IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON INGOTS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by Alexander Wilson at the Office of
the Commissioners of Patents on the 19th October 1880.
ALEXANDER WILSON, of Sheffield, in the County of York, Steel Manufacturer.
"IMPROVEMENTS IN THE MANUFACTURE OF STEEL AND IRON INGOTS."
The object of this Invention is to insure the gradual cooling and contraction of
steel and iron ingots of large size, and to prevent their "drawing" and “clinking”
when in the moulds.
It is well known amongst steel and iron ingot makers that ingots of large size
intended for forged guns, cranks, rolls, shafts, &c., are very liable to "draw" and
"clink" when cooling in the moulds, and sometimes after they have been removed
from the same, in consequence of the outside of the ingot cooling down and setting too
rapidly for the inner portion, which remains in a molten state for a long time after
the outsides and ends have set. The consequence is the outside cannot " contract
or "give" to the inside, therefore it draws the inner portion towards it, thus
forming a "cavity" or "clinking" it at or near the centre of the ingot.
"
To prevent this drawing or clinking of the ingots I employ a cast iron ingot
mould large enough for the purpose, or a sand mould which has been previously
rammed and formed in the interior of an ordinary moulding box, or in the sand
floor of a moulding shop, and line it with charred wood, pulverized charcoal,
graphite, asbestos, or other non-conducting material, which will not fuse when
subjected to the heat of the molten steel. By using a nonconducting material of
this nature I am able to use a lining of any required thickness, say, 3 or 4 inches,
according to circumstances. I then place the mould on a casting plate and cast the
ingot in the usual manner, and after making up the top of the mould with sand as
usual the ingot will be able to cool down so very slowly and gradually into such a
state as will allow of its being removed from the mould without fear of its " clinking,"
as is very often the case with large ingots cast by the ordinary method.
I propose to retain the lining in its position by having dovetailed recesses formed
vertically on the inner sides of the mould, and in some cases I insert a sheet iron
or sheet steel tube in front of the non-conducting material to keep it from falling
down into the mould, in other cases I may use a facing of graphite applied in a
plastic form for the same purpose.

page_text: When I use charred wood as a lining I take short planks of wood of the proper
thickness which have been previously charred in a "retort" or otherwise, and cut
them to the length and breadth required to fit the interior of the mould. I then
fasten strips of uncharred wood behind these now prepared sections in such a
manner that they will fit into the dovetailed recesses formed in the mould, and
when the mould is completely lined with these sections it will be ready for the
ingot to be cast within it. Any little unevenness on the face of the lining can be
made smooth (if necessary) by using a little plastic graphite.
When I use pulverized charcoal with a facing of plastic graphite I take a full
sized wooden model of the ingot required and plaster over its outer surface a coating
of plastic graphite, say, a half an inch in thickness. I then place the model in the
mould, and in the space (now formed equally between the coating on the model and
the interior of the mould) I put and slightly ram pulverized charcoal. After the
coating of graphite has set I withdraw the model from within the now formed
lining, when it will be found that it will retain its proper position, and when
perfectly dry it will be ready for the ingot to be cast within it.
To facilitate the withdrawal of the model I prefer to make it in parts or sections.
When I use a sheet steel or iron tube for a facing I make it the form of the
required ingot and place it inside the mould, and pack loosely graphite, pulverized
charcoal, or asbestos in the space formed between the exterior of the tube and the
interior of the mould.. It is then ready for the ingot to be cast within it.
When I use asbestos only as a lining I take the before mentioned model and
place it within and at an uniform distance from the sides of the mould. I then
put and firmly ram asbestos into the space formed between the outside of the model
and the inside of the mould, after which I withdraw the model, as before, when it
will be found that the lining will retain its position, and is now ready for the
casting of the ingot.
When a sand mould is used the various linings can be formed simultaneously
with the ramming of the surrounding sand, but with a cast iron mould the linings
are inserted as described above.