IMPROVEMENTS IN THE MANU- FACTURE OF CHILLED ARTICLES OF STEEL AND IRON
Year: 1880

page_text: LETTERS PATENT to Henry Springmann, of 109-110, Gneisenau Strasse,
Berlin, S.W., Prussia, for an Invention of "IMPROVEMENTS IN THE MANU-
FACTURE OF CHILLED ARTICLES OF STEEL AND IRON." A communication
from C. F. A. Quenscll, of Teichhütte, near Gittelde, Brunswick.
COMPLETE SPECIFICATION filed by the said Henry Springmann at the
Office of the Commissioners of Patents on the 9th August 1880.
HENRY SPRINGMANN, of 109-110, Gneisenau Strasse, Berlin, S.W., Prussia.
IMPROVEMENTS IN THE MANUFACTURE OF CHILLED ARTICLES OF STEEL AND
IRON." A communication from C. F. A. Quensell, of Teichhütte, near Gittelde,
Brunswick.
This Invention relates to improvements in the method of manufacture of articles
such as armour plates, shot and shell, railway crossings and switches, car-wheels,
and other castings produced in a mould of cast iron, and the object is, firstly, to
impart to such articles a maximum of resisting power against dead blow or wear
and tear; and, secondly, to remove or obviate any tension or partial strain which
so frequently results from the usual way of manufacture of chilled castings.
I am aware that for the same object it has been recommended to artificially cool
chilled castings, either in the original mould or in ovens, but such proceedure is
exposed to uncontrolable irregularities, and creates thereby defects in property
common to cast iron goods.
In order to obtain my first named object I melt in a copula furnace, Martin oven,
or other known furnace or oven, together with pig iron, or an appropriate mixture
of grey and white pig iron, by preference charcoal pig iron, or so called cold blast,
from 5 to 30 per cent. of cast steel. If I produce armour plates I generally use
grey and white pig iron in equal quantities, or in quantities according to the
specific properties of the brand, or the properties desirable to be obtained; 35 to
40 per cent. of grey pig iron and an equal quantity of white pig iron added to 20
to 30 per cent. of steel will give a good mixture for this purpose. In comparison
herewith the mixture for shot and shell will have to contain less steel, but will
generally require a larger quantity of grey pig iron in proportion to the white pig
iron. Some other articles, such as railway crossings and switches, will not require
Dis 21

page_text: any admixture of white pig iron, or only a few per cent. I prefer for such objects
a mixture consisting mainly of grey pig iron with an addition of from 15 to 30
per cent. of steel.
In carwheels the chilled hardening must penetrate deeper than
in crossings, and for this purpose I admix 5 per cent., or more, of white pig iron
with the charge of the oven.
As it is practically difficult or improfitable to melt more than about 30 per cent.
of cast steel together with 70 per cent. of pig iron in a copula or other furnace or
oven, I may also produce or melt the proportionate admixture of cast steel in
crucibles, a Martin oven, or by other known means, and then mix it with the
appropriate charge of melted pig iron in a tank or vessel before it is let into
the mould.
This is especially recommendable if large quantities are to be dealt
Instead of an admixture of grey and white pig iron, or either of the two, one
may of course apply what is termed mottled pig iron of known properties; it will
however always be preferable to use either grey or white pig, or a certain mixture
of known brands of such pig irons.
with.
To obviate or remove any undue tension or strain in castings produced by
pouring the above described mixtures into cast iron or other moulds used for the
manufacture of chilled surfaces, I remove the castings when they have sufficiently
set from the mould to retorts, kilns, or ovens, suitable to give the whole casting a
more or less dark red heat equally all over, then let the casting remain in this
state in such retort, kiln, or oven for a length of time appropriate to its weight or
dimension, and finally allow it to cool gradually.
Castings so produced will have the peculiarities of what are known as chilled
castings, but will prove to possess a far greater strength or resisting power and
none of the defects of chilled castings manufactured in the ordinary way.
Having thus described the nature and object of this Invention, and the manner
in which it is to be carried out in practice, as communicated to me by my corre-
spondent, I hereby claim as new and important features of the same,-
1. The manufacture of chilled castings from a mixture of melted white and grey,
or melted mottled, or melted grey pig iron as one component, and melted steel as
the other component, as and for the purpose specified.
2. The application of red heat to such chilled castings in a retort, kiln, or oven
after they are removed from the mould, as and for the purpose described.
In witness whereof, I, the said Henry Springmann, have hereunto set my
hand and seal, this Sixth day of August, in the year of our Lord One
thousand eight hundred and eighty.
H. SPRINGMANN. (L.S.)