Improvements relating to the Manufacture of Steel.
Year: 1890

page_text: Date of Application, 29th July, 1890
Complete Specification Left, 18th Apr.. 1891-Accepted, 25th July, 1891
PROVISIONAL SPECIFICATION.
[Communicated from abroad by LA SOCIÉTÉ VANZETTI SAGRAMOSO & Co., of
Milan, in the Kingdom of Italy.]
Improvements relating to the Manufacture of Steel.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention to be as follows:-
-
This invention relates to the manufacture of steel presenting a high degree of
hardness.
Extra hard steel for tools, projectiles and the like has heretofore been manu-
factured in crucible furnaces. It owes its properties exclusively to the carbon and
the various metallic compounds of iron which have been incorporated and form an
alloy therewith.
In general hard steel may be defined as an alloy of iron, carbon and such metals
as chrome, wolfram, copper manganese, and the like.
Its characteristic properties are obtained by combining the several ingredients in
predetermined proportions and by eliminating as completely as possible the other
substances such as silicon, manganese, and the like, the latter remaining in the
metal in definite proportions. Taking as a typical example the manufacture of
chrome-steel which is most generally employed it may be said that the attempts
hitherto made to obtain this metal in great quantities in the converter or upon the
sole have not given satisfactory results.
The state of oxidation of the Bessemer and Martin baths is a hindrance to the
total incorporation of the chrome added in the form of an alloy of ferro-chrome.
Chrome is a very oxidizable body, and the oxide of the same does not combine
with the scoria, either as a base or as an acid.
Accordingly the oxide will not be incorporated with the metal intermolecularly
as it were, and will render it hot short, very heterogeneous and cold-short.
The method which forms the subject of the aforesaid invention, and which is
applicable to steel produced either in great or small quantities, consists in preparing
the bath in such a manner that with a minimum of disoxidizing foreign elements
the carbon and the metals necessary for the hardening shall be added exactly in
predetermined quantities.
Converter or Martin-furnace steel being obtained at the desired degree of
decarburization, the bath is disoxidized by a sufficient quantity of silico-spiegel
whereby is introduced a minimum quantity of silicon and manganese with traces of
carbon, manganese and silicon passing into the scoria.
Then a predetermined quantity of aluminium in the form of rich alloys is
added.
The aluminium can be used alone as a disoxidizing agent. In any case the two
alloys may be employed either separately, that is to say successively or simul-
taneously for preparing the bath before the addition of ferro-chrome the proportion
of which can be varied with the degree of hardness which is to be obtained.
Dated this 29th day of July 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Steel.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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:-
This invention relates to the manufacture of steel having a high degree of
hardness.
Extra hard steel for tools, projectiles and the like has heretofore been manu-
factured in crucible furnaces. It owes its properties exclusively to the carbon and
the various metallic compounds different from iron which have been incorporated
and form an alloy therewith.
In general hard steel may be defined as an alloy of iron, carbon, and such metals
as chrome, wolfram, copper manganese, and the like.
Its characteristic properties are obtained by combining the several ingredients in
predetermined proportions and by eliminating as completely as possible the other
substances, such as silicon, manganese, and the like, the latter remaining in the
metal in definite proportions. Taking as a typical example the manufacture of
chrome-steel which is most generally employed it may be said that the attempts
hitherto made to obtain this metal in great quantities in the converter or upon the
sole have not given satisfactory results.
The oxidation of the Bessemer and Martin baths hinders the total incorporation
of the chrome added in the form of an alloy of ferro-chrome. Chrome is a very
oxidizable body, and the oxide of the same does not combine with the scoria, either
as a base or as an acid.
Accordingly the oxide will be incorporated with the metal intermolecularly as it
were and will render it hot-short, very heterogeneous and cold-short.
The method which forms the subject of the aforesaid invention, and which is
applicable to steel produced either in large or small quantities, consists in preparing
the bath in such a manner that with a minimum of deoxidizing foreign elements the
carbon and the metals necessary for the hardening shall be added exactly in
predetermined quantities.
Converter or Martin-furnace steel being obtained at the desired degree of
decarburization, the bath is deoxidized by a sufficient quantity (2% to 3%) of
silico-spiegel whereby is introduced a minimum quantity of silicon and manganese
with traces of carbon, manganese and silicon passing into the scoria.
A predetermined quantity (0·05% to 0.15%) of aluminium in the form of rich
alloys is then added."
The aluminium can be used alone as a deoxidizing agent. In any case the two
alloys may be employed either separately that is to say successively or simul-
taneously for preparing the bath before the addition of ferro-chrome the proportion
of which can be varied with the degree of bardness which is to be obtained.
The proportions being the same as those which have been already employed in
the well known method of making chrome steel in crucibles, other additional metals
may be employed in lieu of ferro chrome, such as wolffram, copper, manganese and
the like, these additions being always made in the same proportions as those
usually employed for obtaining steel containing the last mentioned metals.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is: :-
The application of silico-spiegel and ferro-aluminium employed simultaneously or
separately, that is to say one after the other, as deoxidizing agents, introducing

page_text: only traces of foreign substances into the bath, in order to obtain a bath adapted to
combine with other additional metals such as chrome, wolfram, copper manganese
and the like, and with carbon, and thus produce alloys in definite proportions like
the purest and best cement steel cast in crucibles.
Dated this 18th day of April 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.