278 
NATURE 
[May 16, 1912 
THE IRON AND STEEL INSTITUTE. 
ee annual spring meeting of the Iron and Steel 
Institute was held at the Institution of Civil 
Engineers on Thursday and Friday of last week. 
Besides the presidential address, and the ceremonies 
of presenting the Bessemer medal to Mr. Darby and 
the Carnegie medal to Prof. Goerens, of Aachen, the 
meeting had to consider an exceptionally long and in- 
teresting list of papers covering a very wide range of 
subjects, and therefore likely to appeal to both the 
practical and the scientific members of the institute. 
The complaint is sometimes heard among the prac- 
tical members of the institute that there are too many 
papers of a scientific character, and that discussions 
on scientific metallurgy, and more especially on 
‘metallography, are out of place at the institute. Such 
a view is surely unduly narrow, since the ultimate 
benefit of the steel industry must go hand-in-hand 
with the development of those branches of science 
which are more intimately connected with steel. It 
is true, of course, that a discussion on the constitu- 
tion of hardened steel may not be of immediate and 
direct interest to the manager of a rolling-mill, but | 
the fact that there appears to be a ‘“‘corrosion zone” 
even for him the time will come when he must ask 
for scientific guidance in some new difficulty, and the 
value of the aid which can be given him will depend 
upon the accuracy and completeness of our theories 
on the constitution and transformations of steel. 
Even the obvious fact that ‘‘ professors” disagree 
need not alarm the practical man—the “professors ”’ 
only discuss the few outstanding points upon which 
divergences of opinion exist—upon the main body of 
their scientific knowledge they are so completely in 
agreement that they would no more discuss it than 
the multiplication table. Where men are working to 
advance the outposts of our knowledge, divergent 
views are bound to arise, and vigorous discussion is 
needed to sift out the truth, but the practical man 
will make a great mistake if he interprets these dis- 
cussions as implying uncertainty as to the main body 
of the science. 
These considerations have been raised at the recent 
meeting because the entire afternoon of Thursday was 
occupied by the discussion—at times of a vigorous 
character—of scientific subjects, the constitution of 
steel and the nature and mechanism of corrosion 
being the two principal questions. On the former, 
Prof. Arnold, of Sheffield, contributed two short 
papers, which formed the subject of strong criticism 
by both Dr. J. E. Stead and Dr. W. Rosenhain. 
Prof. Arnold cannot yet reconcile himself to the equi- 
librium diagram of the iron-carbon system and to the 
attached nomenclature which has found general 
acceptance by the great majority of metallurgists; he 
points out, with obvious correctness, that the diagram 
in question does not explain the difference between 
the same steel when quenched from a moderate and 
correct hardening temperature, and when quenched 
from an excessively high temperature, which still lies 
in the same ‘‘field’’ of the diagram. That, however, 
is a criticism on the value of such diagrams in 
general, and not on the correctness of the particular 
example, and similar points could be raised concerning 
most of the well-established diagrams. The conclu- 
sion is evident that equilibrium diagrams, although 
they possess a very considerable value in their own 
special direction, cannot tell us evervthing about the 
behaviour of metals and alloys. Stable equilibria, 
which can alone be properly indicated on these 
diagrams, are comparatively rarely met with in metals 
as used in practical work, and the equilibrium 
diagram must therefore be regarded as a basis for 
the study of those more complex conditions which arise 
NO. 2220, VOL. 89] 
| diminished. 
_ concerned. 
when meta-stable and labile conditions have to be 
considered, 
The subject of corrosion was dealt with in three 
papers, one—on the influence of carbon on the cor- 
| rodibility of iron—by Mr. C. Chappell and. two, on 
the mechanism of corrosion and on the corro- 
sion of nickel, chromium, and_ nickel-chromium 
steels, by Messrs. J. Newton Friend, J. Lloyd Bent- 
ley, and Walter West. The results obtained by the 
first-named author indicate that an increasing pro- 
portion of pearlite in rolled, annealed, and 
| “*normalised’’ steels causes increasing corrosion up 
to that concentration at which the steel consists entirely 
of pearlite, while an increase of carbon beyond that 
point appears to cause a reduction of corrosion, but 
only one hyper-eutectoid steel has been studied in the 
paper. In quenched steels, on the other hand, a 
continuous increase of corrosion appears to accom- 
pany increasing carbon-content. 
The paper on the mechanism of corrosion by Dr. 
Friend and his collaborators is particularly interest- 
ing, as some rather unexpected sources of error in 
corrosion tests carried out in tanks of still water in 
the laboratory are indicated. These errors arise from 
around any piece of corrodible metal immersed in 
water, and throughout this zone there is an oxygen 
concentration gradient; if now the specimen under 
test is placed close enough to the walls of the vessel 
to allow these walls to lie within the ‘corrosion 
zone,’’ then the rate of corrosion will be apparently 
In the case of bright surfaces of pure 
iron, the radius of the corrosion zone appears to be 
approximately equal to the linear dimensions of the 
specimen, so far as small laboratory specimens are 
In their study of the corrosion of nickel 
and chromium steels, the same authors suggest that 
the corrodibility of such steels is affected by two oppo- 
site factors; the galvanic action between such sub- 
stances as cementite in ordinary carbon steels 
and the complexes containing nickel and chromium 
in the alloy steels on the one hand, and 
the more corrodible ferrite on the other, tends 
to increase with the addition of such metals as 
nickel or chromium, but this tendency to increased 
| corrosion is counteracted by the fact that the presence 
| These two factors 
of these incorrodible substances themselves affords a 
considerable mechanical protection against corrosion. 
are differently affected when 
acceleration tests are made in acids, so that these 
become untrustworthy for alloy steels. The most 
striking positive result obtained is the resistance of 
chromium steels to sea-water corrosion, and the authors 
| consider that the ‘‘application of chromium steels in 
the construction of ships would be justified on this 
ground alone.” 
A particularly interesting and somewhat novel 
feature at the present meeting was formed by a group 
of four papers dealing with the ancient metallurgy 
of iron, both in the East and in England. Prof. T. 
Turner describes the ‘‘ham bones” found in the 
neighbourhood of Walsall, in Staffordshire, and dis- 
cusses their probable mode of origin, while Sir Hugh 
Bell presents an account of a bloom of Roman iron 
found at Corstopitum (Corbridge), the investigation 
of this material by Prof. Louis and Dr. Stead being 
described. The conclusion appears to be established 
that this mass of iron is built up of small blooms 
obtained by a ‘‘direct’’ process from the local ore. 
The purposes ascribed to the object as found vary 
from a stake anvil to a battering-ram. Mr. H. G. 
Graves contributes an interesting note on the early 
use of iron in India, describing some of the large 
masses of iron utilised in the construction of certain 
