STEEL.

850

STEEL.— Acier, French; Stahl , German. Few manu-factures have undergone more important changes, andmade more rapid strides within the last twenty years,than that of steel. Indeed the changes, not only inthe modes of manufacture, but also in the propertiesof the metal, have been so great that it has becomeextremely difficult to define what is the meaning ofthe term steel. The chief characteristic of the metaltermed steel twenty years ago was its property ofbecoming hardened by heating and plunging intocold water, and its almost sole use was for makingedge tools. Modern modes of manufacture have soenormously increased the quantity and decreasedthe price, while at the same time they have intro-duced so many new varieties of the metal, that itis now used far more extensively for other purposes,such as railway bars, castings, and plates, than it isfor the older manufacture of cutting tools. This hasled to the extension of the use of the term steel tovarieties which no longer accord with the old defini-tion, and it becomes necessary to try to find a newone. This is exceedingly difficult, because the usageof practical men has sanctioned the application ofthe term to alloys which have many of the proper-ties of wrought iron, and are entirely devoid ofone quality that used to be considered the genericcharacteristic of steel. Scientific writers have endea-voured to draw a distinction between iron and steelbased upon inherent properties, while practicalmanufacturers and users have by common consentcome to apply the terms according to the mode ofmanufacture. With the object of settling the nomen-clature of iron and steel an International Committeewas appointed at Philadelphia by the AmericanInstitute of Mining Engineers. The Committeeconsisted of Mr. I. Lowthian Bell , M.P., Dr.Hermann Wedding, Professor Tcnnek, ProfessorAkermann, M. Gruner, Mr. A. L. Holley, and Mr.T. Egleston; and they resolved upon the followingrecommendations:—

I. —That all malleable compounds of iron, with itsordinary ingredients, which are aggregated frompasty masses, or from piles, or from any form of ironnot in a fluid state, and which will not sensiblyharden and temper, and which generally resemblewhat is called wrought iron, shall be called weld-iron.

II. —That such compounds, when they will fromany cause harden and temper, and which resemblewhat is now called “puddled steel,” shall be calledweld-steel.

III. —That all compounds of iron, with its ordi-nary ingredients, which have been cast from a fluidstate into malleable masses, and which will notsensibly harden by being quenched with water whileat a red heat, shall be called ingot-iron.

IV. —That all such compounds, when they shallfrom any cause so harden, shall be called ingot-steel'.

Siemens, when, speaking upon this point inhis Presidential Address to the Iron and SteelInstitute (1877), remarks: “The nomenclature hereproposed is entitled to careful consideration fromthe eminence, for both theoretical and practicalknowledge, of the gentlemen composing the com-

mittee ; but I apprehend that, for common use, thedistinctions desired to be drawn are too manifold.Moreover, the lines of demarcation laid down runthrough materials very similar, if not identical intheir application, where a distinction in name wouldbe extremely difficult to maintain and awkward todraw. Take, for instance, railway bars from ingot-metal, which are usually specified to bear a givendead load without deflecting beyond certain limits,and to resist a certain impact without rupture. Thematerials answering to these requirements containfrom -2 to - 6 per cent, of carbon, depending in a greatmeasure upon the mode of production, and upon theamount of admixture of phosphorus, sulphur, silicon,and manganese. But inasmuch as the quality oftempering is chiefly due to carbon, part of the railsdelivered under such specification might have to beclassified as ingot-iron, and part as ingot-steel. TheCommittee omits to define the degree of hardeningwhich it considers necessary to bring a materialwithin the denomination of ingot-steel; it is wellknown, however, that the temper depends upon theexact temperature to which the metal is heated beforebeing’plunged into the refrigerating medium, and alsoupon the temperature and conductivity of the latter,and that ingot-metal with only - 2 per cent, of carbon,when plunged hot into cold water, takes a certainamount of temper. The question of the amountof import duties payable in foreign countriesupon metal occupying a position near the proposedboundary line would also lead to considerableinconvenience.

“ Difficulties such as these have hitherto pre-vented the adoption of any of the proposednomenclatures, and have decided engineers andmanufacturers, in the meantime, to include underthe general denominations of cast steel all com-pounds consisting chiefly of iron, which have beenproduced through fusion, and are malleable.

“ Such a general definition does not exclude fromthe denomination of steel materials that may nothave been produced by fusion, and which may becapable of tempering, such as shear steel, blistersteel, and puddled steel, nor does it interfere withdistinctions between cast steels produced by differentmethods, such as pot steel, Bessemer steel, or steelby fusion on the open hearth.”

Although the common use of the term steel mayrender it impossible to find a definition that shall belogically correct, the difficulty of forcing into generaluse even so slight a modification of commonly ac-cepted terms qs the classification proposed by theCentennial Commission is so great, that it is pro-bably better to define the body by its mode ofmanufacture than to attempt to introduce newterms for some products that are now commonlycalled steel, in order that others may be classifiedunder this head in a logical manner, based upon aconsensus of properties. If this were done, therecould be little difficulty in agreeing that the term“ steel ” should be retained, as suggested by Whit-worth and Siemens, for alloys of iron producedby fusion having great strength, and always using

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