May 15, £902] 
Mr. A. McWilliam and Mr. W. H. Hatfield described an ex- | 
haustive research dealing with the control of the silicon in the 
acid open-hearth bath. The experiments were made in a 25-ton 
furnace at Sheffield. The results detailed, showing the influence 
of the composition of the slag on the elimination of impurities 
from metal under an oxidising influence, seem to point to the 
necessarily very acid slag produced being beyond the point at 
which silicon can be oxidised, for it would appear that not only 
can phosphorus and sulphur not be oxidised in an acid-lined 
vessel in the presence of an acid slag, but that silicon is not 
oxidised to below a certain percentage when the acidity of the 
slag is beyond a certain point. The authors have thrown light 
on a subject still requiring further elucidation, namely, the rela- | 
tion between the composition of the slags and the type of | 
oxidation or even reduction taking place, and they in particular 
have not seen recorded this exact balancing of the composition 
of the slag, so as at will to eliminate or reinstate small amounts 
of silicon and manganese while the carbon continues steadily 
to fall. A well-sustained discussion followed, in which the 
value of the paper was generally recognised. 
Mr. H. Allen described a new system of cooling blast-furnace 
tuyeres in such a manner as to prevent the leakage of water into 
the furnace crucible. The meeting then adjourned until May 8, 
when the secretary, Mr. Bennett Brough, presented the report 
of the committee appointed to ascertain whether it would be 
possible to make the terminology of metallography less com- | 
plicated and more precise. This comprises a glossary of the 
more important terms used by authors of memoirs dealing with 
the subject, with the exact equivalents in French and German. 
Care has been taken to exclude all controversial matter, and, in 
cases where a definition is not quite universally accepted, to 
quote the definition given by its respective author. 
The next paper, by Prof. J. O. Arnold and Mr. McWilliam, 
was of a highly controversial nature. The conclusions arrived 
at in the paper were as follows:—The clear and definite 
constituents of hardened steel are (a) hardenite, Fe,,C, of 
which the whole mass consists, only in the case of 0°89 per 
cent. carbon steel ; (4) ferrite, Fe, which segregates more or less 
tn unsaturated carbon steels in spite of the rapid action of 
quenching ; and (c) cementite, Fes;C, which segregates more or 
less in supersaturated steels in spite of the rapid action of 
quenching. The indefinite portions of hardened steels consist 
in unsaturated carbon steels of hardenite containing more or 
less unsegregated ferrite, or in supersaturated carbon steels of | 
hardenite containing more or less unsegregated cementite. 
Martensite is not a constituent, but a crystalline structure de- 
veloped at high temperatures. [tis marked in saturated carbon 
steels by preferential etching lines, in unsaturated carbon steels 
by strice of ferrite, and in supersaturated carbon steels by strize 
of cementite. The existence of the constituents sorbite, troosite 
and austentite is extremely doubtful. Students of micrographic 
analysis should guard against apparent or false constituents 
really due to optical causes or to obscure polishing or etching | 
effects. The authors’ investigations detailed in this paper have 
been strictly confined to pure iron and carbon steels such as are 
produced in the best crucible practice. The views expressed by 
the authors were opposed by Sir W. C. Roberts-Austen, Mr. 
J. E. Stead and other members. 
Dr. J. A. Mathews’ paper on a comparative study of some 
tow carbon alloys, which was next read, contained the results of | 
a research undertaken in New York by the author as Andrew 
Carnegie research scholar to ascertain the effects of various 
elements upon iron, The elements studied were nickel, chro- 
mium and molybdenum. Prof. Arnold took exception to this 
paper on the ground that no reference was made to his own work 
on the same subject. 
Mr. H. Kilburn Scott presented an elaborate description of 
the iron ores of Brazil. The quality of the mineral and the 
great size of the deposits will, the author is convinced, enable 
Brazilian iron to take a leading position in the market. Some 
valuable additional details were furnished by Mr. H. Bauerman. 
Mr. P. Eyermann, of Benrath, near Diisseldorf, submitted a 
paper describing a proposed method of combining the blast 
furnace and the open-hearth furnace. The novel feature con- 
sisted in the employment of blast-furnace gas in the open-hearth 
furnace, in arrangements for improving the quality of the gas 
and in the application of air nozzles to one of the hearths. 
Mr. Axel Wahlberg, of Stockholm, communicated an im- 
portant paper on Brinell’s researches on the influence of chemical 
composition on the soundness of steel ingots. The percentage 
NO. 1698, VOL. 66] 
| contained in the charge. 
63 
of carbon and the casting temperature, which have hitherto 
been regarded as the agents responsible for the presence and 
position of blow-holes, are to be regarded as exercising a 
secondary influence. The principal cause is the percentage of 
silicon and manganese, and in some cases of aluminium, con- 
tained in the ingot metal at the moment of casting. In the 
discussion, Mr. C. P. Sandberg pointed out that some of the 
results given by Brinell had been anticipated by himself in a 
paper read ten years ago. 
From the investigations recorded in Baron Jiiptner’s paper on 
the sulphur contents of slags, the following conclusions are 
drawn :—If during metallurgical processes a state of equilibrium 
is established between the slag and the contiguous metallurgical 
product under treatment, the sulphur distributes itself between 
| the two in a constant ratio (the coefficient of distribution), the 
value of which is dependent on the composition of the two 
phases under consideration and on the temperature. In general 
the value of these coefficients of distribution increases with the 
basicity of the slags, It increases also apparently with the pro- 
portion of lime and manganous oxide (probably also with that 
of ferrous oxide and zinc oxide) in the slag. In the case of 
alloys of iron, the value of the coefficient of distribution increases, 
and very considerably, with increasing percentages of carbon 
and manganese and with diminishing percentages of phosphorus. 
The influence of the composition of iron alloys on the coefficient 
of distribution increases and diminishes with the increase or de- 
crease of the basicity of the slag. The same law holds good with 
respect to the influence of a higher percentage of lime and 
manganous oxide in the slag. The conclusion contained regard- 
ing the effect of the composition of iron alloys may be explained 
by the supposition that the capacity of manganese, and perhaps 
also that of iron carbide, or at least of iron rich in carbon, to 
absorb sulphur is very low, while, on the other hand, that of 
pure iron and phosphide of iron is very high. These facts show 
that in metallurgical operations in general it is impossible to 
eliminate entirely from the product the whole of the sulphur 
The extent to which desulphurisation 
can be carried depends upon the coefficient of distribution—that 
is, upon the composition of the two phases occurring during the 
process in question. On this account the desulphurisation of 
irons rich in carbon and manganese (ferromanganese and pig 
iron) is more complete than with irons low in carbon and 
manganese, such as those produced by the open-hearth and 
Bessemer processes. In the Bessemer process, the phosphorus 
exercises an additional counter-influence to the desulphurisation ; 
but this appears only to be possible when the phosphorus has 
largely decreased, in which case, however, the carbon and 
manganese have also almost entirely disappeared. In order, 
therefore, to keep down the sulphur to the lowest possible 
margin in iron, which is very low in carbon and manganese, 
there remain only two courses open (since the basicity of 
the slag cannot be increased beyond a certain limit), viz. 
(a) either in the selection of a charge that contains the least 
possible sulphur, consisting of pure iron or of iron that has been 
desulphurised in the mixer; or (4) by repeated removal of the 
old slag and the formation of new slag. In this connection a 
mixer could be employed with good effect, since this not only 
supplies a raw material lower in sulphur, but its use necessitates 
the removal of the mixer-slag and the formation of new slag. 
It is by no means impossible, especially with a falling tempera- 
ture, that a third phase, a mixture of oxides and sulphides, may 
occur in conjunction with the slagand metal. This phenomenon 
seems to occur during certain segregations. 
In a paper on the chemical and physical properties of carbon 
in the hearth of the blast furnace, Mr. W. J. Foster showed 
that by increasing the temperature and diameter of the hearth, 
more carbon would be exposed to the oxides, with proportionally 
less interruption by the gases that are decomposed in the neigh- 
bourhood of the tuyeres ; hence more carbon would be converted 
into carbon monoxide in the hearth per unit of air introduced 
at the tuyeres, and consequently an increased rate of driving and 
economy would be the result. : 
The making of a fixed gas from wood for service in the gas 
engine or in the manufacture of steel is in some localities 
desirable. Mr. James Douglas, of New York, was induced, 
therefore, to give a detailed account of the use of a fixed gas, 
made in a modification of the Loomis gas producer in Mexico. 
The meeting terminated with the usual votes of thanks. The 
autumn meeting of the Institute will be held at Diisseldorf on 
September 2 to 5. 
