Improved Means of Proventing Defects, such as Blow Holes and the like, in Castings by Electricity.
Year: 1890

page_text: Date of Application, 13th Oct., 1890
Complete Specification Left, 17th June, 1891-Accepted, 18th July, 1891
PROVISIONAL SPECIFICATION.
Improved Means of Proventing Defects, such as Blow Holes and
the like, in Castings by Electricity.
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 means of preventing defects in castings such as the
occurrence of blow holes cavities etc., by applying to metal that has just been cast
electrical action in order to obtain sound castings without blow holes, shrinkage,
runners or dead heads.
The process consists in maintaining in fluid condition or in heating the upper part
of the casting by heat produced by an electrical current, that is to say by an
electrical arc, or by passing the current through bad conductors such as slag,
whereby it is possible, as desired, not only to heat the casting, but also to add metal
to it, or to maintain only the upper layers of the casting into fluid condition until
the casting sets. In the first case the electric circuit would be closed by a rod of
metal near to the upper surface of the molten metal, this rod in melting adding to
the metal of the casting. In the latter case, the conductor still near to the surface
of the casting, is not of metal but of coke, graphite, molten slag and the like. In
both cases the action of the operation is to render possible the gradual setting of the
cast metal from below whereby (1) with metals that set quietly without bubbling,
the upper layer remaining fluid can serve until complete setting for filling hollows
resulting from shrinkage, and (2) with metals which bubble as they set, the upper
fluid layers, besides serving to fill shrinkage hollows, also allow escape of evolved
gases.
The application of this process to quietly setting metals has the advantage of
producing castings without shrinkage hollows, rendering feeding runners or dead
heads unnecessary, and the application of the process to metals such as iron and
steel, which bubble as they set has great importance, because it renders it easy to
obtain from such metals as pure iron and steel of all kinds, without addition of
chemical densifying agents such as aluminium, silicon &c. and without mechanical
pressure, completely sound castings, free from bubbles and serviceable to the outer-
inost layers. Almost the same results as those of the present process can be obtained
when casting parts of machines in suitable moulds, by introducing into the steel
aluminium or silicon and other such like hodies, but no method can rival the present
in cases where strength and homogeneity are necessary for castings of large steel
blocks as for manufacturing guns or armour plates, and for rolling. As is well
known, the waste in the usual steel casting processes in consequence of blow holes
and want of density in the upper parts of the ingots amounts often to one third, and
A steel
even more. No such waste occurs where the electrical process is used.
ingot electrically produced is equally good right through and its upper surface can
be quite flat without head to allow for shrinkage. The source of electricity
may be an accumulator battery or dynamo machine furnishing not less than 200
The one of the electrodes
to 300 ampères with a tension of not less than 50 volts.
is connected to a regulator of current intensity so that a current flows through the
conducting rod or the rod connected to the handle and thence into the molten
metal. The other electrode is connected either to the mould or to the molten metal,
or to another regulator and rod. In the two first cases, the densifying of the
casting is effected by an electrical arc or by the beating of the slag around the
easting, and in the latter case also by the heating of the slag in two places or by

page_text: two electrical arcs. The current regulator may generally resemble those of elec-
trical arc lamps, but it should be stronger as it has to be worked with powerful
currents; it should also be simple as it has to regulate the motion of only one of
the electrodes of the are and that within narrow limits.. Greater movements of the
electrode can be made by hand, the regulator correcting manual errors.
Figs. 1 and 2 of the accompanying drawings are vertical sections and Figure 3
is a plan of a regulator arranged to operate for the purposes above set forth. Two
pairs of solenoids S S coiled with large (fire proof) wire and S S with fine wire.
determine according to the strength of current and the elasticity of the spring R.
the proper position of the lever 1, which is pivotted at 0. To the lower arm
of L. is connected a sleeve through which a tubular rod V. passes. This rod
oscillates with the lever L. on its pivot 0. in obedience to the movements of the
solenoid cores, or it may be moved round 0. by hand applied to the handle M.
when the hand nut m is not screwed up. This latter movement is limited by the
circular slot n n at the lower end of the lever L. and enables the circuit to be quickly
opened, as is necessary towards the end of the operation while the upper layers of
the casting are setting. The weight. P. which counterbalances all the moveable
parts also serves to lessen the sensitiveness of the regulator, which result is attained
by the simultaneous straining of the spring R. by the screw and movements of the
weight P. towards the handle M. By slacking the screw e the tube V can be
moved longitudinally. The metal or carbon rods which acts as electrode of the
are can be lowered by hand and raised by the handle m', the worm we, worm
wheel k, spindle and grooved hard steel roller. The rod ss is pressed against
the roller by a spring and roller ", the movement of the rods is besides
being effected by, also effected by two rollers and which latter can he
pressed more or less against the rod by means of the screw and spring 7'. The
shield having a hole for passage of the rod s s protects the rollers froin heat and
sparking. On the tube V is fixed a sleeve D with two frames T T glazed with
coloured glass. (two red and one green glass form a suitable combination) to protect
the eyes and face of the operator from the injurious action of the electric light.
These frames can be moved along the tube V by the handle E. If the densifying
is carried on with one electrode only, no solenoid with fine coil is required and in
this case the iron core must have the form of (horse shoe) and not of H as
required for the above described differential regulator.
For carrying on the densifying operation the regulator must be suspended by a
chain or otherwise over the casting or ingot as shown in Fig. 4. The current takes
the following course, conductor A, clamp a, the large solenoid coils, the framing.
the clamp, the flexible conductor 7 clamp a", the instal or carbon rod s s the
molten slag. the molten metal and the conductor. If the operation is effected by
the use of two regulators the current flows from the molten metal to the rod s's
of the other regulator, and after passing the second regulator in the same way as
through the first, it returns to the source of electricity. In this case the con-
ductor is not necessary, but both the regulators must be differential; the course
of the shunt current is as follows, the clamp a of the first regulator, the small
conductor, the fine solenoid coils of the second regulator, and the clamp a of the
second regulator, the other shunt current taking a similar course.
If the block or ingot is cast in a cast iron mould as usual, the upper part of the
mould must be filled with refractory earthy material, as for instance, quartz sand
with admixture of binding material (Fig. 4). This is necessary because, other-
wise. the ingot, during the electrical operation, might become welded to the mould.
As the electrical operation has to be continued till the casting is quite set, it is
advisable with large ingots, to hasten the operation by cooling the lower part of the
mould with water.
Dated this 18th day of October 1890.
ABEL & IMRAY,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improved Means of Preventing Defects, such as Blow Holes and
the like, in Castings by Electricity.
I, NICHOLAS SLAWIANOFF of Grosse Morskaia No. 15 St. Petersburg, Russia.
Mining Engineer. do hereby declare the nature of this invention and in what
mauner the same is to be performed, to be particularly described and ascertained in
and by the following statement :-
This invention relates to means of preventing defects in castings such as the
occurrence of blow holes cavities etc. by applying to metal that has just been cast
electrical action in order to obtain sound castings without blow holes, shrinkage,
runners or dead heads.
The process consists in maintaining in fluid condition or in heating the upper
part of the casting by heat produced by an electrical current, that is to say by an
electrical, are, or by passing the current through bad conductors such as slag,
whereby it is possible, as desired, not only to heat the casting, but also to add metal
to it, or to maintain only the upper layers of the casting in fluid condition until
the casting sets. In the first case the electric circuit would be closed by a rod of
metal, this rod in melting adding to the metal of the casting. In the latter case,
the conductor still near to the surface of the casting, is not of metal but of coke,
graphite, molten slag or the like. In both cases the action of the operation is to
render possible the gradual setting of the cast metal from below whereby (1) with
metals that set quietly without bubbling, the upper layer remaining fluid can serve
until complete setting for filling hollows resulting from shrinkage, and (2) with
metals which bubble as they set, the upper fluid layers, besides serving to fill
shrinkage hollows, also allow escape of evolved gases.
The application of this process to quietly setting metals has the advantage of
producing castings without shrinkage hollows, rendering feeding runners or dead
heads unnecessary, and the application of the process to metals such as iron and
steel, which bubble as they set, has great importance, because it renders it easy to
obtain from such metals as pure iron and steel of all kinds, without addition of
chemical densifying agents such as aluminium, silicon &c. and without mechanical
pressure, completely sound castings, free from bubbles and serviceable to the
outermost layers. Almost the same results as those of the present process can be
obtained when casting parts of machines in suitable moulds, by introducing into the
steel aluminium or silicon and other such like bodies. but no method can rival the
present in cases where strength and homogeneity are necessary for castings of large
steel blocks, as for manufacturing guns or armour plates, and for rolling. As is
well known, the waste in the usual steel casting processes in consequence of blow
holes and want of density in the upper parts of the ingots amounts often to one
third, and even more. No such waste occurs where the electrical process is used.
A steel ingot electrically produced is equally good right through and its upper
surface can be quite fint without head to allow for shrinkage. The source of
electricity may be an accumulator battery or dynamo machine furnishing not less
than 200 to 300 amperes with a tension of not less than 50 volts. The one of the
electrodes is connected to a regulator of current intensity so that a current flows
through the conducting rod or the rod connected to the handle and thence into
the molten metal. The other electrode is connected either to the mould or to
the molten metal, or to another regulator and rod. In the two first cases, the
densifying of the casting is effected by an electrical are or by the heating of the
slag around the casting, and in the latter case also by the heating of the slag in
two places or by two electrical ares. The current regulator may generally resemble
those of electrical are lamps, but it should be stronger as it has to be worked with
powerful currents; it should also be simple as it has to regulate the motion of

page_text: only one of the electrodes of the arc and that within narrow limits.
Greater
movements of the electrode can be made by hand, the regulator correcting manual
errors.
Figs. 1 and 2 of the drawings accompanying my Provisional Specification are
vertical sections and Figure 3 is a plan of a regulator arranged to operate for the
purposes above set forth.
Two pairs of solenoids S S coiled with large (fire proof) wire and S S with fine
wire, determine according to the strength of current and the elasticity of the
spring R the proper position of the lever L which is pivotted at 0. To the lower
arm of L is connected a sleeve through which a tubular rod V passes. This rod
oscillates with the lever I on its pivot 0 in obedience to the movements of the
solenoid cores, or it may be moved round O, by hand applied to the handle M when
the hand nut is not screwed up. This latter movement is limited by the circular
slot at the lower end of the lever L and enables the circuit to be quickly
opened, as is necessary towards the end of the operation while the upper layers of
the casting are setting. The weight P which counterbalances all the movable
parts also serves to lessen the sensitiveness of the regulator, which result is attained
by the simultaneous straining of the spring It by the screw and movements of
the weight P towards the handle M. By 'slacking the screw the tube V can be
moved longitudinally. The metal or carbon rod s s which acts as electrode of the
are can be lowered by hand and raised by the handle m', the worm c, worm
wheel, spindle and grooved hard steel roller . The rod s s is pressed against
the roller by a spring and roller, the movement of the rod. ss is besides
being effected by ll, also effected by two rollers 11 and 11 which latter can be
pressed more or less against the rod by means of the screw 6" and spring p¹.
"
The shield having a hole for passage of the rods protects the rollers from
heat and sparking. On the tube Vis, fixed a sleeve D with two frames T T
glazed with colored glass, (two red and one green glass form a suitable combination)
to protect the eyes and face of the operator from the injuring action of the electric
light. These frames can be moved along the tube by the handle E. If the
densifying is carried on with one electrode only, no solenoid with fine. coil is
required and in this case the iron core must have the form of (horse shoe) and
not of Has required for the above described differential regulator..
For carrying on the densifying operation the regulator must be suspended by a
chain or otherwise over the casting or ingot as shown in Fig. 4. The current takes
the following course, conductor A, clamp a, the large solenoid coils, the framing,
the clamp the flexible conductor 1, clamp a", the instal or carbon rods the
molten slag, the molten metal and the conductor k.
If the operation is effected by the use of two regulators the current flows from.
the molten metal to the rod ss of the other regulator and after passing the second
regulator in the same way as through the first, it returns to the source of
electricity. In this case the conductor is not necessary, but both the regulators
must be differential; the course of the shunt current is as follows, the clamp a
of the first regulator, the small conductor ', the fine solenoid coils of the second
regulator, and the clamp a of the second regulator, the other shunt current taking
a similar course.
If the block or ingot is cast in a cast iron mould as usual, the upper part of the
'mould must be filled with refractory earthy material, as for instance, quartz sand
with admixture of hinding material (Fig. 4). This is necessary because, otherwise,
the ingot, during the electrical operation, might become welded to the mould. As
the electrical operation has to be continued till the casting is quite set, it is
advisable with large ingots, to hasten the operation by cooling the lower part of
the mould with water.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I claim :-
1. The berein described process for making good defects in metal castings by

page_text: subjecting the upper surface of the cast metal as it is setting to the heating action
of an electric are or of a resisted electric current applied through an electrode of
carbon or of the metal itself melting into cavities.
2. For conducting the process above referred to an electric current regulator and
apparatus constructed and arranged substantially as herein described with reference
to the accompanying drawings.
T
1
1741
C T
1001
ABEL & IMRAY,
Agents for the Applicant.