Unfortunately this quote includes some errors re: wrought iron
54ball said:In composition, wrought iron differs from cast iron and steel in two important features, viz.: (1) In having had removed, as an essential of its manufacture, the greater part of the five elements usually contained in iron. In this respect it is near the composition of mild steel. (2) In containing, as a result of the process of manufacture, a quantity of slag (usually called cinder) which surrounds each iron crystal in a thin sheath, and preserves the identity of the crystal as a fiber when a bar of wrought iron is elongated by rolling or hammering. In this respect it differs from steel, which is crystalline and without much slag.
Both iron and steel are crystalline in structure. The silicate slag is/was introduced during the refining process from pig iron to wrought iron - they used sand as a flux. The silicate slag generally shows up as inclusions in the iron and not as a sheath around each iron crystal. But WI also comes in at least three grades and the amount of slag varies considerably. The poorest grade was single wrought used for barrel hoops, wagon wheels, etc. Double wrought for finer products such as fences and bridges, and triple wrought was used for making fine guns parts, knife tangs, and similar items. It was then case hardened for wear resistance
The chief properties of wrought iron are as follows, viz.:
(a) It is very malleable and ductile, and can be readily forged, particularly when heated.
Depends on how readily one means and it must generally be forged at a near white heat. Lower the heat much and it will start to break apart. FWIW - I've been forging WI since the late 1960's and have the same experience as many other long time makers who use WI.
(b) It cannot be cast, as it is fusible only at a very high temperature (about 2800° F.), and merely becomes pasty at the usual furnace temperatures, though because of this quality it is readily united by welding.
Well it can be cast by getting it the proper high heat. Iron ore itself melts at the same temps. Also WI with a fairly high carbon content (see below) will melt at lower temps.
(c) It cannot be hardened, due to lack of carbon.
This is one of the mythconceptions re: WI. Dependent on how well it was manufactured and the number of heats used (the more heats causes the carbon to burn off) and despite what many sites state, WI may contain as much as .60% carbon although generally contains about .02-.03% carbon. Rik Furrer of Door County Forgeworks http://www.doorcountyforgeworks.com/Welcome.html, is one of todays most experienced smiths and an acclaimed expert on period iron and steels and has noted that WI may contain higher carbon and still be WI and not steel, since the differentiation of the two has more to do with the process than carbon content alone. It can also be hardened via case hardening
(d) If pulled apart, the fracture shows a fibrous break.
True one of the best methods when scrounging WI to make sure it is to cut a piece in about half the thickness and bend it to see the structure - if fibrous you've got WI
Wrought iron gets its name from the fact that it may be wrought into various shapes readily under the hammer; also it is called malleable iron in England, because of its great malleability, but it must not be confused with malleable castings, also called malleable cast iron or merely malleable iron in America.
Partly true - the name may also come from the process of working pig iron into WI.
Etymology
The past participle of Middle English werken (“to work”), from Old English wyrcan (past tense worhte, past participle geworht), from Proto-Germanic *wurkijanÄ…, from Proto-Indo-European *werǵ- (“to work”). Cognate with wright (as in wheelwright etc.), Dutch gewrocht, archaic past participle of werken (archaic past tense wrocht, archaic past part. gewrocht), Low German wracht, archaic past participle of warken (archaic past tense wrach, archaic past part. wracht).
While wrought iron and mild steel resemble each other, there are certain distinct advantages of wrought iron which cause it to be retained for some uses. Among its advantages are (1) it welds better than does steel, Generally yes but again only with with the proper high heat. As for the steel some will weld as good as WI when at the proper heat - mistake is most problems with steel are too high a heat and trying to beat it together. When at the right heat whether steel or WI a few taps of the hammer is all that is needed - too much heat/beating breaks the bond. Many modern smiths as well as old time smiths use/used a press rather than a hammer for welding(2) lasts longer when exposed to weather or to water, (3) is better to resist shock and vibration (fatigue), in use, and (4) its fibrous structure arrests fracture, as its breaking is in the nature of a gradual tearing, which often gives warning of a dangerous stress, while steel breaks suddenly. The last three are generally true but again the differences will depend on the type of steel in comparison. As for WI tearing I've seen it burst into bits especially at low temps and not all steel breaks suddenly - it all depends on various factors such as carbon content, manufacturing method, temp, etc.
Among the disadvantages of wrought iron are, (1) its elastic and tensile strength are lower than those of steel, Agan it depends on the type of steel in comparison and the quality of the WI (2) and its production is more costly.True and there is only one modern manufacturer of WI http://www.realwroughtiron.com/ . On the other hand there are sources of various qualities of old salvaged wrought iron such as bridges, wagon wheels, grain storage facilities, etc.
Read more: http://chestofbooks.com/crafts/mec...-Wrought-Iron.html#.VE7RTldZ7ng#ixzz3HOFFUqCk
Period documentation mentions "shot out" barrels not rusted out. Since true wrought iron is somewhat softer the barrels may have truly worn out before rusting out. :hmm
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