Improvements in and relating to Process of Manufacturing Sheet Metal,
Year: 1899

page_text: Date of Application, 13th June, 1899-Accepted, 9th Sept, 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Process of Manufacturing Sheet
Metal,
I, EVAN JAMES FRANCIS, Sheet Roller, of McCargo Street, New Kensington,
in the County of Westmoreland and State of Pennsylvania, United States of
America, 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 a process for the manufacture of sheet metal. One of
the greatest difficulties encountered in connection with the manufacture of sheet
iron and steel for tinning and other purposes is due to the oxidation of the iron
or steel either in the original form of bars or plates or when reduced to sheets.
To remove any scale caused by the oxidation of the metal it has to be carefully
annealed and pickled at different stages of the process.
If the sheets when
reduced are to be tinned or coated with another soft metal or alloy, unless all
oxide has been removed previous to the dipping or coating operation, an im-
perfect sheet will result, as the coating metal will not take effect on the spots
where oxidation has taken place and where any scale remains.
The object of my invention is to provide a process of making sheet metal in
which the liability of the oxidation of the metal is practically eliminated, so that
the sheet when finished, whether to be finally coated with another metal or not,
will be free from oxide and the danger of oxidation, while at the same time the
sheet metal possesses great toughness and ductility for stamping and other uses in
the arts.
To these ends my invention consists, generally stated, in coating the iron or
steel body from which the metal sheet is to be formed with nickel, as by elec-
trolysis, heating the metal body thus coated, and then reducing the same to sheet
metal of desired gauge; and, if desired, in coating the sheet metal so produced
with tin or other soft metal, in which case the invention includes certain
economical treatment of the sheets in the tinning or like process.
In practising my invention I take iron or steel in the form of billets, bars, or
plates and remove any oxide which it may have on its surface. This is prefer-
ably done in the ordinary manner by introducing the metal into a suitable acid
bath, or what is commonly known as pickling. In this manner any oxide or scale
on the metal is removed. Where my invention is to be carried out in connection
with the manufacture of tin plate, this pickling may be accomplished very
economically by the use of the refuse from the pickling pots into which the sheets
are introduced preparatory to the tinning operation.
The metal body when cleaned, as above, is then coated with nickel. This
may be accomplished in any suitable way. I prefer to insert the bars or plates
in a suitable bath, and deposit the nickel thereon by electrolysis, in this way
obtaining a comparatively thin coating of the metal upon the metal bar or plate.
The nickel completely envelops the iron or steel and finds its way into the seams
and pores of the metal from which the oxide has been removed. The well-
known quality of nickel to resist oxidation and corrosion is thus imparted to the
surface of the iron or steel, so that the formation of rust or scale is avoided.

page_text: The metal thus coated is then heated to the proper degree and rolled or
hammered to reduce said metal to sheets of the required thickness or gauge. The
melting point of the nickel is so high that the coating is not affected in raising
the metal body to a rolling heat. The bars or plates and the thicker sheets
formed from them in reducing the metal to the desired gauge, can also be rolled
in piles without liability of the nickel coating of any two bars or sheets adhering,
and they can therefore be handled in the same way as in rolling ordinary sheet iron.
while the sheets in the packs formed are easily separated. By the rolling of the metal,
the nickel is driven or forced into the pores of the metal, increasing its density
as well as its power to resist oxidation. In the rolling operation the coating
of nickel is of course spread out in a thinner coating, but even when not perceptible
to the eye it apparently gives this protection against oxidation. The nickel when
pressed or forced into the pores of the iron or steel adds toughness and ductility,
so that the sheet-metal made in this manner can be bent or twisted without
fracture or rupture, which gives it great advantage as a stamping iron. The
original coating applied by electrolysis may be itself quite thin, and as the sur-
faces of the bar are small as compared with the finished sheet, the cost of applying
the nickel coating is small.
The sheets produced as above can be coated with tin, lead, spelter, or other
suitable soft metal coating. When they are to be coated with tin, the sheets are
first pickled to remove any possible oxide and then placed in annealing boxes and
introduced into a suitable furnace to be annealed in the ordinary manner. After
they have been annealed they are passed through the cold rolls. They are then
taken to the tin-house where they may be tinned by any of the well known
methods.
By my process, on account of the greater ductility of the sheet metal, I am
enabled to dispense with the second annealing which follows the cold-rolling in
the ordinary process of manufacturing tin-plate.
The preparation of the metal for tinning by first rendering it practically non-
oxidizable is of great importance, as the sheets are practically free from oxide
and scale and better adapted to receive the tin. There is a clean surface to take
the tin, so that no spots remain uncovered but a smooth even coating of tin is
obtained. Again, the tin-plate produced from metal treated as above will have
all the increased toughness and ductility which such a metal is found to possess,
so that a high grade of tin plate is produced for stamping and other purposes.
Terme-plate can also be made in the same manner as tin plate, which will give
a roofing plate capable of affording greater resistance to the oxidation and
corrosion from exposure to the weather.
I wish to include within the scope of my invention any process of coating iron
or steel with nickel and forcing or driving the nickel into the pores of the metal
in reducing it to sheets in such manner as to enable said metal to resist oxidation
entirely, or in part, as well as to increase the toughness and ductility of the metal.
It is apparent that my invention may be applied to the manufacture of hoop
and band iron or steel, the quality of toughness and ductility having markedl
advantages in such case.
By my invention ordinary Bessemer steel when treated as above takes the place
of the more expensive open-hearth 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 process of making sheet-metal consisting in coating an iron or steel body
with nickel, heating the body so coated and reducing it to a sheet.
2. The process of making sheet-metal, consisting in depositing nickel on an
iron or steel body by electrolysis, heating the body so coated, and reducing it to
sheet metal.
3. The process of making sheet metal, consisting in cleaning an iron or steel

page_text: body from oxide, coating it with nickel, heating the body so coated and reducing
it to sheet metal.
4. The process of making sheet-metal, consisting in coating bars of iron or
steel with nickel, piling said coated bars and heating and rolling them to sheeis.
5. The process of making sheet metal, consisting in coating an iron or steel
body with nickel, heating the body so coated and reducing it to sheets, and after-
wards coating the sheets thus produced with soft metal.
6. The process of making sheet-metal, consisting in coating an iron or steel
body with nickel, heating and reducing the body so coated to sheets, annealing
said sheets, passing them through cold rolls, and finally coating the sheets with
soft metal.
7. The process of making sheet-metal, consisting in coating an iron or steel
body with nickel, heating and reducing the body so coated to sheets, pickling
and annealing said sheets, passing them through cold rolls, and finally coating
them with soft metal.
Datod this Thirteenth day of June 1899
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.