layers but in continuous mass the whole size of the mould.
Should the melting rod of the regulator be not enough to completely fill the space,
it might be lengthened without interrupting the casting process, for instance by
screwing on an additional length as shewn at y Fig. 1. In most cases however
there is time to remove the part that may be burnt and to substitute a new rod.
The casting to fill blow holes in iron castings involves the greatest difficulties on
account of certain peculiaritics which require attention. In the first place it is to
be noted that not all kinds of pig iron are suitable for melting rods, a proper
choice has to be made. The rod must certainly be connected to the positive pole,
but nevertheless it happens that after the casting and the piece has been annealed, and
when the casting is generally soft, at the border of the melted metal with the metal
into which it is poured, there is a certain hardening, the iron being white and hard.
If, in such cases, the piece has to be worked by tools, a further operation has to be
done immediately after the casting and while the irou is still fluid, namely to
slacken the clamp W (Figs. 1, 2 and 3) and to move the tube T so that the carbon
in the clamp Z is turned down so as to form between it and the Huid iron an arc
which is for some time maintained. No hardening will then be noticed and the
pig iron will be softer and richer in graphite the longer the heating by the electric
arc has been continued. This results from the fact that the fluid iron becomes
enriched by obtaining graphite from the carbon rod. As is well known, more

page_text: carbon passes from the positive pole to the negative than from the negative to the
positive, and this is probably the reason for the enrichment of the iron with carbon
when the carbon is connected to the positive pole. When the contrary connection is
made, very white hard iron is the result.
The above does not apply when iron articles are cast in moulds that are not
metallic, when such moulds are employed any pig iron can be used, and even wrought
iron can be cast provided that the mould is of coke, so that the iron can become
converted into pig by absorbing carbon from the mould. Other, but less important
applications of electrical casting might be mentioned. The process might with
advantage be used in the following cases.
1. Casting objects of moderate size in the usual way of any desired metal which
can be maintained by the process. The regulator has to act as the one electrode,
the crucible or the rod placed in it or the metal that collects in it has to serve as
the other electrode. This operation can also be used in special cases, as for
instance when an article has to be hurriedly cast and there is no furnace available,
or when on account of the smallness of the article it is not worth while to heat up
a furnace.
2. Casting metals, alloys and substances which though conductors are highly
refractory, and cannot without great difficulty be melted by the usual methods.
3. Casting simultaneously several metals or alloys in certain proportions, for
which purpose, instead of a single rod in the regulator, rods of the several substances
are placed so as to melt together and fill the mould.
4. Casting, when alterations in the chemical conditions and physical properties
of the cast metal are desired.
Experiments show that (a) brass, after electrical casting, becomes materially
altered chemically in consequence of the burning out of the zinc, and probably also
in its physical properties, colour strength etc. (6) Iron and steel after being run
through a carbon tube are converted into pig iron when cast in a coke mould, this
iron being so rich in graphite that it almost has the appearance of graphite, and
seems moreover to contain small portions of diamond for notwithstanding its
general softness some portion of its surface cut glass. (c) When a thin layer of
the white hard pig iron has been melted and heated as above described by the
carbon electrode connected to the positive pole it changes into a fine soft grey iron
to the depth to which the melting extended in the casting operation.
This alteration is a source of a great advantage to electrical casting because this
process renders it possible:-(a) to cast parts of machines from any kind of iron,
even unsuitable kinds, such as scrap, the surface of the casting being softened by
the process() to improve castings which have accidental hardening at the
junctions.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The herein described process of casting metals or alloys or altering their
properties, by producing a regulated electric arc, one of the electrodes of which is
a rod of the metal to be melted, the other being the mould or the metal melted
therein.
2. The modified process herein described, wherein two electric arcs are employed
subject to differential regulators.
3. For conducting the process above referred to electric current regulators and
apparatus constructed and arranged substantially as herein described with reference
to the accompanying drawings.
Dated this 15th day of June 1891
ABEL & IMRAY,
Agents for the Applicant.