IMPROVEMENTS IN THE MANU- FACTURE AND TREATMENT OF STEEL
Year: 1884

page_text: I ROBERT HADFIELD of Sheffield in the County of York Steel Manufacturer
do hereby declare the nature of my invention for IMPROVEMENTS IN THE MANU-
FACTURE AND TREATMENT OF STEEL to be as follows :-
This Invention relates to improvements in the manufacture and treatment of
steel and has for its object the production of superior and best steels from English.
or other pig irons, or English or other scrap iron or steel scrap or steel-Hitherto it
has been the practice in the manufacture of high class steels to use costly and
expensive irons and to keep the silicon therein as low as possible, that is to say,
averaging about 10% (one tenth per cent) or less and to exclude it therefrom as
far as practicable.
•
Now my invention consists in adding to the materials under treatment whether
pig iron either wholly or to a great extent decarbonized, refined, or otherwise
treated, or scrap iron, or steel scrap, or both combined, or steel melted and produced
by any steel making process, silicon in the proportions of not less than 1% % up
to and including 5° keeping the carbon therein low-Such percentages of silicon
are obtained by means of silicon pig iron, and I use by preference a pig iron
containing 9% of silicon or thereabouts.
°
The steel obtained by my improved treatment may if requisite be hardened and
tempered in the usual manner. It is specially adapted for all kinds of steel toys
and tools whether with or without cutting edges, as such steel not only possesses
great hardness but is also much tougher than the steels ordinarily used for such
purposes and is also less liable to be burnt in the heating-By this invention a very
great economy is effected in the cost of production as compared with the cost
of the ordinary high class steels now produced and used-Firstly owing to its
dispensing with the necessity for employing as heretofore expensive foreign and
other high priced irons-Secondly-By its dispensing with the process known as the
"cementation" process-Thirdly-By its being applicable to any of the processes
used for the manufacture of steel.
1001

page_text: I ROBERT HADFIELD of 33 Southampton Buildings Holborn London do hereby
declare the nature of my invention for IMPROVEMENTS IN THE MANUFACTURE AND
TREATMENT OF STEEL 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 improvements in the manufacture and treatment of a
kind of steely iron which I call "silicon steel" and has for its object the
production of superior and best qualities of steel from English or other pig iron or
English or other scrap iron or steel scrap or steel containing little carbon.
Hitherto it has been the practice in the manufacture of high class steels to use
costly and expensive irons and to keep the silicon therein as low as possible that is
to say averaging about one tenth per cent or even less and indeed as far as
practicable to exclude it therefrom; as its presence has been thought and found to
be injurious whereas I have discovered that where silicon is allowed to act alone,
or is not affected materially by the presence of carbon it may either be retained or
added within limits to the materials treated and so be introduced as to improve the
quality of the iron or steely forms of iron under treatment.
My invention consists in adding silicon to the materials under treatment such as
pig iron which has been either wholly or to a great extent decarbonised refined or
otherwise treated-or scrap iron, or steel scrap or both combined, or steel having
little carbon and produced by any of the steel making processes now or heretofore
practised when such materials are fused or melted.
The silicon is added by me in the proportions of from 1% up to and including
about 5% of the quantity treated and the quantity of silicon added is varied
according to the quality of the product desired to be obtained and the purposes for
which it is required; as I have ascertained that the addition of silicon gives to the
material treated toughness and hardness according to the proportions added.
Where a product is required suitable for the manufacture of articles requiring
toughness, low per centages of silicon; say from about 1½ up to and including
per cent are employed.
Higher per centages of silicon up to and including about 5 per cent are employed
to give greater hardness to the product when required for the manufacture of articles
such as are usually made of hard steel.
The silicon is introduced with advantage into the materials with which it is to
be incorporated by mixing with them iron containing high per centages of silicon
say a pig iron containing nine percent of silicon or thereabouts commercially
known as "silicon pig iron."
The silicon steel made by my improved process which is based on the novel and
beneficial use of silicon as hereinbefore described may be used for tools and other
such purposes and when so used is hardened and tempered in the usual manner.
It is specially adapted for all kinds of steel toys and tools whether with or
without cutting edges as such steel not only possesses great hardness but is also
inuch tougher than the steels ordinarily used for such purposes and is also less
liable to be burnt in the heating and less liable to what is known as water
cracking.
By this invention a very great economy is effected in the cost of production of my
silicon steel as compared with the cost of the ordinary high class steels as now pro-
duced and used-Firstly-Owing to its dispensing with the necessity for employing
as heretofore expensive foreign and other high priced irons and Secondly-Owing to

page_text: the simple process of making this steel as employed by me and the dispensing with
the process known as the "cementation" process.
My invention is applicable to processes similar to those used for the manufacture
of steel,
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
1° The employment of silicon in the manufacture of silicon steel or iron having
the qualities of steel substantially in the manner and for the purposes herein before
specified.
2° The manufacture of various qualities of such silicon steel or steely iron
having the character of superior and best steels from English or other pig iron or
scrap iron or steel scrap or steel containing little carbon by the employment of
silicon substantially in the manner and in about the proportions specified.
Dated this 2nd day of February 1885.
SHIRLEY BOWDEN,
33, Southampton Buildings, Holborn, London,
Agent for the Applicant.