Improvements in Preparing Iron and Steel Sheets or Plates Previously to Galvanizing them (that is Coating them with Spelter).
Year: 1888

page_text: Date of Application, 14th Nv., 1888
Complete Specification Left. 2nd Aug. 1889-Accented 7th Sent 1889
PROVISIONAL SPECIFICATION.
Improvements in Preparing Iron and Steel Sheets or Plates
Previously to Galvanizing them (that is Coating them with
Spelter).
We, DAVIES BROTHERS AND COMPANY (Limited) of The Crown Galvanizing Works,
Wolverhampton in the County of Stafford, galvanized iron manufacturers, and
EDWARD ALBERT DAVIES, managing director of the said Company, do hereby declare
the nature of this invention to be as follows:-
This invention has for its object to prepare metal sheets or plates in such a manner
that a less waste of coating metal results in coating the surfaces than when the
sheets or plates are prepared according to the ordinary methods..
According to this invention the sheets or plates are cold rolled subsequently to
being pickled and previously to being coated in the bath of molten metal.
In employing the invention preparatory to galvanizing iron or steel sheets or.
plates such sheets or plates are cold rolled immediately they have been washed after
being pickled; and after being cold rolled the sheets or plates are immediately
immersed again in water and are then passed into the galvanizing pot; or the sheets.
or plates may be cold rolled under water so as to avoid exposing them to the air
from the time they are passed into the washing tank until they are ready to be
dipped into the galvanizing pot.
It is found that when the sheets are cold rolled between the pickling and coating.
operations a less quantity of coating metal is taken up by each sheet or plate than
when the cold rolling is not resorted to, and thus considerable economy is effected.
It is believed that the result obtained is due to a certain closing up of pores or cells
which have been formed in the substance of the metal by the action of the acid
employed in pickling the sheets or plates, and that the metal saved by the employ-
ment of this invention is such as is ordinarily wasted in simply filling up the hollows
or interstices in the surfaces of the sheets or plates.
Dated this 13th day of November 1888
STEPHEN WATKINS,
Wolverhampton and Walsall, Agent for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Preparing Iron and Steel Sheets or Plates
Previously to Galvanizing them (that is Coating them with
Spelter).
We, DAVIES BROTHERS AND COMPANY (Limited) of the Crown Galvanizing Works,
Wolverhampton in the County of Stafford, galvanized iron manufacturers, and
EDWARD ALBERT DAVIES, managing director of the said Company, 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:-
In the art or process of galvanizing iron and steel sheets or plates, as heretofore
practised, they are first pickled, then washed in water, and finally dipped in a bath
containing the molten spelter which adheres to them on their removal from the bath
and forms a permanent coating which protects the iron or steel from corrosion. The
pickling produces a roughened surface of the sheets or plates, and the portions of the
spelter which fill up the pits or hollows in the surface are to a large extent wasted ;
and as spelter is a very expensive metal a considerable loss results. Moreover, owing
to the roughness of the pickled surface, the surface of the coating which is formed
thereon by the galvanizing process is not so smooth as is desirable.
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page_text: Now, the object of this invention is to overcome these defects, at least in a very
considerable degree, and this is accomplished by cold-rolling the iron or steel sheets
or plates subsequently to pickling them in the usual manner and previously to coating
them in the bath of molten metal.
The sheets or plates are kept under water after being pickled until they are passed
through the cold rolls, so as to avoid oxidation by the atmosphere; and it is
preferred, for the same purpose, to keep them under water after rolling, until they
are dipped in the galvanizing bath. The sheets or plates should be exposed as little.
as possible to the influence of the atmosphere between the pickling and dipping
processes; and it is preferred to keep water running on the rolls so that the sheets
or plates may be kept wet during the rolling process. This may be conveniently
effected by supplying the water through a perforated pipe fixed longitudinally over
the upper roll.
As freshly pickled sheets or plates may require to be washed before all the
previously pickled and washed sheets or plates have been cold rolled, it is convenient
to store the pickled and washed sheets or plates in a bath of water, to which they
are moved from the washing bath; and this store bath may be placed with one end
just in front of the rolls so that the sheets or plates contained in such bath are
conveniently fed therefrom to the rolls. The sheets or plates are placed in a
corresponding store bath immediately after passing through the rolls, where they
remain until drawn out for dipping into the molten coating metal. In order to keep
the work separate, a separate store bath for receiving the sheets or plates from the
rolls may be used for each galvanizing pot; but a common store bath for receiving
the pickled. and washed sheets or plates previously to cold rolling them may be
employed, as the sheets or plates from one washing bath may be rolled before those
of another washing need to be removed from the bath in which they are washed.
The cold rolling appears to have the effect of closing up in a greater or less
degree the pores or cells which have been formed in the substance of the metal by
the action of the acid employed in pickling, and it produces a much smoother surface
than is left as a result of the pickling.
There is nothing special in the apparatus employed. The rolls are of the usual
character of rolls employed for cold-rolling metal, and are operated in the same or
analogous manner. The rolls may be immersed in the bath of water within which
the sheets or plates are stored previously to being cold rolled, if desired, so that the
rolling is performed entirely under water. In such case the rolls may be carried and
operated in a manner similar to that of the rolls employed in roller galvanizing
baths. There is, however, no need for the extra complication in apparatus thus
involved.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is
Treating the surfaces of iron and steel sheets or plates, previously to galvanizing
them, by cold rolling subsequently to the pickling process.
Dated this 1st day of August 1889
OZITA
STEPHEN WATKINS,
Wolverhampton, Agent for the Applicants.