Improved Method of and Apparatus for Hardening or Tempering Steel Plates and other Articles.
Year: 1894

page_text: Date of Application, 27th Feb., 1894
Complete Specification Left, 4th Aug., 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
Improved Method of and Apparatus for Hardening or Tempering
Steel Plates and other Articles.
We, HUGH WILLIAM GABBETT FAIRFAX, of St. George's Club, Hanover
Square, in the County of Middlesex, Civil Engineer and WILLIAM BEARDMORE
of Parkhead Forge, near Glasgow, Steel Manufacturer, do hereby declare the
nature of this invention to be as follows:-
This invention has for its object to provide an improved method of and apparatus
for hardening or tempering steel plates and other metab articles.
The chief feature of our said invention consists in the utilization for chilling or
cooling and hardening the articles to be treated of a medium which has been
reduced to a low temperature by artificial cooling means.
Another important feature of our said invention consists in applying pressure
to the article while undergoing treatment in accordance with our method of
cooling.
In carrying our invention into effect we prefer to use for chilling the plate or
other article a liquid which as before indicated has been cooled to a low tempera-
ture by a freezing mixture or by chemical or other suitable artificial cooling means,
as for instance carbonic acid, or ammonia, which by its volatilization and consequent
expansion will produce cold. The plate or other article may, after being heated to
the proper temperature, be conveniently placed and suitably supported in a box or
the like through which the chilling liquid is passed. By this treatment the article
is rapidly chilled and hardened. The length of time to which the article will be
subjected to the cooling medium will of course depend on its thickness and on the
degree of hardness to be obtained. A convenient mode of introducing and with-
drawing the cooling liquid is by means of perforated or slotted pipes arranged at
the top and bottom of the box. In some instances the liquid may not require
to be circulated, the articles to be treated being in such instances merely immersed
therein.
In case a solidified or partially solidified cooling medium is used, the same is
arranged to make contact with the faces of the plate or other article to be treated.
Mixtures of snow and potash, or snow and calcium chloride crystallized, or snow or
pulverized ice and dilute sulphuric acid, form very useful chilling media. Whether
the chilling medium be liquid or solidified, pressure may or may not be applied
thereto as may be desired, during the chilling operation. The chilling operation
may be effected on metal in the molten state, in which case it is conducted in a
suitable mould which mould is jacketed and the chilling medium circulated therein,
or the mould may be surrounded by pipes through which the chilling medium is
circulated, or which are filled with the chilling medium. Or the mould may be
immersed in a vessel which contains the freezing or chilling medium, or in other
words, may be surrounded by such chilling medium. Under certain circumstances
it may be advisable that all or a part of the molten metal should come in actual
contact with the freezing mixture as for instance the bead or front end or point
of a projectile to ensure greater hardness, either with or without pressure, but
preferably the former.
In some instances the plate to be chilled is separated from the chilling medium
by a thin plate so as to prevent actual contact therewith. For flat plates we
prefer to chill both sides simultaneously to prevent warping. A curved plate

page_text: may be obtained by chilling the same
the other.
Dated this 23rd day of February 1894.
more severely on one side than on
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W:C., Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Method of and Apparatus for Hardening or Tempering
Steel Plates and other Articles.
We, HUGH WILLIAM GABBETT-FAIRFAX, of St. George's Club, Hanover
Square, in the County of Middlesex, Civil Engineer, and WILLIAM BEARDMORE,
of Parkhead Forge near Glasgow, Steel Manufacturer, 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 has for its object to provide an improved method of and apparatus
for hardening or tempering steel plates and other metal articles.
The chief feature of the said invention consists in the utilization for chilling or
cooling and hardening the articles to be treated of a medium which has been
reduced to a low temperature by artificial cooling means.
Another feature of the present invention consists in the treatment of metal in a
molten or semi-molten state in which cases except as hereinafter described the metal
is not brought into direct contact with the chilling medium.
A still further feature of our invention consists in applying pressure to the
article while undergoing treatment in accordance with our method of cooling.
In carrying our invention into effect we prefer to use for chilling the plate
or other article a liquid which as before indicated has been cooled to a low
temperature below that of melting ice by a freezing mixture or by chemical or
other suitable artificial cooling means, as for instance by carbonic acid, or ammonia,
which by its vapourization and consequent expansion will produce cold. The plate
or other article may after being heated to the proper temperature be conveniently
placed and suitably supported in a box or the like which box may be vertical,
horizontal, or inclined as desired, and through which the chilling liquid is passed.
By this treatment the article is rapidly chilled and hardened. In some instances
the liquid may not require to be circulated, the articles to be treated being in such
instances merely immersed therein.
In some instances we employ a solidified or partially solidified cooling medium,
the same being arranged as in the case of a liquid to make contact with the faces of
the plate or other article to be treated. Mixtures of snow or pulverized ice and
potash, or snow or pulverized ice and calcium chloride crystallized, or snow or
pulverized ice and dilute sulphuric acid, or anhydrous carbonic acid, form very
useful chilling media. Whether the chilling medium be liquid or solid, pressure
may or may not be applied thereto as may be desired during the chilling operation.
The chilling operation may be effected on metal in the molten or semi-molten
state in which case it is conducted in a jacketed mould through which the chilling
medium is circulated, or in a mould surrounded by pipes 'through which the chilling
medium is circulated, or which are filled with the chilling medium; or the mould
may be immersed in a vessel which contains the freezing or chilling medium, or in
other words may be surrounded by such chilling medium.
In some instances the plate to be chilled is separated from the chilling medium
by a thin plate so as to prevent actual contact therewith.
In the accompanying drawings,
Figure 1 is a transverse section, and
Figure 2 is a longitudinal section of a chilling box for carrying out this invention
as applied to the chilling of armour plates.

page_text: Figure 4 is an end view of the feed pipe connection.
Figure 5 is a plan partly in section, and
Figure 6 is a transverse sectional elevation of a special form of apparatus for
chilling circular objects.
Figure 7 is a longitudinal section, and
Figure 8 is a sectional plan of apparatus for chilling shell externally and
internally in accordance with this invention.
Figure 9 is a longitudinal section, and
Figure 10 is a sectional plan of apparatus for chilling projectiles externally and
under pressure.
Figure 11 illustrates a modification of Figure 9 wherein the point of the shot is
brought into actual contact with the cooling medium.
Figure 12 is a sectional elevation of another form of apparatus for chilling
armour plates, showing a thin partition between the plate and the chilling medium.
Like letters denote corresponding parts throughout the drawings.
Referring first to Figures 1 to 4, A is a box in which the plate B (for example)
see Figure 1 is placed for treatment. A is an opening in the top of the box
through which the plate can be inserted and removed. A2 is a hinged door for
closing said opening. A³ is a foot on which the plate rests. A³, A5 are internal
side ribs to support the plate laterally.
C, C are pipes arranged at the top and bottom of the box for introducing and
withdrawing the cooling medium. Said pipes are slit longitudinally or are
perforated whichever is preferred. D is a feed pipe for feeding the cooling
medium through the lower pipes C, C to the box, and D¹ is another pipe for
withdrawing the cooling medium from the box through the upper pipes C, C.
One such pipe D is preferably provided for each of the lower pipes C, and a pipe D¹
for each of the upper pipes C.
The plate after being heated to the desired temperature is introduced into the
box A, and the cooling medium is then circulated through the box thereby cooling
and chilling the plate, the length of time to which the plate will be subjected to
the cooling medium will of course depend on its thickness and on the degree of
hardness to be obtained.
Figures 5 and 6 show apparatus for chilling the tyres of railway vehicle wheels.
The cooling medium is not brought into direct contact with the cooling medium in
this instance but is circulated in an annular channel E formed partly in the base of
the apparatus, and partly in the cover F which is hinged at F to the base and can
be raised to admit of the insertion and removal of the wheels. F', F are clamps
for holding the cover firmly closed. The cooling medium enters through the
pipe D and passes out through the hinge of the cover which is made hollow for the
purpose.
Similar apparatus to this can be used for chilling crank pins and other circular
articles.
For chilling shell, we provide the apparatus shown in Figures 7 and 8.
G indicates a shell in position in a jacketed mould or receptacle H which is suitably
supported in a pit and is cooled by the cooling medium entering through the pipe Ď
and passing out through openings or ports H' at the upper end of the mould or
receptacle into an annular chamber H2 whence it flows away through the outflow
pipe D'.
The interior of the shell is chilled by direct contact of fluid entering by a
removable pipe J and passing out through the end of the shell and through
ports H into the annular chamber H2 aforesaid and thence away by the outflow
pipe D'.
The shell may be cast in the aforesaid mould or it may be cast in an ordinary
mould and then transferred to the above described receptacle to be chilled. The
shell may be chilled first externally and then internally or vice versa, or it may be
chilled outside and inside at the same time.

page_text: A modified construction of mould adapted for chilling projectiles is shown in
Figures 9 and 10. The jacketed chilling receptacle is formed by an outer casing H
and an inner strong removable part K which receives the projectile. The cooling
medium enters by the pipe D and passes away through the annular chamber H³ as
in the previously described arrangement. This chamber is in this instance made of
increasing width from the back thereof to the point opposite the outlet.
We have provided moreover for subjecting the projectile to pressure during the
chilling operation. Such pressure is supplied by a suitably operated ram L which
presses on a removable piston L' that fits the receptacle K and bears on the rear end
of the projectile.
Figure 11 shows a modification of this construction wherein the receptacle K is
pierced at its lower end to allow the point of the projectile to protrude therethrough
and come into actual contact with the cooling medium. By this means the point
may be made excessively hard while the remainder of the body of the projectile is
less hard. The wall of the receptacle K is also thinned near the point and shoulder
as shown to graduate the cooling effect.
The aforesaid apparatus for chilling projectiles and shells can by suitable
modifications be adapted for chilling rolls and other articles which may or may not
be cast in the chilling moulds. That is to say, it can be used for chilling metal
articles in a molten or semi-molten state.
For rolls it is preferable to cast them with a hollow core to admit of internal
hardening or chilling to any desired degree.
In each case the interior of the mould or that part which makes contact with the
projectile may be coated with carbon or other suitable carbonaceous substance.to
increase the hardening effect. This lining will be partially or entirely destroyed
by the molten metal, but will have sufficient durability to last until the molten
metal becomes set.
In Figure 12 an armour plate is shown undergoing treatment between upper and
lower boxes coutaining frigorific mixtures. The lower box A is supported on
suitable girders, and the upper box A is movable between girders M and is
connected to rods N, by which it can be raised and lowered. Each box is furnished
with a thin shield O of copper or other suitable metal that separates the frigorific
mixture from the armour plate to be chilled. These separating plates are not
however essential in all cases and are sometimes removed. Aº, A are drain pipes
for the lower box. For flat plates we prefer to chill both sides simultaneously to
prevent warping. A curved plate may be obtained by chilling the same more
severely on one side than on the other.
The temperatures at which we use the chilling media according to this inveution
are below that of melting ice.
Although we have only shown a method of applying pressure to projectiles and
the like while chilling the same, it is obvious that we can provide for applying
pressure to plates or other articles in a similar manner.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
1. A method of chilling or hardening steel plates and other metal articles by
means of a medium or of media artificially cooled to a temperature below that of
melting ice and brought into direct contact with the surface of the article to be
chilled.
2. The treating of metal in a molten or semi-molten state by artificially cooled
media, at a temperature below that of melting ice, substantially as, and for the
purpose, specified.
3. Subjecting the articles to pressure while chilling the face or faces thereof,
substantially as described.
4. The method of chilling hollow articles both internally and externally,
substantially as described.

page_text: 5. The method whereby the points of projectiles or like articles are made
excessively hard while the body is made less hard, substantially as described.
6. For chilling plates and other articles, apparatus constructed substantially as
described with reference to Figures 1 to 4, or to Figures 5 and 6 or to Figures 7
and 8, or to Figures 9 and 10, or to Figure 11 or to Figure 12.
Dated this 4th day of August 1894.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants..