Improvements in Carburizing Fluid Iron or Steel.
Year: 1891

page_text: Date of Application, 18th Aug., 1891
Complete Specification Left, 18th May, 1892-Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in Carburizing Fluid Iron or Steel.
JOHN EDWARD STEAD Analyst Middlesbro on Tees in the County of Yorkshire
England do hereby declare the nature of this invention to be as follows:-
My invention consists in adding solid carbon beneath the surface of molten iron
or steel which requires carbonising. The carbon is gradually absorbed & the metal
carbonised.
To effect this object I coat bars of iron or other strong support with carbon or
carbonaceous matter & force it into the fluid metal.
COMPLETE SPECIFICATION.
Improvements in Carburizing Fluid Iron or Steel.
I, JOHN EDWARD STEAD of Middlesbro-on-Tees in the County of York,
Analyst, 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 is an improvement on the method patented by John Henry Darby
in Patents Nos. 418 of 1888, 20586 of 1889, 4030 of 1890, 2673 of 1891 and
6303 of 1891 and relates more particularly to the method of adding carbon to
molten iron or steel in a basic converter, basic lined open hearth furnace, or its
equivalent, so as to prolong the basic process for the manufacture of steel whereby
the impurities are more completely eliminated.
By the present invention I force coke or other carbonaceous material beneath
the surface of the molten metal, where it is gradually absorbed and the metal
carburised.
There are various methods of forcing the carbonaceous material into the metal ;
the following is a description of the method I consider most suitable.
I cover one end of a bar of iron with firebrick tubes or sleeves and coat these
with coke or other carbonaceous material and plunge them into the liquid metal.
To coat the firebrick sleeves with the carbonaceous material, pulverized coke or
other form of carbon may be mixed with tar, molasses or other carbonaceous
material and pressed into a mould round the firebrick sleeves; the mass may then,
if desirable, be heated red hot out of contact with air so as to carbonize the binding
material and drive off moisture. If the carbon be still not sufficiently bound, it
may be again soaked with the liquid binding material and dried as before. Short
pieces of iron or steel wire may if required be mixed among the carbonaceous mass
to bind the same, or a coil of wire may be introduced into the mould, so as to
surround the sleeves at some distance from them and thus form a support for the
carbonaceous material. Silicate of soda or other mineral binding material may be
used instead of carbonaceous binding material.
Another method consists in packing the carbonaceous material into a hollow
iron or firebrick tube or sleeve forming the end of the bar or surrounding the end
of the bar, the carbon being between the two, drying the same if necessary, and
plunging the mass into the liquid metal.

page_text: 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
The improvement in the manufacture of iron and steel which consists in forcing
carbon beneath the surface of the molten metal where it is gradually absorbed and
the metal carburised substantially as and for the purpose described.
Dated this 17th day of May 1892.
WM. P. THOMPSON &.Co.,
Of Liverpool, Manchester, Nottingham, and London, Patent Agents.