526 



METALLURGY. (!RON, STEEL.) 



yet desirable, and means were sought of adding 

 it directly in tar, petroleum, etc., and mixtures 

 of those substances with solid bodies, such as 

 burned dolomite. An efficient method of doing 

 this has been applied by Mr. John Henry Darby, 

 of the Brymbo Steel Works. He brought fluid 

 steel into intimate contact with solid carbon, 

 when the carbon was rapidly absorbed by the 

 steel. Supported by this experiment, he founded 

 on it his patented process by which fluid steel 

 can be carbonized by filtration through pieces of 

 carbon. By this process, in conjunction with 

 the basic process, Mr. Darby produces from phos- 

 phoric raw material a steel, which, with any 

 wished-for percentage of carbon to upward of 

 0-9 per cent., contains only small traces of other 

 bodies, and is consequently distinguished from 

 other open-hearth steel by its exceeding tough- 

 ness.. The process was soon exclusively em- 

 ployed at Brymbo for the harder steels, and was 

 introduced into the Bessemer works of the Phoe- 

 nix Company of Laar, near Ruhrort, on the 

 Rhine, in 1889. Special advantages are claimed 

 for this process by Mr. Thielen, managing di- 

 rector at Ruhrort, in each of the three methods 

 for the production of steel the Thomas, the 

 Bessemer, and the open-hearth. 



In a paper on the " Inspection of Materials of 

 Construction in the United States." George H. 

 Clapp and Alfred E. Hunt give a series of tables 

 showing the changes in requirements that have 

 taken place in the -last ten years in engineers' 

 specifications. These specifications indicate a 

 tendency to give a decided preference to open- 

 hearth steel, a gradual lowering of the require- 

 ments in tensile strength, and an increase in 

 elongation and reduction of arsa. Tempering 

 tests have been introduced in recent specifica- 

 tions, and steel that has been heated to a dull 

 cherry red, and quenched in water at from 60 

 to 80 P., according to the different specifica- 

 tions, must bend 180 around a pin varying from 

 one to two diameters without a sign of fracture. 



The gradual substitution of steel for wrought 

 iron for many purposes, notably for rails, plates, 

 beams, and other structural shapes, has made it 

 desirable and possible to cast and roll steel in 

 very large masses as compared with the smaller 

 piles that were worked and welded when wrought 

 iron was used. Many advantages in economy 

 are gained by making steel ingots as large as 

 can easily be handled. Among the more im- 

 portant results of the increase in the size and 

 weight of ingots are improvement in quality 

 and the greater ease with which the product of 

 any plant can be handled in and out of the pit 

 when large ingots are used. A machine is de- 

 scribed by S. T. Wellman which is intended to 

 do all the work through the processes from tak- 

 ing the ingot from the car on which it comes 

 from the converting house to depositing it on 

 the table in front of the rolling mill. All the 

 valves controlling the movements of the ma- 

 chine, as well as operating to open the furnace 

 doors, are worked by one operator, who rides on 

 the machine. 



The conclusions of Mr. C. B. Dudley, drawn 

 from his investigations of the wearing qualities 

 of steel rails in service, and communicated to 

 the American Institute of Mining Engineers, in 

 1878 and 1881, were that a mild steel is less 



liable to fracture, and, if properly made, less 

 liable to crushing or disintegration in the track 

 than a harder steel ; and that the wearing power 

 of steel in rails does not increase, but diminishes, 

 as hardness increases. Criticising his work after 

 the lapse of ten years, he concludes that if he 

 had it to do over again he would determine 

 the sulphur in the rails ; that in view of the 

 better understanding of the influence of that 

 element the silicon limit would be raised some- 

 what; that the influence of chemical composi- 

 tion was made more and that of the method of 

 manufacture less prominent than the facts would 

 warrant; and that the comparative method, 

 rather than an absolute one, should be used as 

 far as possible in determining the difference 

 between good and poor rails. Otherwise than as 

 regards these criticisms, the author sees no rea- 

 son to change his original main conclusion that 

 mild steel is safer for rails and for other con- 

 structive purposes, and also gives better wear, or 

 loses less metal under the same traffic, than harder 

 steel. Experiments are now making on the wear 

 of steel tires. A large number of experiments 

 have been made with alloys used as bearing* 

 metals, from which instructive information may 

 be drawn as to the relation between wear and 

 the chemical and physical properties of metal. 

 From all the experiments the author deduces 

 that that metal which will suffer the most dis- 

 tortion without rupture will wear best ; that an 

 increase in tensile strength will add to the 

 wearing power of the metal : and that, of two 

 metals which have the same tensile strength 

 and the same elongation, the one which is finer 

 in granular structure will wear the slower. The 

 relation and interaction of these three variables 

 is an unknown field. The best that can be said 

 at present is that, with the light we have, the 

 highest tensile strength, accompanied by the 

 highest elongation and the finest granular struct- 

 ure, are the physical properties which will proba- 

 bly give the best results in actual service when 

 the metal is subjected to wear, and that that 

 chemistry which will give these results in the 

 finished product, whether in alloys, in steel, or 

 in aluminum, is the best. 



In his paper on "Steel Rails," considered chem- 

 ically and mechanically, read at the meeting of 

 the Institute of Mechanical Engineers in Shef- 

 field, England, Mr. C. P. Sandberg attributed 

 the greater durability of the first Bessemer rails 

 made in Sheffield to the hammered blooms and 

 slow-running mills of early days. Hardness is 

 no doubt a virtue in railway lines, and may be 

 obtained by work; but it can also be obtained 

 chemically. By the latter means, however, 

 other desirable features may be put in jeopardy. 

 In respect to silicon, a different composition was 

 required for steel that was to be used in bridge 

 and ship work from what went into that intended 

 for rails. In the discussion on mechanical tests 

 which followed the reading of the paper, tensile 

 tests were pronounced undesirable, because costly 

 and of little or no use. The falling-weight test 

 and a test for hardness, together with such light 

 as might be thrown by chemical analysis, were 

 considered sufficient. The tables presented by 

 Mr. Sandberg showed that 4 24 per cent, of sili- 

 con in steel rails gave the best results. 



One of the most interesting developments in 



