Stahl

“ When the carbon has been put in, the retort is closed. The molten metal absorbs the alloy, and the product is Bessemer steel. In fifteen minutes pig iron can be transformed into ingot steel. The invention made possible the use of steel in the construction of bridges, high buildings, and ships. It made this age of the world the Age of Steel. ”

“ I see miles of smoking chimneys where steel is made for all these uses in unimaginable quantities. And spanning the prismal chasm I see a series of great steel bridges, multiplying as I look, seeming to cast themselves in air across the void like cobwebs. But reflect! We have not yet discovered the way to make this steel. Unless we find it quickly we shall fail that unborn host. It cannot get across; if it did it could not live. The iron bridge cannot bear its weight. Nor can the world be prepared with iron. ”

“ I wish to call the attention of the meeting to some of the peculiarities which distinguish cast steel from all other forms of iron, viz., the perfectly homogeneous character of the metal, the entire absence of sand-cracks or flaws, and its greater cohesive force and elasticity, as compared with the blister steel from which it is made,—qualities which it derives solely from its fusion and formation into ingots, all of which properties malleable iron acquires in like manner by its fusion and formation into ingots in the new process ”

“ Castings and Forgings.—There are two distinct ways of making the steel objects actually used in the arts, such as rails, gear wheels, guns, beams, &c., out of the molten steel made by the Bessemer, open hearth, or crucible process, or in an electric furnace. The first is by “steel founding,” i.e. casting the steel as a “steel casting” in a mould which has the exact shape of the object to be made, e.g. a gear wheel, and letting it solidify there. The second is by casting it into a large rough block called an “ingot,” and rolling or hammering this out into the desired shape. ”

“ Steel is, technically, an alloy of iron and carbon. The point is to have the carbon added to the iron in just the right proportion to make the kind of steel that you may happen to want.
“Bessemer—he was an Englishman, too—invented a converter to put carbon back into iron, that is, to make iron into steel.
“When it comes to telling you about steels, I can’t do that to-day; there are too many kinds.
“You may not know it, William, but you are living in the age of steel. Industry depends on iron, for almost all the tools in the world are made of steel. ”

“ But steel of cementation, however carefully made, is never quite equable in its texture. Steel possessing this latter quality is made, by fusing bars of blistered steel, in a crucible placed in a wind furnace. When the fusion has been completed, the liquid metal is cast into small bars or ingots, which are known in commerce by the name of cast steel. Cast steel is harder, more elastic, closer in texture, and capable of receiving a higher polish than common steel.
7. Steel is also made directly from cast iron, or at once from the ore. ”

“ The steel, after having been forged, is soft, like iron, and to give it the requisite degree of strength under the uses to which the tools or instruments are to be exposed, it is hardened. The process by which this is effected is called tempering, and the degree of hardness or strength to which the steel is brought is called its temper, which is required to be higher or lower, according to the use which is to be made of the particular instrument. ”

“ Born and raised in a city of mills, he had, from the age of fourteen, played his little part in the making of steel. For three summers and at every other available hour he had toiled at steel. Bare to the waist, brown, heat-burned, perspiring, he had dragged at long bars, raking away at steel bars, but recently formed by rushing, crashing rollers, that were still smoking hot. Other hours he had spent on the gridiron. The one helped the other. Struggling with steel, he had become like steel himself, hard, elastic, resisting. ”

“ It is a wonder that grows as you watch it and yet it seems so simple. To see that steel, of tremendous strength and hardness, drawn through a tiny hole as if it were molasses candy—and yet it may have a tensile strength of two or three hundred thousand pounds to the square inch. ”

“ Steel is a product, or, perhaps, more accurately, a species of iron, refined of some of its grosser elements, intermediate in the amount of its carbon between wrought and cast-iron, and tempered to a hardness which enables it to take a cutting edge, a toughness sufficient to bear a heavy strain, an elasticity which adapts it for springs and other articles requiring resiliency, as well as a susceptibility to polish, which makes it useful for ornamental and artistic purposes. ”

“ Semi-Steel.—If in the process of puddling or decarbonizing cast iron the process be stopped at a particular time, determined by indications given by the metal to an experienced eye, an iron is obtained of greater hardness and strength than ordinary iron, to which the name of semi-steel, or puddled steel, has been given. The principal difficulty in its manufacture is that of obtaining uniformity in the product, homogeneity and solidity throughout the entire mass. ”

“ Alloy steels have come into extensive use for important special purposes, and a very great increase of their use is to be expected. The chief ones are nickel steel, manganese steel, chrome steel and chrome-tungsten steel. The general order of merit of a given variety or specimen of iron or steel may be measured by the degree to which it combines strength and hardness with ductility. ”

“ Cast steel is used for many of the same purposes as cast iron, but more particularly for those purposes where castings of great strength are required. Wrought iron is forged into various shapes for special purposes, and is rolled into bars, plates, beams, rails, and structural shapes. Extra hard steels are used for tools, hard steel for piston-rods and other parts of machines, medium steel for rails and guns, and the mild and soft steels for beams and structural purposes. ”

“ The top part which contains the pipe is cut off and goes back to the furnace to be remelted. It is termed “discard.”
The big steel makers themselves shape most of their steel into such finished products as rails, plates, rods, and wire. Some of it is by them reduced from the ingot into intermediate “blooms,” “billets,” “bars,” etc., and sold in this form for the manufacture of axles, drop forgings and the hundreds of products which we each day see. ”

“ Its glare lights up the countryside for miles around, and the hissing and roaring of the molten iron, or rather of the steel groaning in its birth throes, forms a fitting accompaniment. It is a sight that once seen will never be forgotten. ”

“ The grand distinguishing trait of steel, to which it owes all the qualities that make it valuable for the uses to which no other metal can be put, is homogeneity due to fusion. Wrought iron, while having similar chemical qualities, and often as much carbon, is laminated in structure. ”

“ Now in the series of operations, the blast-furnace, puddling and crucible processes, through which the iron passes from the state of ore to that of crucible tool steel, it is so difficult to detect just which are the conditions essential to excellence in the final product that, once a given procedure has been found to yield excellent steel, every one of its details is adhered to by the more cautious ironmasters, often with surprising conservatism. ”

“ The introduction of Krupp steel, or nickel, for armor plates, a few years ago, called attention in a popular way to the fact that for certain purposes pure steel—that is, iron plus a certain quantity of carbon—was not as useful as an alloy of steel with some other metal. An alloy was a great improvement over ordinary steel or iron plates used in warfare; but in the more peaceful pursuits, as well as in warfare, certain alloyed steels, such as chrome steel, tungsten steel, and manganese steel play a very important part. ”

“ When the steel made from such iron is wrought into a tool and ground, the edge is uneven, serrated, softer in one place than another. This amounts to a fatal defect in those articles where great and uniform hardness is required, as in screw-taps, wire-drawers, plates, dies, and stamps for coining and engraving. It is evident, as the carbon is introduced from the surface, that there will be less in the middle than at the outside of the bars; thus the steel is not of a uniform character. ”

“ Cut off from Sweden and the world, the Republic must learn to make steel for itself; and, by aid of Chemists, she has learnt it. Towns that knew only iron, now know steel: from their new dungeons at Chantilly, Aristocrats may hear the rustle of our new steel furnace there. Do not bells transmute themselves into cannon ”

“ A German engineer proposes to combine hard ingots, or blocks of steel, in the process of casting, with laminæ of soft steel or wrought-iron, in such a manner that the latter, in undergoing the rolling process, may assume an internal position, thus combining a certain amount of elasticity, ductility, and toughness, in the interior, with a hard exterior to withstand wear and abrasion. ”

“ The iron people of course could make a steel in their own way from wrought iron, melted again and carbonized,—fine, cutlery steel, very hard and trustworthy,—but you could not dream of making rails by the [118] millions of tons from that kind of steel. ”

“ Steel for guns and armor is made in the open-hearth furnace where the quality of the metal may be regulated to a nicety. Gun tubes are cast in vertical molds and during the cooling of the ingot it is subjected to pressure so as to prevent segregation and the forming of “pipes.” Pipes are cavities that are liable to form in the center of the ingot due to contraction during cooling. Steel, as we have learned, is not pure iron, but an alloy, and the various constituents have different temperatures of solidifying, consequently they exhibit a tendency to [324] segregate. ”

“ He picked it up and examined it closely. “Not a flaw. And real steel—the best steel on earth—and I forged it! But how?” He paused, a puzzled look overspreading his face. “How shall I tell them I heated it? What good will one forging do with no means of forging more?”
“Oh, well!” he murmured, at last, “I’ll tell them, anyway. And now,” dropping the connecting-rod in his pocket, “the next thing is something else. I wonder what it will be!”
[71]
He left the forge-room and walked cautiously toward the sheet-metal press. ”

“ Of recent years a special quality of steel for tools called "high-speed" steel has been produced, mainly by the addition to ordinary cast steel of a small percentage of tungsten. The advantage of this is that, within certain limits, this does not soften with heat, and it is, I can assure you, a great invention in war-time, when a nation is straining every nerve to turn out guns and shells as fast as possible. ”

“ For common cutlery, files, shovels, picks, battering-tools, and many such uses it contests the market with open-hearth steel; and while many engineers now specify that their structural shapes, plates, beams, angles, etc., must be of open-hearth steel, there are many eminent engineers who see no need for this discrimination, they being satisfied that if their requirements are met the process by which they are met is a matter of indifference. ”

“ Nor is steel so liable to depreciation in the hands of an inexperienced artisan; as the degree of expansion is not more, in the large proportion of steel mixture, than a loss of strength equal to 41⁄2 per cent, by heating and cooling gradually. The loss in the mixture containing less steel is 71⁄2 per cent. The specific gravity of the two is in proportion.
The frequent welding and re-rolling of iron is of the most beneficial tendency, the elongation of the fibres being highly advantageous; for, a fibrous piece of iron may be compared to a wire rope, the more strands the greater tenacity ”

“ This is an outline of the controversy about the differences which should be expressed by a name, between tool steel and structural steel. In tool steel there is an almost infinite variety as to quality. The best is a high product of practical science, and how to make the best seems now, as hinted above, a lost art. It has, besides, a great variety. These varieties are only produced after thousands of experiments directed to finding out what ingredients and processes make toward the desired result. ”

“ However the steel is made the ingots are reheated and either hammered under a powerful steam hammer or pressed in an enormous hydraulic press. This greatly improves the quality.
The steel can then be rolled into plates, bars or whatever form may be required.
The finer qualities of steel such as are used for making sharp tools are made in quite another way. Instead of being made from crude iron by taking out the carbon, the materials are the finest qualities of wrought iron and charcoal which are mixed together in the correct quantities and melted in a crucible. ”

“ Under this condition of things the gun-constructor finds himself called on to select from cast iron, from wrought iron, and from steel. Having regard to the work which the rifling has to perform, and to other considerations, steel is clearly the metal that one would desire to employ for the central tube. As regards the hoops, one would not be inclined to suggest cast iron, and there remain, therefore, only wrought iron and steel. ”