A New or Improved Process for Determining the Carbonaceous Value of Iron and Steel.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
A New or Improved Process for Determining the Carbonaceous
Value of Iron and Steel.
I, GUSTAV WILHELM PEIPERS, of 46 Freiheilstrasse, Remscheid, German
Empire Engineer do hereby declare the nature of this invention to be as
follows:-
My invention relates to a new or improved process, in combination with certain
well known chemicals, for determining, by comparison the amount of carbon
contained in any piece of iron or steel, irrespective of its weight or bulk, the
carboniferous value of which is unknown, my said invention having for its object
to obtain such information more quickly, easily, with less expense, and greater
certainty than has been possible by the methods and means hitherto adopted.
65
It is well known from previous experiments that the natural hardness, temper,
elasticity and flexibility of the finished metal, is, to a very great extent, governed by
the amount of carbon contained therein, and although every care may be exercised
in the manufacture of iron and steel, that it may contain a certain and given
quantity of carbon, through unknown or unpreventable causes, the finished metal
may contain a greater or lesser quantity than that desired, and to determine this I'
am not aware that there has hitherto been found a better system than that known
as Eggertiselers test," which consists of dissolving a piece of iron of a given or
known weight in nitric acid, and according to the colour of the resultant liquid the
amount of carbon may be determined. But this system of quantitative analysis
requires a great amount of technical knowledge, time and money in its execution,
and coupling this with the fact that it has now grown customary between buyers
and sellers of iron and steel, for the former to ask, and the latter to guarantee, the
percentage of carbon contained in the metal, has led me to devise the present simple
system forming the subject of my invention."
For the purposes of my invention I employ the use of tablets made of any
suitable acid proof material, and upon which a piece of iron or steel will make a
mark, such for instance as porcelaine, china, quartz, missisipi stone, light_agate,
ground flint glass etc., but preferably porcelaine, and upon such a tablet I trace
marks with the piece of iron or steel to be tested, (in the same way as might be done
with a lead pencil), such marks will then be found to consist of a mixture of light
grey parts (iron) and dark parts (carbon). I also employ a number of pencil
pointed iron or steel rods each of which contains a different but known percentage
of carbon, such percentage being stamped thereon, and with one or two of such rods,
(the amount of carbon in which is as near as can be judged the nearest to the per-
centage of carbon presumed to be contained in the piece of metal to be tested,) I
make similar tracings upon the said and self same tablet, parallel with the tracings
from the metal to be tested. The said tablet would then be immersed in a bath
containing any suitable liquid capable of dissolving the iron in the tracings with the
result, that what remains would be carbon only, and by comparing the residue of
the tracing of the metal being tested, (which contains an unknown quantity) with
the residue from the tracing made by the said rods (which contain a known
quantity), the eye can easily discern so plainly as to with certainty determine a
difference of 0.025 % of the amount of carbon in the metal being tested.

page_text: Referring to the accompanying drawings,
Fig. 1 represents the piece of iron or steel A to be tested.
Fig. 2 are eight pencil pointed rods of steel or iron marked B, C, D, E, F, G, H, I,
respectively each containing a known percentage of carbon stamped thereon.
Fig. 3 is a porcelaine or other tablet J, upon which are tracings A¹ from
Fig. 1, and tracings D' and G' from the pencils D and G respectively.
Fig. 4 illustrates the manner of placing the tablet J in the glass, porcelaine or
other acid proof dish K, with the said tracing downwards, and partly immersed in
the liquid therein.
Fig. 5 illustrates the appearance of the said tracings when the tablet J has been
removed from the bath K.
In making the tracings upon the tablet J, it is essential that the tracings from
the test piece A, and the tracings from such of the pencils Fig. 2 as may be
employed, should be equally dense or dark, as shewn at Fig. 3, and the tablet
when placed in the bath should be allowed to remain there for a few minutes,
or until the iron lustre has disappeared when it would be removed and after
careful washing in water would appear as at Fig. 5.
Referring to Fig. 5 it will be seen that the quantity of carbon in the tracing A'
of the test piece A, Fig. 1, bears no comparison with the tracings D' of the pencil D
which contains 0.15% of carbon, but more nearly with the tracing G₁ of the
pencil G, which contains 0.3% of carbon, but as G₁ is still slightly darker than A',
it is probable that 0.29% of carbon is contained in the test piece A, but in order to
determine this more accurately a magnifying glass may be used for examining the
tablet Fig. 5, when, if equal intensity of colour exists between A' and G', the one
having the coarser grain would contain the greatest percentage of carbon, and by a
suitable choice of the dissolving liquid different forms of carbon may be recognised
by this process, and separate tests may be made for graphite and carbon.
The solvent for the carbon test may consist of suitable proportions of copper,
chloride, chloride of ammonia, or chloride of iron, iodine in iod kali water, or
diluted nitric acid. For graphite tests, nitric acid, sulphuric acid or ascetic acid
may be best employed.
If it is desired to test for carbon and graphite, the following mode may be
adopted.
The tablet Fig. 3 would be first treated with, preferably, chloride of copper, and,
or chloride of ammonia, with the result that the iron only would dissolve and solid
carbon as well as graphite be left behind, when, if the tablet be treated with
sulphuric acid or nitric acid, the amount of graphite would be determined by reason
of the dissolving of the carbon.
Separate normal iron test rods Fig. 2 containing graphite, would by the comparing
process give the amount of graphite.
Dated this 10th da
1005
A New or Improved Process for Determining the Carbonaceous
Value of Iron and Steel.
I, GUSTAV WILHELM PEIPERS, of 46, Freiheilstrasse, Remscheid, German
Empire, 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:—
My invention relates to a new or improved process, in combination with certain

page_text: well known chemicals, for determining by comparison, the amount or percentage of
carbon contained in any piece of iron or steel, irrespective of its weight or bulk,
the carboniferous value of which is unknown, my said invention having for its
object to obtain such information more quickly, easily, with less expense, and
greater certainty than has been possible by the methods and means hitherto
adopted.
It is well known from previous experiments, that the natural hardness, temper,
elasticity and flexibility of the finished metal, is to a very great extent governed
by the amount of carbon contained therein, and although every care may be
exercised in the manufacture of iron and steel, that it may contain a certain and
given quantity of carbon, through unknown or unpreventable causes, the finished
metal may contain a greater or lesser quantity than that desired, and to determine
this I am not aware that there has hitherto been found a better system than that
known as "Eggertiselers test," or "Eggertz method" which consists of dissolving
a piece of iron or steel of a given or known weight in nitric acid, and according to
the color of the resultant liquid the amount of carbon may be determined.
this system of quantitative analysis requires a great amount of technical knowledge,
time and expense in its execution, and coupling this with the fact that it has now
grown customary between buyers and sellers of iron and steel for the former to
enquire, and the latter to guarantee, the percentage of carbon contained in the
metal, has led me to devise the present simple system forming the subject of my
invention.
But
For the purposes of my invention I employ the use of tablets made of any
suitable acid proof material, and upon which a piece of iron or steel will make a
mark, such for instance as unglazed porcelaine, china, quartz, missisipi stone, light
agate, ground fint glass etc., but preferably porcelaine, and upon such a tablet
I trace marks with the piece of iron or steel to be tested, (in the same way as
might be done with a lead pencil) such marks will then be found to consist of a
mixture of light grey parts (iron) and dark parts (carbon). I also employ
a number of pencil pointed iron or steel rods, each of which contains a different
but known percentage of carbon, such percentage being stamped or otherwise
marked thereon, and with one or two of such rods the amount of carbon in which
is (as near as can be judged) the nearest to the percentage of carbon presumed to
be contained in the piece of metal to be tested, I make similar tracings upon the
said and self same tablet, parallel with the tracings from the metal to be tested.
The said tablet would then be immersed in a bath containing any suitable liquid
capable of dissolving the iron in the tracings, with the result, that what remains
would be carbon only, and by comparing the residue of the tracing of the metal
being tested (which contains an unknown quantity of carbon) with the residue from
the tracing made by the said rod or rods (which contain a known quantity) the
eye can so plainly and easily discern and with certainty determine, a difference
of 0.025% of the amount of carbon in the metal being tested.
In order that my invention and the manner of carrying the same into effect may
be fully and clearly understood reference may be made to the drawings which
accompanied my Provisional Specification, of which
Fig. 1 represents, presumably, the piece of iron or steel A to be tested.
Fig. 2 represents eight pencil pointed rods of iron or steel marked B, C, D, E, F,
G, H, I, respectively each containing a known percentage of carbon, such per-
centage being stamped or otherwise marked thereon.
Fig. 3 is a porcelaine or other tablet J, upon which are tracings A' from Fig. 1,
and tracings D¹ and G' from the pencils, say D and G respectively.
Fig. 4 illustrates the manner of placing the tablet J in a glass, porcelaine, or
other acid proof dish or beaker K, with the said tracings downwards and partly
immersed in the liquid therein.
Fig. 5 illustrates the probable appearance of the said tracings upon the tablet J,
when this has been removed from the bath.
In making the tracings upon the tablet J, it is essential that the tracings from

page_text: the test piece A, and the tracings from such of the pencils Fig. 2 as may be
employed, should be equally dense or dark as shewn at Figure 3, and the tablet
when placed in the bath should be allowed to remain there for a few minutes or
until such time as the iron lustre has disappeared, when it would be removed and
after careful washing in water appear, probably, as at Fig. 5.
10°
Upon reference to Fig. 5 it will be seen that the quantity of carbon in the
tracing A' of the test piece A Fig. 1, bears no comparison with the tracings D'
of the pencil D (which contains 0.15 % of carbon) but more nearly with the
tracings G¹ of the pencil G (which contains 0·3% of carbon), but as G' is still
slightly darker than A', it is probable that 0.29 %, or thereabouts of carbon is
contained in the test piece A, but in order to determine this more accurately, a
magnifying glass may be used for examining the tablet Fig. 5, when, if equal
intensity of color exists between A¹ and G¹, the one having the coarser grain
would contain the greatest percentage of carbon, and by a suitable choice of the
dissolving liquid different forms of carbon may be recognised by this process, and
separate tests may be made for graphite and carbon.
The solvent for the carbon test may consist of a solution of 12% or thereabouts
of copper, chloride, or chloride of ammonia, iodine in iod kali water, or diluted
nitric acid. In tests for graphite separate normal iron test rods such as Fig. 2,
containing a known quantity of graphite, would be employed, and having made
tracings from these, and the metal to be tested, upon the porcelaine or other
tablet Fig. 3 in the manner previously described, the said tablet would be first
immersed in the beaker or the like K, containing a solution of chloride of copper
or chloride of ammonia, for dissolving the iron, with the result, that (after washing)
solid carbon and graphite remain, when, if the tablet be then treated with a bath
of sulphuric, uitric or ascetic acid, and again washed, the amount of graphite would
be determined, by comparison as before, by reason of the destruction of the
carbon.
It will be found in practice that to make the said tracings upon the unglazed
porcelaine or other tablet J, is as easy as it would be to make similar marking
with a lead pencil upon paper, saving that a slight excess of pressure would in the
former case be necessary and in most cases, an immersion of two minutes duration
will be found sufficient, to dissolve the iron in the tracings, the subsequent washing
of these in water being to remove the chloride or other solvent therefrom, before
comparison, and according to my invention tracings can be as easily made from
finished articles as with scrap, such as A, as the said finished article would be in
nowise injured in the process. The markings upon the tablet after comparison,
may, if desired, be permanently retained for future reference or record of analysis,
by coating the tablet and markings with suitable varnish, or if the said markings
are to be entirely removed, this may be effected by the use of emery, or dissolved
off by nitric or hydrochloric acid.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
First. In an improved method of and means for determining the amount of
carbon or graphite or both contained in iron and steel, the use and application of
the herein described process, in combination with the materials and substances
employed in connection therewith substantially as herein set forth and shewn.
Second. In an improved process for determining the amount of carbon or
graphite or both in iron or steel, the employment of any number of pencils of
metal such as B, C, D, E, F, G, H and I, each being marked with the known
graphite or carbonaceous value of same, and the method of taking tracings from
any of these and the metal to be tested, upon an unglazed porcelaine or other acid
proof tablet such as J, and the partial immersion of such tablet and tracings in a
glass beaker or other suitable vessel such as K, containing either of the solvents
Iterein provided according as the test may be for carbon or graphite, and the

page_text: manner of determining the graphite or carbonaceous value of the tested metal by
comparison of the said tracings after the said immersion and washing, substantially
as herein described and shewn.
Dated this 2nd day of October 1895
GEO. THOS. HYDE.
1, Broad Street Buildings, London, E.C., Agent for the Applicant.