Improvements in the Manufacture of Steel.
Year: 1893

page_text: Date of Application, 16th Dec., 1893
Complete Specification Left, 14th Sept., 1894-Accented, 20th Oct., 1894
PROVISIONAL STEIFICATION.
Improvements in the Manufacture of Steel.
I, CARL JOHAN LAURENTZ LEFFLER, of Havelock Street in the City of
Sheffield, Metal Agent, do hereby declare the nature of my invention to be as
follows
The object of my invention is to improve the hardness and strength of steel by
the introduction of boron therein, in such proportions as will produce a steel most
suitable for the purpose, for which it is intended to be used.
As boron itself cannot be directly taken up by or combined with steel, I use a
previously prepared boron iron, which may be introduced at various stages of the
operation of melting, in the crucible or the open hearth furnace, but may be most
advantageously introduced at an interval before the steel is ready to be teemed,
sufficiently long to allow the boron iron to become uniformly distributed throughout
or combined with the mass of the steel.
When the steel is being made in the Bessemer furnace it is necessary to introduce
the boron iron into the ladle in which the steel is run for teeming into moulds or
other receptacle, and it may also be introduced in this manner when the steel is
made in the open hearth furnace.
Boron may thus be introduced in steel or ingot metal of all tempers, from mild
steel, so called, to the hardest steel used, impure carbon steels, or in steels alloyed
with other metals, as for instance with tungsten, chrome, nickel, molybdenum,
cobalt and the like, either singly or in combination, and such boron steels may be
used for all purposes for which the said steels are used, such as for example, for
welding steels, for cutting tools of all kinds, for dies, wire, guns, projectiles, armour
plates, forgings and castings.
Dated the 15th der of Dearmboy 1002
I, CARL JOHAN LAURENTZ LEFFLER of Havelock Street, in the City of
Sheffield Metal Agent 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 :-
The object of my invention is to increase the hardness and strength of steel by
the introduction of boron in such proportion as will produce a steel suitable for the
purpose for which it is intended to be used.
In carrying out my invention, I use a previously prepared boron iron which may
be introduced at various stages of the operation of melting in the crucible or the
open-hearth furnace, but may be most advantageously introduced at an interval
before the steel is ready to be teemed, sufficiently long to allow the boron iron to
become uniformly distributed throughout or combined with the mass of steel; or
it may be introduced in the ladle into which the steel is run from an open-hearth
or a Bessemer furnace.

page_text: Boron may thus be introduced in steel of all tempers, from mild steel so called
to the hardest steel used, in pure carbon steels, or in steels alloyed with other metals,
as for example, with tungsten, chrome, nickel, molybdenum, cobalt and the like
either singly or in combination, and such boron steels may be used for the various
purposes for which the said steels are generally used.
From ferro boron (boron iron) produced by the method as described in my
Patent No. 24230, 1893, and containing 20% boron I have made steel
containing % to 1% boron, which has proved superior to steel made in the same
way but without any boron. To what extent the boron may be further increased
will not only depend upon how any such increase will improve the steel for a given
purpose, but also how the ingots will work or draw into finished steel; from its
powerful influence however it does not appear likely that more than 1% can be
advantageously introduced.
The proportion of ferro boron required to introduce a given percentage of boron
into the steel, will depend upon the percentage of boron in the ferro boron, and
must be calculated accordingly.
.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In the manufacture of steel, the introduction of boron, in the form of boron iron,
for the purpose specified, and as herein before described.
Dated the 11th day of September 1894.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.