Improvements in the Welding of Metal.
Year: 1890

page_text: te of Application 25th Mar., 1890-Accepted, 28th June, 1890
COMPLETE SPECIFICATION.
Improvements in the Welding of Metal.
I, ROBERT JOHNSON TILFORD, of Louisville, Jefferson County, in the State of
Kentucky, United States of America, 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 :-
My invention relates to an improved process of welding iron to steel or steel to
steel; in both cases the sections to be united having different percentages of carbon."
Heretofore many attempts to perfectly weld such metals have been attempted, but,
in so far as I am aware, without success. The most common method known to me
consists in arranging steel and iron in a pile, subjecting said pile to a welding heat
and thereafter subjecting it to rolling hydraulic pressure, hammering, or all. The
product obtained by such methods is suitable for some purposes, but generally
speaking is commercially unsatisfactory, by reason of the fact that when subject
to shocks or concussions above a certain degree has its coherency destroyed and the
iron split or separated from the steel, the result being that the product is fractured.
By my improved process 1 avoid the objections attendant upon previous methods, and
am enabled to produce a compound product, in which the welding of the two metals
to be united is so thoroughly effected that their allied faces become practically
obliterated and the metal homogeneous thereat.
In conducting welding operations in accordance with my said process set forth
herein, I have found that important and valuable results are also obtained by
employing a steel previously treated in accordance with the United States Letters
Patent No. 397,476, issued February 5th 1889, to myself and one H. M. Redemann,
to which reference may be had for a more complete understanding of the said process
and the condition of the product before and after such treatment. By reference to
said patent, it will be found that the improved process set forth and described therein
relates to subjecting Bessemer and other low grades of steel heated to such heat as
may be desired, to a previously prepared liquid bath of such character that the contact
of metal and liquid bath induces hydrocarbon gases, which are absorbed or taken up
by the metal, the latter being permitted to remain in such bath at pleasure or until
substantially cool or until such reduction of heat is made that it will no longer take
up hydrocarbon gases. The results consequent upon such patented process are stated
to be inexpensive production of a higher grade of steel, minimum degree of labor
involved therein and the procurement of a product having a molecular change from a
coarse grain to a fine grain or silky fracture, to increase tensile strength, elasticity,
toughness and ductility and to greatly increase the carbon. The principal elements of
the bath mentioned are glycerine and water in the proportion of three ounces of
glycerine to one-half gallon of water. To such elements may be added spirits
of nitre, aqua ammonia, chloride of ammonium, sulphate of zinc, sulphate of alumina,
and ammonia. The steps and agents involved in said patented process have been here
detailed, for when the product thereof is used in the process forming the subject-
matter of the present application, such steps and agents constitute a sub-process and
will be directly related thereto. It is further proper to here state that one of the
advantages secured for steel treated by said patented process is its capacity for
resisting impairment by reheating, if such reheating is conducted at any temperature
representing a degree of heat below what would be required to effect, in part or
wholly, the destruction of the steel qualities of the article.
In carrying out the present process in the event of the union of iron to steel, two
or more furnaces are employed, and the iron, which is the wrought iron of commerce,
is heated in one furnace to a high degree equivalent to a dazzling white or just below
its melting point. The steel to be united therewith heated in a separate furnace to a

page_text: degree approaching incipient redness, is placed in contact with the iron, the surfaces,
if desired, having been previously fluxed or otherwise prepared to contribute to the
union of the two metals. The relatively arranged iron and steel are then placed in
either of the two furnaces mentioned, or in a separate furnace, and are then gradually
heated until the steel assumes substantially a bright red color, at which period the
metal is either hammered, or rolled, or both to condense and reduce it completely into
a compound product in which the iron and steel exist in a perfect union or weld. By
heating the iron to a degree so much higher than the steel, contact with the steel will,
by reason of its greater heat, begin to withdraw or transfer a part of the carbon of
the steel, which becomes incorporated in the said iron or portion of said iron at about
the instant the two metals are brought in contact, the union finally becoming so
complete that the steel merges into the iron regularly and evenly, and thereby avoids
the weakness that would exist were the junction of the two more sharply defined.
It will be understood that by heating the iron to the high degree mentioned and the
steel to an incipient redness, and then arranging them relative to each other, it will
not be necessary in the succeeding operations required to reduce and complete the
compound article; to heat the external faces of the steel to an excessive extent in
order to raise the covered face or portion adjacent to the iron to a welding degree.
By such practice I am enabled to avoid the burning out or deterioration of the steel
which generally attends the practice where the metals are arranged in a pile before
heating.
I do not wish to be understood as limiting myself in the present process to the
welding with iron or low grade steel, of a steel produced by said patented process
previously mentioned, as it will be quite obvious that other kinds of steels of varying
quality or grade may be successfully welded to each other or to iron.
In giving the steel a preliminary heating, where considered necessary, of com-
parative low degree before arranging it relative to the iron, undue or sudden expansion,
when brought into proximity to the highly heated iron, is avoided, and hence liability
to cracking or fracture is avoided.
As before stated, the process is applicable for securing a regular and complete
welding of high and low grade or of steel generally with iron.
In the within description, when iron is mentioned the wrought iron of commerce is
referred to, and when such iron is to be united with steel, it will be with either of the
qualities known as high and low grade cast steel of the Bessemer production. When
steel is to be united to steel, the description contemplates two independent steel
sections having pronounced differences of carbon, thus constituting the same relative
relation and character that exists between wrought iron and steel.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The improved step in the art of uniting wrought iron and steel or steel to steel
having different percentages of carbon; the same consisting in heating the metal lowest in
carbon to a degree equivalent to white heat, heating the metal highest in carbon to an
incipient red heat and thereafter placing the two differently heated metals in contact,
substantially as set forth.
2. The process of uniting wrought iron and steel or steel to steel having different
percentages of carbon; the same consisting in heating the metal lowest in carbon to
a white heat, heating the metal highest in carbon to an incipient red heat, placing
both metals in contact in a furnace and heating to a welding beat, and finally
subjecting to a further welding action, substantially as set forth.
3. The process of uniting, steel with a metal having a comparative lower percentage
of carbon, consisting in first subjecting steel at a white heat to the action of a liquid
bath evolving hydrocarbon gases, heating the metal low in carbon to a high
temperature, and then arranging the steel relative thereto, and finally uniting,
substantially as shown and set forth.
4. The process of uniting steel with a meal having a comparative low percentage

page_text: of carbon, consisting in first subjecting steel at a white heat to the action of a liquid
bath evolving hydrocarbon gases, until said steel reaches the limit of its absorption,
then heating the metal low in carbon to a high temperature, moderately heating the
steel, relatively arranging it with respect to the highly heated metal, and finally uniting,
substantially as shown and set forth.
Dated this 95th day of March 1800
W. P. THOMPSON & BOULT,
Agents for the Applicant.