IMPROVEMENTS IN THE MANUFACTURE OF STEEL
Year: 1879

page_text: LETTERS PATENT to John Thomson King, of Liverpool, in the County of
Lancaster, Patent Agent, for the Invention of "IMPROVEMENTS IN THE
MANUFACTURE OF STEEL." A communication from abroad by Ogden Bolton,
of Canton, in the County of Stark, in the State of Ohio, one of the United
States of America.
Sealed the 12th September 1879, and dated the 25th March 1879.
COMPLETE SPECIFICATION filed by the said John Thomson King at the
Office of the Commissioners of Patents on the 25th March 1879.
JOHN THOMSON KING, of Liverpool, in the County of Lancaster, Patent
Agent. "IMPROVEMENTS IN THE MANUFACTURE OF STEEL." A communication
from abroad by Ogden Bolton, of Canton, in the County of Stark, in the State of
Ohio, one of the United States of America.
My Invention relates to a new method of manufacturing steel in what is com-
monly known as the "open hearth," that is to say, in a Siemens' or equivalent
furnace, and has for its principal object the production of high grades of steel suit-
able for tools, &c., for which the more expensive crucible steel is now necessarily
used.
The method heretofore adopted in making steel in the open hearth when using
iron blooms, iron sponge, steel, or scraps, is to start with a cast metal bath made
with either pig iron or spiegeleisen, to which the wrought iron blooms, scrap, &c.,
are added to decarburize, and finally, spiegeleisen or ferro manganese to recarburize,
but by said method it has heretofore been impossible to produce high grades of steel
or to compete with good English tool steel.
I will now proceed to describe my Invention so that others skilled in the art to
which it appertains may apply the same.
I first take carbon in any convenient form and charge the same into the furnace,
either a Siemens' or equivalent furnace, after which I place blooms, soft steel, or
sponge thereon and melt the same so that the molten metal shall run down through
the carbon and combine therewith. When the iron is all melted I sample it, and if
higher in carbon than required add such per centage of blooms or equivalent as will
reduce the carbon to, or very near to, the desired per cent. I then tap the steel into
a ladle or equivalent vessel and add thereto spiegeleisen or ferro manganese.
DQ077

page_text: In practice I have found the following quantities of carbon, iron, &c., to produce
good tool steel, and therefore recite the same, but do not expect or intend to be
limited thereto :-
I take three hundred and fifty (350) pounds of carbon and pack it in wooden
boxes, preferably about four feet long, one foot wide, and one foot deep; these
boxes so filled I charge into the furnace, placing them at the lowest or deepest part
of the furnace, and on top thereof I charge eleven thousand pounds (11,000) (one
half ton, more or less) of iron blooms. When the iron is all melted I take out a
sample and usually find the per centage of carbon to be about 1.50 °, and if the
per centage of carbon is higher than I desire I add more iron blooms to the bath
until a proper test shows the per centage of carbon in the bath to be 05 % higher
than I require in the finished steel. I then tap the steel into the ladle, and as the
steel is running out of the furnace I add about 1% of ferro manganese, allowing
the lumps (if not previously melted) to drop into the running stream of steel, thus
getting a thorough mixture.
It is not absolutely necessary to add the per cent. of ferro manganese specified, as
I find that I can run the steel made by the desired process with but a trace of ferro
manganese, or practically none at all, and the less ferro manganese is used the finer
will be the steel.
In lieu of packing the carbon in boxes or canisters it may be compressed or other-
wise formed into a solid mass, or in some cases (though not by preference) it may
be charged loosely or in powdered form.
Steel made as specified will be found equal to good English tool steel, and has
been used successfully in the manufacture of nailers' knives, lathe tools, black-
smiths' tools, oil well tools, and taps and dies.
For the commoner grades of steel cheap blooms can be used, and in making lower
carbon steel so much carbon will not be required to commence with, as 1.5% carbon
at the start will give about 1% in the steel. In some instances I may first charge
a layer of blooms, then a layer or carbon, and then again a layer of blooms.
Having thus described my Invention, what I claim and desire to secure by
Letters Patent is,―
1st. The method herein described for the manufacture of steel by the open hearth
process, the same consisting in first charging the carbon on the bottom of the open
hearth and charging the blooms, iron sponge, or soft steel, or any part of them on
top of the carbonaceous matter previous to fusion, substantially as and for the
purpose specified.
2nd. In the manufacture of steel by the open hearth process, first charging the
carbon solidified or packed in boxes or canisters on the bottom of the open hearth,
and charging the blooms, iron sponge, or soft steel thereon previous to fusion, sub-
stantially as and for the purpose specified.
3rd. In the manufacture of steel by the open hearth' process, first charging the
carbon on the bottom of the furnace or open hearth; secondly, charging the blooms,
iron sponge, or soft steel, then melting the mass, and finally adding ferro manganese
or spiegeleisen after or at the time the molten metal is tapped from the furnace,
substantially as and for the purpose specified.
In witness whereof, I, the said John Thomson King, have hereunto set my
hand and seal, this Twenty first day of March, in the year of our Lord
One thousand eight hundred and seventy-nine.