Branding iron

“ There are many modifications of these general rules and methods, and it may be necessary in certain cases, such as the ironing of braids stiffened with media other than gelatine or water soluble materials, to employ other methods, but they are generally peculiar to the plait used and of a purely ephemeral nature. In some factories box irons are used, heated by patent fuel, others are warmed by gas and electricity, but the general convenience of the fire-heated pad causes the old fashioned iron to retain an almost universal supremacy. ”

“ Manufactured irons differ very greatly amongst themselves. For one kind is tenacious in its nature, and this is the best; one is of medium quality: another is brittle, and this is the worst. Sometimes the iron, by reason of the excellency of the ore, is wrought into steel, as to-day in Noricum. From the finest iron, too, well wrought and purged from all dross, or by being plunged in water after heating, there issues what the Greeks call στόμωμα ”

“ But since modern methods of manufacturing have been adopted, tons of metal, which would have been classed as iron if judged by the cooling test, are at present known as mild or soft steel.
Steel may properly be defined as an alloy of iron with carbon, the latter not exceeding 1.8 per cent; the materials are completely fused and poured into molds, allowed to cool, and then rolled into shape. In the processes of making wrought iron the materials are only partly fused and are not cast into molds, but are taken out of the furnace in a soft, pasty condition suitable for immediate working. ”

“ It is so highly 75refined that it can hardly be called steel at all but is often called “open-hearth iron” or “ingot iron.” It is probably the purest iron on the market in commercial quantities to-day. While in the chemical laboratory iron of considerably greater purity can be made, for a commercial product this is remarkably pure, seldom containing more than 1⁄4 per cent of elements other than the metal, iron. ”

“ Ordinary cast iron, while strong and hard enough for many purposes, still is brittle by reason of the large proportion of carbon and other impurities which it contains. These impurities may be burned out in the puddling process, and the nearly pure iron thus obtained, called malleable or wrought iron, has a toughness enabling it to resist far greater strains than cast iron can stand. Intermediate between the two irons, and containing one per cent of carbon, more or less, is still another product, steel, which may be made even more tenacious than wrought iron, or even harder than cast iron. ”

“ That is, as soon as a vessel costing millions of dollars leaves the docks, she enters into active competition for a place on the junk pile."
The greatest improvement that can be imagined in the iron situation will be in the discovery and use of alloys or mixtures of iron with other materials. Steel, the strongest of all forms of iron, is an alloy of iron and carbon, and for various purposes these are further mixed with nickel and silicas. Many other alloys have been discovered within the last few years, and each makes possible new uses for iron requiring greater strength. ”

“ One has no difficulty in realizing that these flakes, which cut in every direction through the metal, make it structurally weak, especially toward a sudden blow.
No. 1d shows a typical section of wrought iron cut lengthwise of the rolled bar. It will be noted that, as in photomicrograph No. 99b, there are no graphite flakes.
In the process of wrought iron manufacture practically all of the carbon of the original pig iron is burned out, leaving little besides the iron itself and some viscous cinder or slag. ”

“ Open-hearth iron is practically pure iron, having no constituents or slag inclusions which materially affect its properties.
2. Wrought iron, for all practical purposes, is pure iron 86except for its content of slag. It is the only one of the iron family which does normally contain slag.
3. Neither open-hearth iron nor wrought iron contains carbon in appreciable quantities.
4. The distinguishing and active element of the steel family is carbon. With increase of carbon the hardness of the alloy increases as does its tensile strength, but the ductility (elongation or stretch) decreases. ”

“ With such a volume of weakening constituents and particularly with the graphite flakes cutting through and separating the iron grains as the photomicrographs show, can one wonder that cast iron is fragile—more so than steel or wrought iron? ”

“ Pure iron like pure gold is homogeneous, but unlike gold it is rarely pure. If gold be kept in a melted condition a sufficiently long time, all extraneous matters may be burnt away, but if iron be kept in a hot state too long it will be burnt away itself. Pure iron appears to be ductile, but pure iron will not melt. To form cast-iron, a quantity of carbon must be mixed with the pure iron. If the quantity of carbon be less in amount, steel is the result. ”

“ We say that the iron made by the ancients was in reality a variety of what we now term wrought iron, for it fulfilled three of the principal requirements for wrought iron, viz., it was not necessarily melted during production, it was a malleable metal, and it contained cinder or slag, but practically no carbon. ”

“ Steel has no fiber and for this reason it cannot be split as was the wrought iron bar shown in the illustration of page 92.
It will have been noticed that only small amounts of iron can be refined at one time. This, indeed, has been the unfortunate part of wrought iron manufacture, for it may readily be seen that production of any such material in lots as small as a quarter ton results in labor costs which are almost prohibitive in these days of machine-made goods. Not only is the output of a furnace small but much skill and judgment are necessary for the production of a high grade product. ”

“ Moreover, there is yet a most great benefit to the kingdom in general by the sow iron made of the ironstone and Roman cinders in the Forest of Dean, for that metal is of a most gentle, pliable, soft nature, easily and quickly to be wrought into manufacture, over what any other iron is, and it is the best in the known world ”

“ Billy looked at him questioningly.
“That was rather technical, wasn’t it, Billy? You see, I was talking to a technical man. Just between you and me, meteoric iron comes down from the sky, from what we call shooting stars. Sometimes large pieces are found. I suppose that much of it falls into the sea. It is the purest iron that has ever been found.”
“What about magnetic iron?” asked Dr. Crandon. “Where does that come from?”
“At the present time,” answered Mr. Prescott, “most of it comes from Sweden and Norway. It makes the best kind of steel. ”

“ From the above it is seen that all sorts of cast iron can be produced ranging from the extremely hard, high cementite, white irons with low silicon content down to the very soft gray irons which result mainly because of higher silicon content and slower cooling.
The white irons are more or less unstable as is shown by the decomposition through which the hard, white iron castings become “malleable” by annealing as was told in Chapter XII which discussed Malleable Cast Iron. ”

“ Pig-iron, or, as it is sometimes called, crude iron, being saturated with carbon and oxygen, and containing also a portion of scoria, is too brittle for any other purpose than castings. Many of these, such as stoves, grates, mill-irons, plough-irons, and kitchen utensils, are commonly manufactured at blast furnaces, and in many cases nearly all the iron is used for these purposes. In such cases, the metal is taken in a liquid state, from the hearth, in ladles. ”

“ Case-hardening of iron, is a process for converting a thin film of the outer surface into steel, while the interior remains as before. Fine keys are generally finished in this way. See Case-hardening.
So great is the affinity of iron for carbon, that, in certain circumstances, it will absorb it from carburetted hydrogen, or coal-gas, and thus become converted into steel. On this principle, Mr. Macintosh of Glasgow obtained a patent for making steel. His furnace consists of one cylinder of bricks built concentrically within another. The bars of iron are suspended in the innermost, from the top ”

“ Whereas iron has a value in itself considered. It fells the forest, tills the soil, annihilates time and distance, and underlies the whole economy of domestic life; for our readers will bear in mind that steel is only another form of iron.
[Pg 19]
The value iron acquires under the hammer is something wonderful. It is said that a bar of iron worth $5 is worth $10.50 when made into horse-shoes, $55 when made into needles, $3,285 made into penknife blades, $29,480 in shirt buttons, and $250,000, in balance springs of watches. ”

“ On the application of heat in furnaces, constructed for the purpose, the charcoal unites with the oxygen of the oxide, reducing it to the metallic state, and escapes in the form of carbonic acid; and the lime, if the ore be argillaceous, unites with the clay, forming a kind of glass, which floats on the melted metal. When the iron is suffered to run into moulds, prepared for its reception, it usually takes the name of pig iron.
Manufacturers distinguish cast iron by its colour and other qualities. The white cast iron is hard and brittle, and can neither be filed, bored, nor bent. ”

“ The sheet iron intended for this manufacture is refined with charcoal instead of coke, subsequently rolled to various degrees of thinness, and cut into rectangles of different sizes, by means of a shearing-machine driven by a water-wheel, which will turn out 100 boxes a day, or four times the number cut by hand labour. The first step towards tinning, is to free the metallic surface from every particle of oxide or impurity, for any such would inevitably prevent the iron from alloying with the tin. ”

“ At once the founding of iron became an important art. It was not long, however, before the fact was established that by further treatment the cast iron would be transformed into wrought iron. To-day the production of cast iron in the blast-furnace is the first step in the manufacture of iron and steel. ”

“ This iron melts at a lower temperature than white iron and becomes more fluid, contracts less and contains fewer cavities; it fills the mold well, the edges of a casting are short, and the surface smooth, convex, and covered with carburet of iron. Gray iron is the only kind suitable for making castings which require great strength, such as cannon. White iron is very brittle, resists the file and chisel, and is susceptible of high polish, the surface of a casting is concave, the fracture presents a silvery appearance. ”

“ Some kinds are broken up to be used as foundation for roads; others are granulated by being run into water, and so made into cement. Over in Germany, where the ores are rich in phosphorus, they grind up the linings of the furnace to make phosphatic fertilizers for the farmers.”
“Then,” said Dr. Crandon, “the making of iron involves the use of chemistry, doesn’t it?”
“It certainly does,” answered Mr. Prescott; “from the chemical composition of ores to the finished product. We are learning a great deal just now from the chemists about steel alloys. ”

“ Almost all the comforts and conveniences of civilized life are obtained by iron. You may imagine, then, the condition of the Papal States, when I state that iron is all but unknown in them. It is about as rare and as dear as the gold of Uphaz. And why is it so? There is abundance of iron in our country; water-carriage is anything but expensive; and the iron manufacturers of Britain would be delighted to find so good a market as Italy for their produce. Why, then, is iron not imported into that country? ”

“ Unlike the modern Bessemer, open-hearth, and other steel products which are reworked, i.e., rolled, forged, etc., cast iron is a comparatively old alloy dating back over several centuries. It cannot be rolled, forged, or otherwise reshaped, so its final form must be given to it at once by pouring or “casting” the molten metal into a mold. Its castings serve exceedingly well in the hundreds of places for which they are adapted. They are comparatively cheap, can be readily duplicated in small or large quantities, and those from the softer grades of cast iron may be machined easily. ”

“ NATIVE OXIDE OF IRON.
Iron stands first in usefulness of all the metals, for railways, bridges, ships, and a thousand other purposes; it can be both cast and wrought, having that peculiar property, the capability of being “welded,” that is to say, of softening while hot to such an extent that when two pieces are made white hot and laid together, a few blows of the hammer will cause them to unite into one piece, and it is by means of this most useful quality that large masses of wrought iron are produced, such, for instance, as anchors and cranks for steam-boats. ”

“ No one knows just when, with increase of carbon, steel ceases to be steel and becomes white cast iron. There is no definite dividing line either in chemical or physical properties. The changes are extremely gradual throughout the scale. Aided by the microscope, modern physical chemistry has disclosed the fact that alloys of iron with carbon “freeze” from molten to solid condition according to two different laws. ”

“ Pure iron is never obtained commercially, the metal always being mixed with various proportions of carbon, silicon, sulphur, phosphorus, and other elements, making it more or less suitable for different purposes. Iron is magnetic to the extent that it is attracted by magnets, but it does not retain magnetism itself, as does steel. Iron forms, with other elements, many important combinations, such as its alloys, oxides, and sulphates. ”