Improvements in Methods of Partially Decarbonizing and Converting Iron.
Year: 1894

page_text: Date of Application, 14th June, 1894
Complete Specification Left, 14th Mar., 1895-Accepted, 4th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Methods of Partially Decarbonizing and Converting
Iron.
We, SAMUEL HUPTY, of 46, North Third Street, in the City of Camden,
State of New Jersey, United States of America, Accountant, and JOSEPH KAY
CALDWELL, of 37, West Tulpehocken Street, in the City of Philadelphia, State
of Pennsylvania, United States of America, Mechanical Engineer, do hereby
declare the nature of this invention to be as follows:-
One object of our invention is to remove a certain percentage of curbon from
solid forms of cast iron in which the carbon is present in such proportion as to
render the metal hard and brittle, the result of this part of our invention being to
convert the cast iron into steel of such ductility that it can be shaped, hammered,
drawn or rolled, or can be tempered in order to form cutting tools or for other
purposes for which tempering is usually employed, this part of our invention
being of special value in treating articles cast in the form in which they are to
be used.
The main feature of our invention consists in subjecting the metal, while highly
heated but still considerably below the point of fusion, and therefore retaining its
solid form, to the action of the gases resulting from the decomposition, by heat, of
a liquid or liquids composed of or containing nitrogen, hydrogen and oxygen.
The liquids employed may be either acid or alkaline, an instance of an acid
liquid available for the purpose is nitric acid (HNO,), an instance of an alkaline
liquid is ammonium hydroxide (NH, OH) the ordinary aqua ammonia of commerce.
In treating cast iron, the metal may be in the form of blocks, bars, or moulded
articles and should be confined in a crucible or retort or placed upon the hearth of
a furnace, where it can be heated to the proper degree without melting and can
be subjected to the action of the gases evolved from the liquid or liquids
employed.
Such liquid or liquids can be decomposed in the furnace, crucible or retort,
either by direct contact with the heated metal or independently of such contact,
or the decomposition may be effected in a separate vessel and the gases conducted
thence to the furnace, crucible, or retort containing the heated iron.
The result of the treatment is to eliminate a portion of the carbon from the
iron in the form of carbonic oxide (CO) and to change the form of the remaining
carbon, the nitrogen and hydrogen gases also having effect in the treatment, and
probably entering into the composition of the resultant steel.
In carrying out the invention, the quantity of the liquid to be used and the time
during which the treatment is continued depend upon the bulk of the metal under
treatment and the extent of conversion required, increased bulk of material
requiring an increased quantity of liquid, and the extent of conversion being
greater or less, according as the treatment is continued for a longer or shorter
period.
As an instance, however, of what can be done in the practical carrying out of
our invention, we may say that, in the treatment of ordinary white iron, the use of
30 ounces of the liquid to every 100 pounds of the iron will give good results, an
addition of 32 ounces of carbon being made when wrought iron or low steel is being
treated for the increase of carbon therein.

page_text: In some cases, the liquid employed may contain other gases besides nitrogen,
hydrogen and oxygen, for instance, nitro muriatic acid may be employed, the
decomposition of such acid developing chlorine as well as nitrogen, hydrogen and
oxygen, the latter, however, being the effective gases in the treatment.
Dated this 14th day of June 1894.
ABEL & IMRAY,
Agents for the Applicants.
Improvements in Methods of Partially Decarbonizing and Converting
Iron.
We, SAMUEL HUFTY, of 46, North Third Street, in the City of Camden,
State of New Jersey, United States of America, Accountant, and JOSEPH KAY
CALDWELL, of 37, West Tulpehocken Street, in the City of Philadelphia, State
of Pennsylvania, United States of America, Mechanical Engineer, 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 :-
The object of our invention is to remove a certain percentage of carbon from
solid forms of cast iron in which the carbon is present in such proportion as to
render the metal hard and brittle, the result of our invention being to convert the
cast iron into steel of such ductility that it can be shaped, hammered, drawn or
rolled, or can be tempered in order to form cutting tools, or for other purposes for
which tempering is usually employed, our invention being of special value in treating
articles cast in the form in which they are to be used.
The main feature of our invention consists in subjecting the metal, while highly
heated but still considerably below the point of fusion, and therefore retaining its
solid form, to the action of the gases resulting from the decomposition, by heat, of
nitro-muriatic acid. This acid (aqua-regia of commerce) is a very powerful
oxidizing agent, differing in its action from either nitric acid or muriatic acid, and
we have found that the gases resulting from its decomposition under heat, have the
effect of attracting and removing carbon in the form in which the same is found
in cast iron, and of doing so in a much shorter time than any of the other
decarbonizing agents which have been proposed for the purpose and with which we
are familiar.
The metal may be in the form of blocks, bars, or moulded articles and should be
confined in a crucible or retort or placed upon the heath of a furnace, where it can
be heated to the proper degree without melting and can be subjected to the action
of the gases evolved from the acid.
The acid can be decomposed in the furnace, crucible or retort, either by direct
contact with the heated metal or independently of such contact, or the decomposition
may be effected in a separate vessel and the gases conducted thence to the furnace,
crucible, or retort containing the heated iron.
The decomposition of the acid yields oxygen, nitrogen, hydrogen and chlorine,
and the result of the treatment is to eliminate a portion of the carbon from the
iron in the form of carbonic oxide (CO) by reason of the action of the oxygen,
and to change the form of the remaining carbon, the nitrogen and hydrogen gases
also having effect in the treatment, and probably entering into the composition of
the resultant steel.
In carrying out the invention, the quantity of the acid to be used and the time
during which the treatment is continued depend upon the bulk of the metal under
treatment and the extent of conversion required, increased bulk of material

page_text: requiring an increased quantity of acid, and the extent of conversion being greater
or less, according as the treatment is continued, for a longer or shorter period.
As an instance, however, of what can be done in the practical carrying out of
our invention, we may say that, in the treatment of ordinary white iron, the use of
30 ounces of the acid to every 100 pounds of the iron will give good results.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, we declare that what we
claim is :-
The herein described process of partially decarbonizing cast iron by subjecting
the solid metal to the action of high heat and the gases resulting from the
decomposition of nitro-muriatic acid, substantially as herein described.
Dated this 14th day of March 1895.
ABEL & IMRAY,
Agents for the Applicants.