Improvements in the Process of Annealing Steel.
Year: 1899

page_text: Date of Application, 5th Apr., 1899-Accepted, 2nd June, 1899
COMPLETE SPECIFICATION.
Improvements in the Process of Annealing Steel.
I, EDWIN DAVID WASSELL, of 720, Mellon Street, East End, Pittsburg, in the
State of Pennsylvania, United States of America, Artisan, 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:-
My invention relates to the art of metallurgy, has especial reference to open
hearth or Bessemer steel, has for its object a great reduction in the time required
to anneal such steel, and consists in a process of annealing heavy armor plate,
siege guns and other articles, as will be fully disclosed in the following specifi-
cation and claims.
In the accompanying drawings, which form part of this specification:--
Fig. 1 represents a vertical longitudinal section of a receptacle or box
employed in carrying out my invention and
Fig. 2 a verticle transverse section of a modified form of the same.
Reference being had to the drawings and the letters thereon, A indicates the
receptacle or box, having a cover B provided with depending flanges a which
extend the entire depth of the ends and sides of the box and rest upon a base b,
leaving a space between the flanges and the flanges e to be packed with clay,
should it be found desirable, or the flanges a may be made to extend down only
a short distance over the sides and ends of the box, as shown in Fig. 2.
CC are posts, movable on the bottom of the box to suit articles of different
dimensions, upon which the article to be treated rests, and for the purpose of
illustration D indicates a piece of armor plate in position in the annealing box.
The cover B is provided with pins or studs to be engaged by a crane or
derrick to remove and replace the cover.
.
The box is provided with axles e and wheels f, and travels upon rails g, to
be inserted and withdrawn from a suitable furnace.
The armour plate as it comes from the rolls reduced to the proper thickness
is taken directly to the annealing box and placed upon the posts CC and the
space around the plate is then filled with liquid oxide of iron, supplied from a
furnace used for liquifying the oxide.
After the box has been filled with liquid oxide of iron, the liquid is allowed
to cool sufficiently to become set or hard, but not below from 800° to 1200°,
and thereby form a crust and completely exclude the atmosphere; when the cover
is placed upon the box and the box with its contents moved into a suitable
furnace, where the temperature is maintained at from 800° to 1200° F., or more
if necessary, but not sufficient to decarbonize the metal, for about twenty four
hours, when the box is withdrawn from the furnace and allowed to slowly cool.
In the liquid oxide of iron I may use about 5% of lime for the protection of
the steel being annealed, as the mixture of the lime with the oxide will prevent
any of the impurities leaving the oxide of iron and being absorbed by the
steel.
I do not confine myself to any particular oxide, but include any oxide fusible
above 800° to 1200°, when used in liquid form in the manner herein described.

page_text: I desire to state further, that I do not confine myself to the idea of filling
the space around the plate with oxide of iron all at one time or pour off the
steel, but may, before the armor plate or other articles of steel are placed in
the annealing box, pour or run into the annealing box a given amount of the
liquid oxide to a depth of eight or nine inches, more or less, and allow it to
cool sufficient to support the plate to be annealed; in which case I dispense
with the posts C C.
I also desire to state that in the annealing of small or light steel castings it
will be necessary to pour the liquid oxide of iron into the annealing box so as to
form layers, each layer being sufficient to completely cover the casting or castings
to be annealed, thus forming tiers, allowing each layer of the liquid time to cool
and set before another layer is formed above it.
It may be proper to state for the benefit of those who may use my process of
annealing heavy castings or plates of steel, that if such castings or plates are
hot, say cherry red when the liquid oxide is poured into the annealing box and
around the plate or casting that the oxide will not adhere to the steel being
annealed, but the liquid oxide will remove all oxide from the plate or casting,
the surface of which after being annealed will be perfectly free from either oxide
or sand.
The annealing box may be used without the cap or cover, if the liquid oxide
is made deep enough above the upper surface of the armor plate or other article
of steel being annealed.
For complete and uniform annealing of the steel under this process, the steel
should be completely submerged or covered in the liquid oxide to a depth of
from six to ten inches.
Having now particularly described & ascertained the nature of my said inven-
tion & in what mauner the same is to be performed, I declare that what I
claim is:
(1)The process of annealing steel, which consists in covering the metal while
heated with a liquid oxide, allowing the oxide to partially cool and form an air
excluding crust, maintaining the heat in the metal and the oxide for a deter-
minate time, and finally removing the source of heat and allowing the metal
and the oxide to slowly cool.
(2) The process of annealing steel, which consists in covering the metal
while heated with a liquid oxide of iron, allowing the oxide to partially cool
and form an air excluding crust, maintaining the heat in the metal and the oxide
for a determinate time, and finally removing the source of heat and allowing the
metal and the oxide to slowly cool.
(3) The process of annealing steel, which consists in covering the metal
while heated with a liquid oxide and lime, allowing the oxide and the lime to
partially cool and form an air cluding crust, maintaining the heat in the
metal, the oxide and the lime for a determinate time, and finally removing the
source of heat and allowing the n.etal the oxide and the lime to slowly cool.
Dated this 4th day of April 1899.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.