IMPROVEMENTS IN THE TREATMENT OF INGOTS OF STEEL AND OTHER MALLEABLE METALS FOR THE REMOVAL OF IMPURITIES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Henry Clement Swinnerton Dyer at
the Office of the Commissioners of Patents on the 30th December 1882.
HENRY CLEMENT SWINNERTON DYER of Victoria Park, Manchester in the
County of Lancaster "IMPROVEMENTS IN THE TREATMENT OF INGOTS OF STEEL
AND OTHER MALLEABLE METALS FOR THE REMOVAL OF IMPURITIES
"
When metal is cast, the outside parts of the ingots being chilled by contact with
the mould set rapidly and then the cooling process continues more gradually until
the whole mass becomes solid. The part which remains longest liquid is in the
vertical axis about one third of the length of the ingot from the top.
It is a well known fact that alloying substances such as sulphur, phosphorus,
carbon, silicon or the like have a tendency to be withdrawn from those portions of the
mass which first solidify, and to collect in the more liquid part of the metal; this
process of driving out foreign substances from the metal as it becomes solid goes on
in obedience to natural laws and the consequence is that the cold ingot contains a
larger per centage of the alloying substances or impurities in and around the point
of final solidification than the other parts of the ingot. This causes more or less
marked irregularities in the mechanical and physical properties of the parts of the
ingot which are more or less removed from the point of final solidification, the
worst or most impure part of the ingot being in the centre about one third of the
height from the top, and it is of great importance to get rid of this part. If it is not
got rid of, plates rolled from the ingot will have lines of weakness, a serious defect
in boiler plates, and indeed, whatever be the purpose for which the ingot is used, it
is most desirable to get rid of this part. Even in the gold and silver used for
coinage these impurities are remarked to an extent to interfere with the purity
of the coins cut from the impure part of the plates from which the coins are
stamped.
Various methods have been employed to get rid of the objectionable parts of the
ingot, such as boring a hole through it, parting out the inside or cutting off about
a third from the top of the ingot. All these are costly operations and cannot be

page_text: done while the ingot is hot except the last named which nevertheless is somewhat
difficult with very large ingots.
I propose to treat the ingot as follows:
As soon as the ingot is in the best condition to be operated upon it is placed in
the most convenient manner to get power to bear upon it. A hollow die, the hole
in which is about the size of the part desired to be removed is either placed loose
on the top of the ingot or fastened to the ram of a hydraulic or other press while
the bottom of the ingot rests against an anvil;—pressure is then applied and as
the inside of the ingot is softer than the outside it will the more readily flow in
the line of least resistance which is up the hollow die The ingot is thus shortened
and the objectionable parts of the ingot which are thus forced up the hollow die
can either be removed at once by any convenient mechanical means or in the case
of large ingots can be used for holding them during the subsequent process of
forging. Still further to facilitate this operation a pointed or conical plunger may
first be forced into the centre of the head of the ingot which may have become
solidified by exposure thus as it were to tap into the still liquid or semi-liquid part
within.
This process can also be made available for removing the centre of the ingot
entirely should it be required for the manufacture of hoops, tires or the like. In
this case a plunger applied to the base of the ingot-the diameter of this plunger
corresponding with that of the hole, and the plunger being either fixed or movable
by hydraulic or other power. The plunger at the base of the ingot being forced
up will cause the semi fluid metal in the interior of the ingot to flow up the hole.
A similar plunger at the other end would in like manner remove the interior of
the ingot from the head, so leaving a hollow or tubular ingot consisting of the best
and soundest part of the metal.
Whether the whole or only a portion of the inside is to be removed, the ingot is
by preference placed in a strong mould box both to keep it symmetrical in form
and also to consolidate the metal as in forging.