574 



METALLUKGY. 



tion purposes, 43,598 votes were cast for, and 

 8,673 against it. It was accordingly ratified. 



At the municipal election in Boston, on the 

 15th of December, Hugh O'Brien, Democrat, 

 was re-elected mayor, by a vote of 26,672 to 

 18,092 for Clark, Republican. ' The Board of 

 Aldermen consists of 6 Republicans and 6 

 Democrats, and the Common Council of 31 

 Republicans and 41 Democrats. On the license 

 question, the vote was: yes, 19,603; no, 10,- 

 284. 



METALLFRGY. Iron and Steel. In his final 

 report on the condition in which carbon exists 

 in steel, made to the Institution of Mechanical 

 Engineers in January, 1885, Sir Frederick Abel 

 announced that the results of the experimental 

 work appear to warrant the following con- 

 clusions in regard to characteristics recogniz- 

 able by chemical examination, which are ex- 

 hibited by different portions of one and the 

 same sample of steel presenting marked physi- 

 cal differences consequent upon their exposure 

 to the hardening, annealing, or tempering pro- 

 cess: 



" 1. In annealed steel the carbon exists en- 

 tirely, or nearly so, in the form of carbide of 

 iron, of uniform composition, evenly diffused 

 through the mass of melted iron. 



u 2. The cold-rolled samples of steel exam- 

 ined were closely similar in this respect to the 

 annealed steel. 



" 3. In hardened steel the sudden lowering 

 of the temperature from a high red heat ap- 

 pears to have the effect of preventing or ar- 

 resting the separation of the carbon, as a defi- 

 nite carbide, from the mass of iron in which 

 it exists in combination; its condition in the 

 metal being, at any rate mainly, the same as 

 when the steel is in a fused state. The presence 

 of a small and variable proportion of Fe 3 C in 

 hardened steel is probably due to the unavoid- 

 able and variable extent of imperfection, or 

 want of suddenness, of the hardening opera- 

 tion ; so that, in some slight and variable de- 

 gree, the change due to annealing takes place 

 prior to the fixing of the carbon by the hard- 

 ening process. 



" 4. In tempered steel the condition of the 

 carbon is intermediate between that of hard- 

 ened and of annealed steel. The maintenance 

 of hardened steel in a moderately heated state 

 causes a gradual separation (within the mass) 

 of the carbide molecules, the extent of which 

 is regulated by the degree of heating, so that 

 the metal gradually approaches in character to 

 the annealed condition ; but, even in the best 

 results obtained with blue-tempered steel, that 

 approach, as indicated by the proportion of 

 separated carbide, is not more than about half- 

 way toward the condition of annealed steel. 



" 5. The carbide separated by chemical treat- 

 ment from blue- and straw-tempered steel has 

 the same composition as that obtained from 

 annealed steel." 



Microscopic examinations by Messrs. Osmond 

 and Worth, of the Creuset Works, of cast-steel 



skeletonized by dilute nitric acid, have shown 

 that the original distribution of iron and car- 

 bon in the metal was far from uniform, and 

 that the steel is actually made up of small 

 granules of soft iron separated from each other 

 by partitions of another substance containing 

 carbon, which is a carbide of iron. In other 

 words, cast-steel may be said to possess a kind of 

 cellular structure, in which the iron forms the 

 nucleus and the carbide the envelope of the cell. 

 The elementary cells so constituted, or simple 

 cells, are aggregated in groups into so-called 

 compound cells, which are divided from each 

 other in the transparent sections by thin lines 

 which are empty spaces. These lines form in- 

 closed polygons which are of considerable size 

 in cast-steel, but become smaller, and more and 

 more broken and confused, in the metal that 

 has been more or less perfectly forged. As 

 the surfaces of the compound cells, after the 

 action of acid, are represented in section by 

 empty linear spaces, they must in reality be 

 iue to the contact of soft iron masses without 

 the intervention of the carbide, in which case 

 the compound cells are said to be deprived of 

 envelopes. In another direction it is easy to 

 see that the compound cells correspond to 

 what is known as the grain of the steel, or 

 their faces are regions of minimum cohesion, 

 so that the fracture of a bar of steel may be 

 defined as the surface which, in the particular 

 part subjected to the breaking strain, contains 

 the minimum of carbon. These observations 

 apply only to steel that has been slowly cooled. 

 By hardening, the compound cells disappear 

 entirely, the constituent elements remaining 

 being simple cells, but the interposed carbide 

 of iron is much less abundant than in the same 

 steel when annealed; the remainder of the 

 carbide having separated as hydrate, which 

 appears to be uniformly dispersed or dissolved 

 in the mass of the metal. From the point of 

 view of these experiments, forging has nothing 

 in common with tempering in modifying the 

 structure of steel; although the change pro- 

 duced in physical properties is somewhat simi- 

 lar. 



The new Clapp - Griffiths process for the 

 conversion of pig-iron into steel has been used 

 at the works of Oliver Brothers and Phillips, 

 Pittsburg, Pa., with satisfactory commercial 

 results. It has the advantage of requiring a 

 relatively small outlay, and promises, there- 

 fore, to be useful at points where it would not 

 be expedient to establish large works, but 

 where the demand is sufficient to justify the 

 erection of minor furnaces. The converters 

 used in operating the process are stationary, 

 with removable bottoms, each holding from 

 two to three tons. The blast, instead of en- 

 tering through tuy&rea in the bottom of the 

 vessel, as in the Bessemer process, passes into 

 the converter through the sides at some little 

 distance above the bottom. Having thus li 

 tie resistance to overcome, blast at low press- 

 ure, furnished by cheap blowing apparatus. 



