Improvement in the Treatment of Steel.
Year: 1891

page_text: Date of Application, 17th Mar., 1891-Accepted, 25th July, 1891
COMPLETE SPECIFICATION.
Improvement in the Treatment of Steel.
I, WILLIAM BULLUS MIDDLETON, a Citizen of the United States, residing
at Lancaster, Lancaster County Pennsylvania, United States of America,
Manufacturer, 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 :-
I have discovered that by heating Bessemer or other well known kinds of steel
with silica, silicate of soda, or other silicate, an effect is produced upon the steel so
treated and impregnated with silica or silicate, which is remarkable in that the
steel is not only prevented from being deteriorated in quality in the heating
operation, but is also greatly improved for the purposes for which steel is ordinarily
employed.
My invention is based upon the foregoing discovery and consists in impregnating
manufactured steel with silica, silicate of soda, or other silicate, by heating it
to such a degree as to cause it to absorb silica or a silicate.
My invention may conveniently be practised, either, by coating or covering the
steel to be treated, prior to the heating operation, with silica, silicate of soda, or
other silicate, either in the form of a solution, or in a dry condition; or, by treating
the steel with, or adding to it during the heating operation, silica, or a silicate, and
then heating the steel to such a temperature as to cause it to absorb the silica or
silicate.
My invention provides a method by which steel may be heated and afterwards,
if desired, worked, and although the invention is not necessarily restricted to the
treatment of scrap or waste steel, yet it may, with great advantage, be employed in
converting scrap or waste steel into a form or forms fit to be utilized for purposes
for which scrap or waste steel would otherwise be useless.
In the practice of my invention I prefer to use a solution of soda or other
silicate, or a solution of silica in an alkali, and to coat the piece or pieces of steel to
be treated therewith, prior to the heating operation, and thereafter, to subject
said steel to pressure or treatment between rolls, or under the hammer.
The solution of silica or silicate of soda, may, with advantage, be a strong or
saturated solution, and it may conveniently be applied to the steel to be treated
by dipping the steel into the solution, or by pouring the solution upon the steel.
In the practice of my invention I have found that a temperature sufficiently high
to enable me to work the steel between rolls or under the hammer is sufficient to
cause the proper impregnation of the steel with the silica or silicate to produce the
result desired.
I do not confine myself to the use of a solution of silica in an alkali, or of
a silicate of soda, or of a silicate of any other material, as silica, or silicate, in a
dry condition, may, without departure from my invention, be used, and either of
these materials may be applied to the surface of the steel before the heating
operation, or be applied or added to the steel during the process of heating it.
In the practice of my invention, I prefer, as already stated, to employ a solution
of silica in an alkali, or of a silicate, to coat the piece or pieces of steel to be treated
before the heating operation, for the reason that such practice is convenient and
economical, and for the further reason that the product obtained is, perhaps, more
homogeneous than that obtained by other methods of practising the invention. The
silicate of soda which by preference I employ, contains no more soda than is
absolutely necessary for the formation of the silicate.
It has been found in practice that the mere coating of the steel to be treated

page_text: with silica or with a silicate by spreading it upon its surface or dipping the steel
into a bath of silicate will produce the desired result.
As a result of the treatment of steel in accordance with my method, the quality of
the steel is greatly improved: for example, low grades of Bessemer steel, as well as
low grade steels of other varieties, which, before treatment, are utterly unfit to
make a cutting tool from, can, after being subjected to the treatment hereinbefore
described, be utilized for the manufacture of high class cutting tools, such, for
instance, as knife or razor blades ;-and repeated experiments in the practice of my.
method have demonstrated the fact that treatment by impregnation with silica or a
silicate greatly improves the constitution of the entire mass of the steel.
I am unable to state the rationale of the effects which are by the practice of my
invention produced on the constitution of the steel, and at this time can only say
that I know that the described treatment produces a new result which, in my
opinion, is caused by the metal becoming impregnated with the silica or silicate
employed. I, therefore, in this Specification employ the word "impregnate " as the
best term known to me to express my idea concerning the result produced.
Having now particularly described and ascertained the nature of my said inven
tion and in what manner the game is to be performed, I declare that what I
claim is :-
The process of improving the quality of steel, which consists in heating it in the
presence of and impregnating it with silica or a silicate, as specified.
Dated this Twenty-fourth day of January A.D. 1891,
WILLIAM BULLUS MIDDLETON: