Improvements in and relating to a New and Useful Process for Treating Crude or Low Grade Steel to Produce a Refined or High Grade Steel.
Year: 1889

page_text: Date of Application, 5th Feb., 1889
Specification Accepted, 9th Mar., 1889
COMPLETE SPECIFICATION.
Improvements in and relating to a New and Useful Process for
Treating Crude or Low Grade Steel to Produce a Refined or
High Grade Steel.
We, HENRY MARTIN REDEMANN, residing at No. 259, East Market Street, in
the City of Louisville, County of Jefferson and State of Kentucky, United States
of America, Cutler, and ROBERT JOHNSON TILFORD, residing at No. 125, East
Main Street, in the above named City, County, State and Country, Merchant, do
hereby declare the nature of this invention and in what manner the same is to be
perforined, to be particularly described and ascertained in and by the following
statement :-
Our invention relates to certain new and useful improvements in the treatment of
crude or low grade steel to produce a refined or high grade steel.
The most successful method of producing low grade steel is that known as the
Bessemer process described in his Patent of 1855, but this product as is well known
is suitable chiefly for railways, axles, and like uses, and is totally unsuited for
structures, machinery and tool purposes, unless repuddled, hammered and rolled, for
the reason that in its normal state it is too soft, and when hardened it becomes too
bard and brittle for the purposes stated.
It was the recognition of these inherent defects in the Bessemer and low and
medium grades steel which led us to the investigation of the subject which has
developed our present invention, the object of which is the production at slight cost
and a minimum degree of labor, of a higher grade and more refined steel by
treating the Bessemer and other low and medium grades steel in such manner as to
produce a molecular change from a coarse grain to a fine grain, and silky fracture,
to increase the tensile strength, elasticity, toughness and ductility, and to greatly
increase the carbon. We have found from experience that uniform results in all
instances flow from the treatment of metals having like properties.
With these ends in view our invention consists:
In heating low grade steel to a degree of heat represented by white heat, and

page_text: Sulphate of Alumina and Ammonia one and a half (14) onnces.
Glycerine, three (3) ounces.
Water, one half (}) gallon.
As further explanatory however of the advantages gained by the present invention
we would state that by the practice of our process (which should be understood as
being distinguished from the processes for tempering steel in oil) the nature, the
physical construction, and the molecular construction of the metal is completely
changed; whereas, the tempering of steel in oil as practised by some processes,
simply tempers the steel more slowly than is done by tempering in water and other
properties, leaving the metal less hard, but somewhat tougher than water-tempered
material. The changes caused by the oil-tempering process are merely temporary,
and do not change the physical or granular construction of the metal, and such
changes as are caused thereby can be readily neutralized by re-heating and allowing
the metal to cool. The changes caused by treatment by our process are permanent,
and cannot be removed by any known treatment or process without entirely destroying
the steel properties of the metal by burning.
We have of course been unable to analyze the gases resulting from the contact of
the hot metal hody with the bath; but are led to believe that they constitute a hydro-
carbon gas, which has a strong affinity for the metal, and that the latior being in a
heated state is in such a physical condition as to readily take up or absorb such gas,
but as to the fact that the metal is highly improved wo have no doubt whatever, us
has been demonstrated by all the well known scientific and mechanical tests.
It will be understood of course, that when the treatment is applied adjacent to the
furnaces where the low grade steel is manufactured, the ingots may be treated without
re-heating, and thus the expense of such re-heating is avoided. After the metal has
been subjected to the treatment it is allowed to cool in the ordinary manner and it
may afterwards be subjected to any ordinary hardening or tempering process, and the
tomper may, if necessary, be drawn and again restored, without at all affecting the
other properties acquired from the bath.
We are of course aware that the quality of Bessemer and other low and medium
grades steel may be improved by what is known as the dry or comentation process,
Tut this requires a large expenditure of skilled labor and great length of time, and
that too without always securing uniform and satisfactory results

page_text: We desire it to be distinctly understood that we lay no claim to the broad idea of
increasing the quality of steel by subsequent treatment, as that has been heretofore
done, especially by what is known as the cementation process which may be termed a
dry process, our invention differing from such process in the particular that it requires
a period of time amounting to a small percentage of the time required in the
cementation or dry process, and is in contra-distinction to such process, essentially a
liquid or wet process. The former requiring many days, while the latter involves
only a few minutes.
By our invention we greatly increase the tensile strength, and elasticity, and yet
do not destroy the per cent. of reduction or ductility. Whilst with ordinary tempering
the tensile strength and elasticity are greatly increased, but the per cent. of reduction
and ductility are very much impaired.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
The process of converting low grade steel into refined or high grade steel which
consists in first heating the metal to be treated, to a degree of heat represented by
white heat, and then subjecting the metal so hoated to a previously prepared liquid
bath, which by contact with the heated metal gives out hydro-carbon gases which are
taken up by the heated metal, and allowing the metal to remain in such bath till
practically cooled, substantially as herein before set forth.
MAAL 1
HENRY MARTIN REDEMANN.
ROBERT JOHNSON TILFORD.
By Jensen & Son,
77, Chancery Lane, London, W.C.,
Patent Agents.