METALS. 



499 



cheaply, steel directly from pig-iron. It is 

 known as Berard's, and has been adopted at 

 one steel- works in France, and is now receiv- 

 ing the attention of English manufacturers. 

 The principal points of the process, as set 

 down in the Mechanics' Magazine, are as fol- 

 lows: 



1. The employment of gas acting at once as a 

 calorific and reacting agent in purifying the iron by 

 a partial purification before throwing on prejudicial 

 bodies, such as sulphur, phosphorus, arsenic, etc. 



2. The being able to employ iron of a secondary 

 quality, to obtain steels for certain special purposes, 

 such as rails, tireSj etc. 



3. By the combined action of air and gas being 

 able to act alternately by means of oxidization and 

 reduction in keeping the waste at a minimum ; and 

 by decarbonization and recarbonization regulate at 

 will and with certainty the nature of the product to 

 be obtained. 



4. Organizing a plant which shall permit of work- 

 ing under the most economical circumstances. 



In carrying out these principles, the first point has 

 been to secure a good gazogene. This has been 

 effected by making an incandescent bed of coke at a 

 high temperature traverse the gases. The decom- 

 position of the tar and steam is rendered complete, 

 and there is no trace of carbonic acid, while, to in- 

 crease the production of pure gas, particularly hy- 

 drogen, a jet of superheated steam is introduced, 

 which aids at the same time to carry off the gases. 

 The iron is run in a liquid state into the movable 

 bed of the converting furnace. Two descending 

 tuyeres, one on each side of the furnace, and hav- 

 ing a divergent direction, are introduced into the 

 metallic liquid, so as to cause each portion of the 

 metal to come under the action of the current, which 

 provokes a violent ebullition and produces a natural 

 mechanical puddling. A simple arrangement allows 

 the proportion of air and gas to be varied during the 

 operation. When air is in greater proportion, the 

 reaction is of course oxidizing, and it is reducing^ if 

 the gas is increased beyond a certain point. During 

 oxidization the temperature is considerably raised by 

 the combustion of the carbon contained in the iron, 

 the silicum, manganese, and a small quantity of the 

 iron. The sulphur and phosphorus are transformed 

 into sulphuric and phosphoric acids, which may be 

 partly volatilized or may enter into the scoriae. Dur- 

 ing reduction, the oxide of iron alone is reduced. 

 The silica combines with the oxide of manganese and 

 the other bases in order to form silicates, which con- 

 stitute the scoriae of the bath. 



The operation takes from an hour to an hour and 

 a half, and the results of frequently-renewed tests 

 toward its close determine the point of decarboniza- 

 tion of the metal, and the instant at which this should 

 be arrested, in order to obtain the quality of steel 

 desired. 



Chrome Steel. The Iron Age contains an 

 account of a visit to the chrome steel-works in 

 Brooklyn, L. I. The company claim that they 

 have introduced the only great improvement 

 in crucible steel made in many years, and that 

 their process insures perfect uniformity and 

 homogeneity these remarks applying espe- 

 cially to their high-grade tool-steel. They 

 use American iron for some kinds of steel, and 

 foreign iron for others, after refining it, the 

 details of the refining process being kept 

 secret. The writer says : 



We saw the Norway bars cut up and charged into 

 the crucibles, into which the powdered preparation 

 of chrome is also introduced, they say, to the extent 

 of 5 per cent. This chrome-ore is mined near Bal- 



timore, and contains protoxide of iron, magnesia, 

 alumina, no silica, and, when pure, 60 per cent, of 

 oxide of chromium. The crucibles are closed with 

 covers and put into the melting-furnaces, of which 

 there are two, an 8-pot ordinary furnace and a 24-pot 

 Siemens gas-furnace, which latter is a very substan- 

 tially-built and successfully-working structure. The 

 Siemens furnace shows an economy of 50 per cent, 

 in fuel over the old style of melting furnace in these 

 works. The gas is led underground into the fire- 

 brick regenerating chambers of the furnace proper, 

 situated to the right and left of the combustion-cham- 

 bers, in which the pots are set, and underneath 

 which the furnace is open, to avoid trouble in case of 

 removal of pots, and to give access for repairs. Hav- 

 ing valves outside of the heated portion regulate the 

 flow of gas and air. Sturtevant blowers, making 

 2,200 revolutions per minute, noiselessly, are used 

 for furnishing blast to the reheating furnaces. The 

 crucible-room is covered by sectional brick arches 

 held by clamps, and in it, by the combustion of the 

 gas and air, an intense white heat (blue) is created, 

 which soon melts the metal and effects the " reduc- 

 tion," as it is termed here. Meanwhile, the iron 

 ingot-moulds have been placed in upright position 

 near the furnace, but below the working-floor, so 

 that their top comes about on a level with it. _ The 

 workmen stand ready with bars to lift off seriatim 

 the sections of the arch. One seizes and lifts out a 

 crucible with the tongs ; another knocks off the coyer 

 and skims the top of the metal with a tool which 

 looks more like a drum-major's stick than like a 

 dipper, while a third proceeds to the operation of re- 

 fining, or whatever the operation ought to be termed, 

 for its nature is kept secret. All one can see is, that 

 some powdered substance is carefully weighed and 

 poured out of a cup, fastened to a handle, upon the 

 top of the metal and stirred in, producing a trifling 

 combustion and some spluttering of fiery shooting- 

 stars, with increase of light from the metal in the 

 crucible, whereupon the contents of the pot, liquid as 

 water, are emptied into the mould, and the crucible 

 rolled away to cool. But all these operations do not 

 occupy more time than it takes to describe them. The 

 crucibles used here are made in the Jersey City Cru- 

 cible-Works, and last three heats. Being made of 

 graphite, the probable absorption of carbon in the 

 metal has been recognized and carefully considered 

 by the chemist. The ingot very quickly sets. We 

 eagerly examined its surface, and found that it was 

 perfectly regular, compact, smooth, solid, without 

 seams, or pipes, or flaw ; no sinking in, nor rough- 

 ness, nor imperfect metal to be seen on top. 



The expenditure of fuel is about three tons of coal 

 to one ton of steel. The present capacity of produc- 

 tion is about 1,500 tons per annum ; it is contem- 

 plated, however, to erect a Martin furnace beside the 

 crucible furnaces, which, with the additional train 

 of rolls, would give a much larger capacity. As a 

 test of toughness, we were shown a five-eighth inch 

 square bar, twisted cold until it looked like a cable, 

 also a turning-lathe shaving, forty to fifty feet long. 

 Dynamic tests of this steel have been made by David 

 Kirkaldy, in London, also at West-Point Foundery, 

 which latter showed as the highest strength of twelve 

 specimens, 198,910 Ibs. ; lowest strength of twelve 

 specimens, 163,760 Ibs. ; average of all the speci- 

 mens, 179,980 Ibs.; or say, 180,000 Ibs. per _ square 

 inch, which is one-third more than Percy gives as 

 the highest tensile strength attained in steel. 



The Corrosion of Iron. Mr. William J. Mc- 

 Alpine discussed this subject in a paper read 

 before the American Society of Civil Engi- 

 neers, and gave the following as some of the 

 teachings of his personal observations and ex- 

 periences especially with relation to water- 

 pipes: 

 Cast-iron, to resist corrosion to its greatest exten 4 



