IMPROVEMENTS IN THE MANUFACTURE OR TREATMENT OF IRON AND STEEL ass
Year: 1885

page_text: I JOSE LLETGET Y SARDA of Barcelona in the Kingdom of Spain but at present
of 188 and 189 Gresham House Old Broad Street in the City of London Chemist
do hereby declare the nature of my said Invention for "IMPROVEMENTS IN THE
MANUFACTURE OR TREATMENT OF IRON AND STEEL to be as follows:-
"
The principal object of my Invention is to effect the purifying refining hardening
or tempering of steel so as to convert steel of a comparative low quality to steel of
a higher quality but it is also applicable to the treatment of iron.
According to my Invention I heat the metal to be treated until it attains a high
red heat and then I plunge the metal when at this heat into a bath of water and
sulphuric hydrochloric or nitric acid and potash, soda or manganese salt. After
the metal has lost its red colour I add to the bath sulphuric ether or ammoniacal
salt or the equivalent thereof I then withdraw the metal and reheat it and hammer
or roll it into the required form or otherwise treat it in the ordinary way and then
immerse it in water until it is cool.
J. HENRY JOHNSON,
47, Lincoln's Inn Fields, London, W.C.,
Agent for the said Josè Lletget y Sardà.

page_text: COMPLETE SPECIFICATION.
I, JOSE LLETGET Y SARDA of Barcelona in the Kingdom of Spain but at present
at 188 and 189 Gresham House, Old Broad Street in the City of London, Chemist
do hereby declare the nature of my invention for IMPROVEMENTS IN THE MANU-
FACTURE OR TREATMENT OF IRON AND STEEL and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement :-
The principal object of my invention is to effect the purifying refining hardening
or tempering of steel so as to convert steel of a comparative low quality into
steel of a higher quality but it is also applicable to the treatment of iron.
According to my invention I take the metal to be treated in the form of ingots
pigs or bars and I heat it until it attains a high temperature and then I plunge
the metal when in this heated state into a bath composed of water and nitric acid
and soda using by preference Carbonate of Soda the ingredients being employed in
the proportions hereinafter stated or thereabouts. The temperature to which the
metal should be heated will vary in accordance with the size of the mass or pieces
to be treated for example a mass say a foot square should be heated to a white
heat whilst a strip say an inch thick should be heated to a high red heat My
improved process of treatment is applicable to iron and steel in large masses and
does not require the metal operated upon to be disintegrated or granulated; it is in
fact efficient when applied to iron or steel in large or small masses.
After the temperature of the metal has been lowered to the extent of losing its
white or red color I find it advantageous in some cases to equalize the temperature
of the bath by adding thereto sulphuric Ether or Ammoniacal salt or the equivalent
thereof but I prefer to use a water jacketted bath, the current of water through
the jacket equalizing the temperature of the bath.
And in order that my Invention may be properly understood I will more
particularly describe the manner in which the same may be carried into effect.
The metal that is to be treated is heated in a furnace or converted to a degree
of heat varying with the size of the mass or particles treated as was hereinbefore
mentioned. The heated metal is quickly introduced into a bath of the hereinbefore
mentioned ingredients contained in a receptacle of clay brick or the like with walls
or sides say about 1/2 inches thick. In operating on a large scale these walls
or sides should be surrounded externally by a casing or jacket through which
passes a current of cold water in order to prevent them from becoming overheated
and to maintain a uniform temperature in the bath contained in the receptacle.
I have ascertained that by increasing or diminishing the proportion of soda used
in forming the bath a steel of more or less hardness will be produced.
The following average example may be given to serve as a rule for making the
bath for operating with good effect but the differences of the composition and
structure of iron and steel will as will be well understood by persons acquainted
with the manufacture of iron or steel render it necessary to somewhat vary the
proportions of the ingredients that should be used for composing the bath so as to

page_text: suit the kind of metal to be treated and to produce the quality of iron or steel
required.
The quantity of water employed for the bath should be about 6 litres (say
10 pints) for a kilogramme (2·205 lbs avoirdupois) weight of metal to be treated
for example for tempering an ingot, sheet bar or the like weighing one kilogramme
(2.205 lbs avoirdupois) at least 6 litres (say 10 pints) of water are required. The
nitric acid should be used in the proportion of one part of acid to 12 parts of water
as a minimum and 2 parts acid to 12 parts of water as a maximum.
The
proportion of the carbonate of soda to acid should be from 1 to 4 of acid as a
minimum and equal parts as a maximum it being borne in mind as above stated
that by diminishing the proportion of soda to the acid the steel produced is made
less hard or more mild.
The metal should remain in the bath until cool and be suspended and moved
therein in order to enable the bath to act effectually upon the metal. The metal
is then removed and treated in any desired or ordinary way by the processes of
remelting or rebeating and rolling or the like.
By the treatment herein before described the purification refining and hardening
and consequently the general improvement of the metal may be conveniently,
economically, and successfully effected. I find that a bath composed of nitric acid
and water and carbonate of soda in about the proportions indicated will give the
best results but it is obvious to Chemists that in some cases for the purpose of
effecting the object as above stated my process may be somewhat varied by using
agents known to act chemically in an equivalent manner to those which I prefer
to use that is to say, other acids or combinations of acids may be used in place of
the nitric acids and other soda salts may be used in the place of the Carbonate of
soda and produce more or less similar results but not so efficiently.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1st The improved method or process of treating iron or steel by immersing it
when heated in a bath of Nitric acid and soda, or their equivalents, combined with
water in about the proportions hereinbefore defined, and substantially in the
manner hereinbefore set forth.
2nd The manufacture of iron or steel by the improved process hereinbefore
described.