IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR CASTING STEEL
Year: 1884

page_text: PROVISIONAL SPECIFICATION.
I ALEXANDER MELVILLE CLARK of the firm of A. M. and W™ Clark of
53 Chancery Lane in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE PROCESS AND APPARATUS FOR CASTING STEEL" to be as follows :-
Notwithstanding the good results obtained from steel by mechanical tests it is
liable when used for objects of large dimensions to give way suddenly the reason
of which has not been determined.
These mysterious breakages may be attributed to imperfect casting of the ingot
from which the defective objects were made,
In the manufacture of cast steel only small ingots were at first cast for which a
clean surface was indispensable, and casting in small long ingot moulds of small
section answered very well for this purpose without presenting any difficulties.
The same method of working was afterwards applied to ingots of the largest
dimensions.
The general method is to place the ladle holding the liquid steel above the mould
so that the stream of steel falls vertically from the ladle into the ingot mould.
But for large ingots, this manner of casting is absolutely defective. Without
entering into detailed and lengthy explanations, the inconveniences of this mode of
working are,
1st No provision is made for the proper contraction of the metal when cooling.).
2nd The escape of the gas during solidification is impeded.
3rd An ingot is thus of necessity obtained, not homogeneous in chemical
composition and texture, and presenting transverse and longitudinal lines of
weakness the position and importance of which vary according to the nature of the
metal and the conditions under which the casting was performed. These
inequalities when very marked are the cause of the sudden subsequent breakages.
4th To obtain a perfectly satisfactory block of steel by this method of casting, a
very large portion of the upper side of the ingot must be sacrificed.
This Invention has for its object to remedy these defects which can be all
completely avoided by means of the arrangements for casting shown by way of
example in the annexed Drawings.

page_text: Figure 1 is a vertical central section of the general arrangement. Figure 2 is a
plan of the supporting bed of the ingot mould. Figures 3 and 4 are sectional
detailed views of the spoon or nose of the ladle.
The ladle g is carried by a crane, which ladle besides a raising, lowering, and
circular motion has also a reciprocating horizontal motion to and from the crane
pivot,
At the outside of the tapping hole of the ladle there is fixed a pipe a fitted at
its lower extremity with a nose or spoon 6 both made of refractory material. This
nose b is to change the direction of the stream by diverting it slightly upwards as
shown in Figure 1, instead of allowing it to fall vertically on the bottom of the 1
mould. The lower part of this nose is of a larger section than the tube itself so
that the velocity of the stream will be diminished when entering the ingot mould h
and prevent splashing at the commencement of the casting. The nose or spoon
shown on the Drawing can be arranged in any other way which attains the same
object. When the fall of the steel is considerable and the area of the tap hole of
the ladle and pipe great, the nose or spoon might be broken by the blow from the
falling steel and a bend or elbow would therefore be introduced and well supported
in the tube above the nose or spoon and with an enlargement below the bend.
The bottom of the ingot mould his formed of a plate of a good conducting metal
(copper for instance) 20 to 30 millimetres thick. This bottom rests on a
supporting frame of cast iron or other metal with radiating ribs, so close to each
other as to support the bottom plate and prevent it buckling under the weight of
steel. The ribs are of bracket form to allow room for a large rose e through which
water is discharged under pressure, in order to cool the bottom of the mould during
the process of casting. This plate can be thus kept so cool that there will be no
steam generated during the operation of casting.
The ribbed frame d is fixed on a foundation plate f slightly conical in the centre
for collecting the water and guiding it to the large central tube by which it is
carried away. A circular motion is imparted to the foundation plate, ribbed frame
and the ingot mould by bevel gear, the rose remaining fixed.
The apparatus works in the following manner.
The ladle containing the steel and the tap hole stopper being in position, the
tube a is fixed below the tap hole and the ladle is drawn over the mould and
lowered until the nose b is a few centimetres from the bottom of the mould. The
latter is then set in motion, the water is turned on and the tap hole plug is raised
to the full so that the flow of steel is abundant and in a few seconds covers the
bottom of the ingot mould. After this the flow of steel is lessened gradually, the
ladle is raised slowly, but not so quickly as the level of the steel rises, until the
flow of metal from the nose takes place at the very surface of the steel in
the mould. From this moment the ladle is raised at the same speed as the steel
rises in the mould so that the flow of molten steel will be always in the plane of
the surface of the molten metal. Moreover the flow of steel is regulated so that it
shall always be at a suitable temperature at the surface of the bath, and the ladle
can be moved backward and forwards so that the flow be more or less towards
the centre or the sides of the mould according to the purpose of the object to be
made from the ingot.
The casting ought to be so performed as to allow the steel to contract freely and
therefore it ought to be cooled from bottom to top as regularly as possible. For
hastening the cooling in the centre the holes in the middle of the rose are nearer
together than at the circumference, and the water from them strikes more.normally.
To facilitate the contraction at the periphery in certain cases, the interior of the
mould could be coated to a certain height with a light adherent refractory material
well dried.
When the bottom of the mould is once covered with liquid steel, the flow of
metal is moderated so that the cooling will be methodical upward and through the
metal; this is not only favourable to contraction but also to the escape of gas
which takes place during solidification. A very quick cooling by radiation is

page_text: produced by these arrangements at the surface of the bath in the ingot mould
during the running as fresh layers of liquid steel are poured on the preceding
already slightly cooled by radiation.
As the discharge orifice is always in part at least immersed in the liquid steel
the flow may be moderated in great measure and to protect this orifice from cold
the refractory material projects forward beyond or over it. The rotating motion
can be more rapid at the commencement, till the bottom of the mould is covered
with steel, but it must be so slow that the surface of the bath remains flat and
horizontal. There might be some fear in working with water in the casting pit;
but in this case it is as isolated from the pit and steel as that working the
hydraulic crane.
As this apparatus enables the casting to be so performed that the steel in the
centre of the ingot shall from the very commencement cool before the circumference,
large surfaces can be covered without the ingot having the cracks in the bottom
which are produced when casting by the ordinary method, ingots having a large
transverse section.
The bottom of the mould is well supported and the metal falls on it with very
little force, and in a different place at every moment and the plate is well cooled
below.
The right is reserved of applying to the mould a truneated cone shaped bottomn
of a good conducting metal, copper or cast iron &°. The thickness of this bottom.
increasing towards the centre would produce by its considerable mass a cooling
effect analogous to but not so effective as that produced by water. Remarkably
compact ingots are obtained by this process, the metal contracting freely and more
satisfactory results are obtained than by the most powerful compression. An ingot
no higher than its diameter will present no interior contraction, and can be all used
with security with the exception of the upper crust; the loss is thus reduced to a
minimum. By taking the necessary precautions an ingot as deep as an ordinary
ingot can be cast with much less contraction and a greater homogeniety than by any.
other processes. The ingots cast by this method are suited for objects of large
dimensions or where great security is required, e.g.: boiler and ship plates; large
crank shafts; screw shafts for steam vessels sections and bodies of cannons; railway
tyres.
The system is adapted for the production of cast steel armour and particularly
for compound armour produced by casting superimposed layers of steel of different
hardness.

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE PROCESS AND APPARATUS FOR CASTING STEEL" and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
Notwithstanding the good results obtained from steel by mechanical tests it is
liable when used for objects of large dimensions to give way suddenly, the reason
of which has not been determined.
These mysterious breakages may be attributed to imperfect casting of the ingot
from which the defective objects were made.
In the manufacture of cast steel only small ingots were at first cast for which a
clean surface was indispensable, and casting in small long ingot moulds of small
section answered very well for this purpose without presenting any difficulties.
The same method of working was afterwards applied to ingots of the largest
dimensions.
The general method is to place the ladle holding the liquid steel above the
mould so that the stream of steel falls vertically from the ladle into the ingot mould,
but for large ingots, this manner of casting is absolutely defective. Without
entering into detailed and lengthy explanations, the inconveniences of
working are,
1 No provision is made for the proper contraction of the metal when cooling.
2nd The escape of the gas during solidification is impeded.
3rd An ingot is thus of necessity obtained, not homogeneous in chemical
composition and texture, and presenting transverse and longitudinal lines of
weakness the position and importance of which vary according to the nature of the
metal and the conditions under which the casting was performed. These
inequalities when very marked are the cause of the sudden subsequent breakages.
4th To obtain a perfectly satisfactory block of steel by this method of casting, a
very large portion of the upper side of the ingot must be sacrificed.
This Invention has for its object to remedy these defects which can be all
completely avoided by means of the arrangements for casting shown by way of
example in the annexed Drawings.
Figure 1 is a vertical central section of the general arrangement of the apparatus.
Figure 2 is a plan of the supporting bed of the ingot mould. Figures 3 and 4 are
sectional detailed views of the spoon or nose of the ladle.
The ladle g is carried by a crane, which ladle besides a raising, lowering, and
circular motion has also a reciprocating horizontal motion to and from the crane
pivot.
At the outside of the tapping hole of the ladle there is fixed a pipe a fitted at
its lower extremity with a nose or spoon 6 both made of refractory material. This
nose b is to change the direction of the stream by diverting it slightly upwards as
shown in Figure 1, instead of allowing it to fall vertically on the bottom of the
mould. The lower part of this nose is of a larger section than the pipe itself so as
to diminish the velocity of the stream when entering the ingot mould h and
prevent splashing at the commencement of the casting. The nose or spoon shown
on the Drawing can be arranged in any other way which will attain the same
object. When the flow of steel is considerable and the area of the tap hole of the
ladle and pipe great, the nose or spoon might be broken by the blow from the

page_text: falling steel and a bend or elbow would therefore be introduced and well supported
in the tube above the nose or spoon and with an enlargement below the bend.
The bottom of the ingot mould h is formed of a plate of a good conducting, metal
(copper for instance) 20 to 30 millimetres thick. This bottom rests on a supporting
frame of cast iron or other metal with radiating ribs, so close to each other as to
support the bottom plate and prevent it buckling under the weight of the steel.
The ribs are of bracket form to allow room for a large rose e through which water
is discharged under pressure in order to cool the bottom of the mould during the
process of casting. The bottom plate can be thus kept so cool that there will be no
steam generated during the operation of casting.
The ribbed frame d is fixed on a foundation plate f slightly conical in the centre
for collecting the water and guiding it to the large central tube by which it is
carried away. A circular motion is imparted to the foundation plate, ribbed frame
and the ingot mould by bevel gear, the rose remaining fixed.
The apparatus works in the following manner: The ladle containing the steel
and the tap hole stopper being in position, the tube a is fixed below the tap hole
and the ladle is drawn over the mould, and lowered until the nose b is a few
centimetres from the bottom of the mould. The latter is then set in motion, the
water is turned on and the tap hole plug is raised to the full so that the flow of
steel is abundant and in a few seconds covers the bottom of the ingot mould.
After this the flow of steel is lessened gradually, the ladle is raised slowly, but not
so quickly as the level of the steel rises, until the flow of metal from the nose takes
place at the very surface of the steel in the mould. From this moment the ladle is
raised at the same speed as the steel rises in the mould so that the flow of molten
steel will be always in the plane of the surface of the molten metal. Moreover the
flow of steel is regulated so that it shall always be at a suitable temperature at the
surface of the bath, and the ladle can be moved backward and forwards so that
the flow be more or less towards the centre or the sides of the mould according to
the purpose of the object to be made from the ingot.
The casting ought to be so performed as to allow the steel to-contract freely and
therefore it ought to be cooled from bottom to top as regularly as possible. For
hastening the cooling in the centre the holes in the middle of the rose are nearer
together than at the circumference, and the water from them strikes more normally.
To facilitate the contraction at the periphery in certain cases, the interior of the
mould could be coated to a certain height with a light adherent refractory material
well dried.
When the bottom of the mould is once covered with liquid steel, the flow of
metal is moderated so that the cooling will be methodical upward and through the
metal; this is not only favorable to contraction but also to the escape of gas which
takes place during solidification. A very quick cooling by radiation is produced
by these arrangements at the surface of the bath in the ingot mould during the
running, as fresh layers of liquid steel are poured on the preceding layers already
slightly cooled by radiation.
As the discharge orifice is always in part at least immersed in the liquid steel
the flow may be moderated in great measure and to protect this orifice from. cold
the refractory material projects forward beyond or over it. The rotating motion
can be more rapid at the commencement, till the bottom of the mould is covered
with steel, but it must be so slow that the surface of the bath remains flat and
horizontal. There might be some fear in working with water in the casting pit;
but in this case it is as isolated from the pit and steel as that working the hydraulic
crane.
As this apparatus enables the casting to be so performed that the steel in the
centre of the ingot shall from the very commencement cool before the circumference,
large surfaces can be covered without the ingot having the cracks in the bottom
which are produced when casting ingots having a large transverse section by the
ordinary method.

page_text: The bottom of the mould is well supported and the metal falls on it with very
little force, and in a different-place at every moment and the plate is well cooled
below.
"
The right is reserved of applying to the mould a truncated cone shaped bottom
of a good conducting metal, copper or cast iron &. The thickness of this
bottom increasing towards the centre would produce by its considerable mass
a cooling effect analogous to but not so effective as that produced by water.
Remarkably compact ingots are obtained by this process, the metal contracting
freely and more satisfactory results are obtained than by the most powerful
compression. An ingot no higher than its diameter will present no interior
contraction, and can be all used with security with the exception of the upper
crust; the loss is thus reduced to a minimum. By taking the necessary precautions
an ingot as deep as an ordinary ingot can be cast with much less contraction and a
greater homogeneity than by any other processes. The ingots cast by this method
are suited for objects of large dimensions or where great security is required, e.g. ;
boiler and ship plates; large crank shafts; screw shafts for steam vessels, sections
and bodies of cannons; railway tyres &°.
The system is adapted for the production of cast steel armour and particularly
for compound armour produced by casting superimposed layers of steel of different
degrees of hardness.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, I declare that what
I claim is
b
1 In the manufacture of cast steel, the employment of a nose or spoon 6 for
projecting the molten lead into the ingot mould from the ladle in a horizontal
or nearly horizontal direction as and for the purpose specified.
2nd The combination with the ladle, of a pipe a having a nose or spoon b of
larger section than said pipe to reduce the velocity at which the stream of molten
metal enters the mould.
•
3rd The combination with the ingot mould h of the ladle g provided with a pipe
for supplying the molten steel, said ladle having a rising motion so as to enable the
point of delivery of the molten metal to be maintained at or about the surface of
the bath as specified.
4th Imparting rotary motion to the ingot mould so as to direct the jet of molten
metal towards the various parts of the bath, as described for the purpose specified.
5th The construction of revolving ingot mould for casting steel consisting (a) of
a mould box lined with refractory material (b) a bottom plate c of sheet metal
forming a good conductor (c) a metal frame d with radial ribs supporting the
bottom plate c (d) a fixed rose e for discharging water under pressure against the
bottom plate c for the purposes of cooling (e) a foundation plate f provided with a
central water discharge and bevel gearing for imparting rotary motion to the
ingot mould all arranged and combined as herein before described for the purpose
specified.
1004