Year: 1887

page_text: Date of Application, 30th June, 1887
Complete Left, 29th Mar., 1888
Complete Accepted, 4th May, 1888
1, ROBERT ABBOTT HADFIELD of Sheffield in the County of York Steel Manufacturer,
do hereby declare the nature of this invention to be as follows:-
This Invention has for its object to effect a considerable economy in the manufacture
of self-hardening and other steels which are at present made from expensive foreign
irons to which wolfram ores or other similar mixtures are added.
"
This 1 effect by substituting for such expensive foreign irons common iron either
wholly or to a great extent decarbonised such for instanco as the iron which is com-
mercially known as cut iron" and employing alloys of carbon, silicon, tungsten,
manganese and sometimes chromium in conjunction therewith. The proportions in
which I use any or all of such alloys vary according to the nature of the materials
treated and the steel required to be produced (that is to say) Carbon may be present
in proportions varying from about per cent to about 24 per cent-Silicon from
about per cent to about 4 per cent-Tungsten from about per cent to about 12 per
cent Manganese from about per cent to about 25 per cent and Chromium when
required from about per cent to about 12 per cent.
Such alloys may either be added separately or otherwise and either in a molten or
solid state to the iron forming the base of my improved steel.
Ordinarily I prefer to entirely decarbonise the iron previous to adding such alloys
thereto but it may sometimes be found advantageous to arrest decarbonisation at an
earlier stage. My invention is applicable to the Bessemer, Siemens-Martin Ponsard,
Thomas Gilchrist or other processes for manufacturing steel.
ELT & Co.,
33, Southampton Buildings,
Holborn, London,
Agents for the Applicant.

page_text: CUM LEIE DIMUITICATION.
Improvements in the Manufacture of Steel.
I ROBERT ABBOTT HADFIELD of Sheffield in the County of York, Steel 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 :-
This Invention has for its object to considerably reduce the cost of manufacture of
self hardening and other steels which are made at present from Swedish and other
expensive bar irons alloyed with wolfram ores or other similar mixtures.
My invention is applicable to the Bessemer Siemens-Martin Ponsard Thomas
Gilchrist and other processes which enable decarbonised iron which forms the base of
my improved steel to be produced very cheaply. When the crucible process is used
I employ preferably as such base what is known commercially as
"cut iron " which is
about one third of the price of the commonest qualities of Swedish irons.
To carry out my invention. I take either decarbonised iron or cut iron and treat it
with the following alloys viz-carbon-silicon-tungsten and manganeso and some-
times chromium when required, (that is to say) when the resultant product is to be a
steel possessing special powers of resistance to compression strains; the effect of the
addition of chromium being to enable the steel to sustain much greater compression
than it would otherwise be capable of bearing. The exact proportions in which such
alloys are employed vary according to the materials treated and the degree of hardness
required in the steel to be produced as the greater the hardness the higher the
per centages used consistent with its being possible to forge or roll the resulting
product.
The following table of per centages however indicates the limits between which such
proportions may be varied and will afford sufficient direction to those skilled
in the art of manufacturing steel to onable them to carry out my invention that is
to say
Carbon from about per cent to about 2 per cent.
Silicon from about per cent to about 4 per cent.
Tungsten from about
per cent to about 12
per cent.
Manganese from about per cent to about 25 per cent.
Chromium (when employed) from about per cent to 8 per cent.
"
I prefer to add each of the alloys separately thus for instance the carbon may be
added by means of what is commercially known as "refined white iron
or any other
suitable carbon alloy.-The silicon by means of "ferro silicon"
or any other suitable
silicon alloy The tungsten by means of "ferro tungsten" or any other suitable alloy
of tungsten-The manganese by means of "ferro-manganese ог "spiegel" or any
other suitable alloy-The chromium by means of "ferro chromium"
suitable chromium alloy.
33
or any other

page_text: It is however obvious that such alloys may be added in many different ways for
instance the Carbon and manganese may be added together in one alloy such as "low
spiegel" but when added separately as previously mentioned greater certainty is
ensured with respect to the per centages employed and more perfect results are
thus obtained than when compound alloys aro used which are much more liable
to vary.
The alloys may be added either in a molten or solid state but preferably I add them
in a molten condition so as to facilitate their thoroughly mixing with the iron under
treatment and forming a perfectly homogeneous mass.
I would here observe that I entirely dispense with the use of wolfram ores to obtain
the desired per centage of tungsten in the steel as such ores are extremely unreliable
and give uncertain results. Charcoal however may be added in any suitable propor-
tions to obtain the desired per centage of carbon.
When making self hardening steel I add the tungsten thereto in such quantities as
to produce therein a per centage of not loss than 6 per cent. When the crucible
process is used the alloys to be added to the cut iron may either be charged along
therewith or at any subsequent stage of the melting process.
When the Bessemer Siemens or other processes are employed I add the alloys as
soon as the iron under treatment is sufficiently decarbonised. Stoel made according
to my invention may be run into ingots or other forms and may then be forged or
rolled into bars or other shapes.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. In the manufacture of steel the employment of common iron such as decarbonised
iron or cut iron in combination with alloys of carbon-silicon-tungsten and
manganese and also when required of Chromium all respectively used substantially in
the proportions and manner and for the purposes hereinbefore described.
2. The improved process for the manufacture of self-hardening and other steels
hereinbefore described.