Method of Determining the Quality or Temper of Iron and Steel.
Year: 1889

page_text: Date of Application, 30th Jan., 1889
Complete Specification Left, 22nd Oct.. 1889-Accepted. 7th Dec., 1889
PROVISIONAL SPECIFICATION.
Method of Determining the Quality or Temper of Iron and Steel.
I, CARL AUGUST CASPERSSON, of Forsbacka, Sweden, Engineer, do hereby declare
the nature of this invention to be as follows:-
-
As the temper of iron and steel, as is well known, not only depends on the
percentage of carbon, but also on the percentage of other substances met with in
common iron and steel such as silicon, manganese, phosphorus etc., it has been
necessary, at iron and steel works, to determine the temper by forging tests. These
tests require, however, for the higher temper at least, great skill and many years of
practice.
The present invention relates to a method of testing, which renders these difficult
forging tests unnecessary. It is founded on the fact that if an electrical current is sent
through a bar of iron or steel of a certain cross-section, the higher the temper of the
latter is, the more rapidly is the bar melted by the current, whatever the substances
may be that are contained in the iron, and that may produce the temper.
The test can be made either by comparing the effect of the electrical current on the
metal that is to be tested, with its effect on other iron or steel of a known temper, or
by measuring the strength of the current requisite to fuse the metal which is to be
tested, and then calculating the temper from this datum.
For carrying out the method of testing according to the first manner, so called
normal steel" of known temper is procured in as many different samples as may be
desirable and necessary to carry out the tests, and from this normal steel, by forging
or rolling or drawing, suitable sized normal pieces are inade, the minimum cross
section of which must be alike in all. When a test is to be made, one or more test
pieces are taken off the iron or steel in question, and wrought in like manner as the
normal steel, and is given a minimum cross section, which is identical with that of the
normal steel samples.
The test-piece and one of the normal steel pieces, the temper of which is considered
as nearest the test piece, are inserted in the electrical circuit of a dynamo machine or
other source of electricity and the current is turned on. Both the test piece and the
normal steel piece then become heated, and the harder of the two becomes most
heated, and fuses if the current is allowed to continue long enough. By repeating
such comparing tests with pieces of normal steel of different temper, the temper of
the metal which is to be tested can be determined with sufficient accuracy and in a
very short time.
The test can also be made by placing several normal steel pieces of different temper
together with the test piece in the electric circuit, the current being then turned on
until the hardest of the pieces fuses. This piece is then removed, and the circuit
closed, then the current again turned on, when the piece next in temper fuses, and so
on. This process is repeated until the test piece itself is fused, when it is ascertained
that its temper lies between that of the normal steel piece which had just before
been fused, and that of the normal steel piece next in temper which has not
fused.
In order to save time as also to economise the pieces of normal steel, the last
mentioned test may be modified so far that the current be regulated from the
commencement of the test, so that none of the pieces are allowed to fuse, but the
current be only permitted to continue until the hardest pieces are of a more or less
red or brown colour, after which all those pieces are uncoupled, which are of a
lighter colour than the test piece, and the test than proceeded with as described
above.
For accomplishing the testing according to the second manner, the strength of the

page_text: current requisite for fusing pieces of normal steel of equal minimum cross-section and
of different temper must be first determined by an ampère meter and a specially
prepared scale. A test piece of the iron or steel to be tested is then made up of the
same minimum cross section as the before mentioned pieces of normal steel. This test
piece is inserted together with an ampère meter'in an electric circuit, the current is then
turned on until the sample or test piece fuses, and the position of the ampère meter is '
observed at the moment of melting.
By means of the before mentioned scale, the temper can then be easily
determined.
Dated this 20th day of Jonuary 1889
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Method of Determining the Quality or Temper of Iron and Steel.
I, CARL AUGUST CASPERSSON of Forsbacka, Sweden, 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 :-
As the temper of iron and steel, as is well known, not only depends on the
percentage of carbon, but also on the percentage of other substances met with in
common iron and steel, such as silicon, manganese, phosphorous etc., it has been
necessary at iron and steel works to determine the temper by forging tests. These
tests require, however, for the higher temper at least, great skill and many years of
practice.
The present invention relates to method of testing which renders these difficult
forging tests unnecessary. It is founded on the fact that if an electrical current is
sent through a bar of iron or steel of a certain cross section, the higher the
temper of the metal is the more rapidly is the bar melted by the current whatever
the substances may be, that are contained in the iron, and that may produce the
temper.
The test can be made either by comparing the effect of the electrical current on the
metal that is to be tested, with its effect on other iron or steel of a known temper, or by
measuring the strength of the current requisite to fuse the metal which is to be tested,
and then calculating the temper from this datum.
For carrying out the method of testing according to the first manner, so called
normal steel of known temper is procured in as many different samples as may be
desirable and necessary to carry out the test, and from this normal steel by forging
or rolling or drawing, suitable sized norinal pieces are made, the minimum cross
section of which must be alike in all. When a test is to be made, one or more
test pieces are taken off the iron or steel in question, and wrought in like
manner as the normal steel and is given a minimum cross section which is identical
with that of the normal steel samples.
The test piece and one of the normal steel pieces, the temper of which is considered
as nearest the test piece are inserted in the electrical circuit or a dynamo machine or
other source of electricity and the current is turned on. Both the test piece and the
normal steel piece then become heated, and the harder of the two becomes most
heated, and fuses if the current is allowed to continue long enough.
By repeating such comparing tests with pieces of normal steel of different temper
the temper of the metal which is to be tested can be determined with sufficient
accuracy and in a very short time.
The test can also be made by placing several normal steel pieces of different temper
together with the test piece in the electric circuit the current being then turned on
until the hardest of the pieces fuses. This piece is then removed, and the circuit
closed, then the current again turned on when the piece next in temper fuses and
so on.

page_text: This process is repeated until the test piece itself
fused, when it is ascertained that
ts temper lies between that of the normal steel piece which had just before been fused,
and that of the normal piece next in temper which has not fused.
In order to save time as also to economise the pieces of normal steel, the last
mentioned test may be modified so far that the current be regulated from the com-
mencement of the test so that none of the pieces are allowed to fuse, but the current
or less red
be only permitted to continue until the hardest pieces are of a more
or brown colour, after which all those pieces are uncoupled which are of a
lighter colour than the test piece and the test then proceeded with as described
above.
Instead of fusing the test piece and the normal steel pieces, thermometers, detonating
matter or the like may be applied to the different pieces through which the electric
current is sent, and by reading the thermometers or observing the order in which the
detonating matter etc. ignites, the temper of the test piece may be determined without
fusing any of the pieces inserted in the circuit.
When using detonating matter, the test piece and normal steel pieces of various
temper, all drawn or rolled to wires of equal diameter, are inserted in a circuit and
detonating matter laid upon each piece, and this must be laid on the middle of the piece
equally distant from the fixing points.
When subjected to a current of equal strength the detonating matter on the piece of
highest temper will always be ignited first, and afterwards the ignition continues on
following the scale of temper downwards; when the turn comes to the test piece its
temper is thus determined. If it be desired to determine the temper more accurately,
the test piece and the normal steel piece or pieces, the detonating matter of which
ignited at about the same time, are subjected to the current till the fusing point is
reached.
For accomplishing the testing according to the second above described manner,
the strength of the current requisite for fusing pieces of normal steel of equal
minimum cross section and of different temper must be first determined by an ampère
meter, and a scale specially prepared by noting down the different positions of the
ampère meter in fusing off the said normal steel pieces of known temper. A test
piece of the iron or steel to be tested is then made of the same minimum cross section
as the before mentioned pieces of normal steel. This test piece is inserted together
with an ampère meter in an electric circuit, the current is then turned on until the
sample or test piece fuses and the position of the ampère meter is observed at the
moment of melting.
By means of the before mentioned scale, the temper can be easily determined.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
The method of determining the temper of iron and steel by means of an electric
current, substantially as described.
Dated this 22nd day of October 1889.
ADRE C. IMDAV
ABEL &
IMDAV
Agents for the Applicant.