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ET me but do my work from day to day
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· Volume IV
No. 6 ..
Story of the Steel Industry
By G. P. BLACKISTON
Iron and Steel Expert
iants 0? This i delicate white
HE giants of to-day-are sons of The 450 steel works scattered through
Tubal Cain. This is the age of out the United States represent a total insteel. From the delicate em- vestment of over $442,000,000, and pay
broidery needle in the white $103,000,000 annually in wages. These hand of a woman, to the one hundred- figures cover only the actual production ton gun, belching forth death to distant of steel in its crude form, a process in battleships, the most important tools of which man has rapidly been superseded civilization are made of steel.
by the marvelous and all but human maFar-leaping steel bridges, towering chines. The magnitude of the industry steel sky-scrapers, deep steel tunnels un- in its entirety, representing a capital of der the earth, steel greyhounds of the billions and employing millions of wageocean, steei engines running more and earners, may therefore be imagined. more swiftly across continents on steel tracks—the potent alloy of iron makes
Definition of Steel them all possible.
Steel is so closely allied, in certain parThe steel industry has made an almost ticulars, to cast and wrought iron, that unbelievable number of millionaires; it a complete and satisfactory definition of is the index to the prosperity of the whole it is almost impossible. Though differpeople; it marks also the place of a na ing considerably in their physical and tion among its peers.
chemical properties, they are all alloys of The United States makes more than iron and carbon, the essential difference one-third of the world's production of among them being in the percentage of steel—fifteen millions out of a total of carbon. thirty-six and one-half millions of tons; Wrought iron usually contains less it is the richest and most prosperous than 0.30 per cent of carbon, and is not among the nations. The two statements materially susceptible to hardening when are complementary. Germany comes sec- suddenly cooled. It invariably contains ond, with an annual production of 8,000,- slag and is malleable. It is the product 000 tons; and England third, with 5,- of the “puddling” furnace. 000,000 tons.
Steel usually contains between 0.08 and Copyright, 1906, by The Technical World Company
2.00 per cent of carbon. Although its selling as high as sixty to eighty cents minimum limit extends within the bounds a pound. of wrought iron, it is free from slag. The mixture for melting, consisting of With but few exceptions, steel is capable definite and carefully weighed amounts of hardening and is malleable at some of certain grades of wrought iron, blister temperature.
bar, alloys, and scrap, according to the Cast or pig iron contains, as a rule, be- grade of steel desired, is packed in pots tween 2.00 and 4.00 per cent of carbon, but is not malleable at any temperature.
From these definitions, therefore, it is seen that steel is the alloy between cast and wrought iron. Various Processes Used
To obtain the physical and chemical properties needed for the numerous and almost totally different uses to which steel is put, several processes are employed in the conversion of the iron, scrap, and other raw materials into steel. The most important of these are the “Bessemer," the
MOLTEN IRON BEING POURED FROM THE MIXER INTO Ladles. “open hearth,” and the "crucible” processes. The first of these, named after its great inventor, the late varying in capacity from 50 to 150 Sir Henry Bessemer, is the method by pounds. These pots are usually comwhich the majority of cheaper steels are posed of plumbago and German clay, almanufactured. Accordingly we find the though in England a clay pot is almost great tonnage of rails, structural shapes, altogether used. The life of the plumshafting, and the lower grades of sheets bago pot varies according to the manner and wire, produced in this way. The open of treatment, the mixture of materials hearth process furnishes the steel for melted within it, and the quality of springs, shovels, the better grades of the pot itself; but on a rough average it wire, forgings, plates, and other articles, might be stated that each can be used in which a higher grade of material than three times. Bessemer is required, yet a grade not so The pots being filled, and a cap placed fine as Crucible. When the highest grade upon each, they are lifted one by one and of product is desired—such as edge and placed in the furnace. cutting tools, surgical instruments, Although the crucible process is one razors, saws, die blocks, etc.—steel from of the oldest, but little advance has been the crucible furnace is utilized.
made in its operation. The furnaces of
to-day and the methods employed, are The Crucible Process
practically the same as those in vogue Crucible steel is made in much smaller during the times of our forefathers in quantities than the other forms of steel, 1789. the endeavor being to obtain quality The furnace proper consists of nurather than quantity. Consequently it is merous holes, varying in number accorda very high-priced steel, the finer grades ing to the size of the furnace. In Amer
It is in this vessel or furnace that the iron is mixed uniformly, previous to being
used in the open hearth steel rurnaces.