|The Modules of This Link Hub|
|This Science Module Hub leads to some more information about the 1870 "steel revolution" linked to names like Bessemer, Siemens, Martin, Thomas and so on. These modules are not all that scientific; I just will not be very careful to avoid scientific words or the occasional equation. What will be covered is:|
|1. The Kelly - Bessemer process
Yes! Bessemer wasn't quite alone with his invention. One William Kelly actually came up with the idea a bit earlier.
|2. The Thomas - Gilchrist Process
Why is silica acidic? And quicklime basic? And what does that have to do with phosphorous removal and the Thomas process?
|3. The Siemens - Martin Process
Mostly a few more pictures.
|The picture below shows a contemporary (around 1890) "poster" with implementations of all the processes mentioned (and more). You can far better appreciate it in a large size format.|
|What did Bessemer et al. Know About Iron and Steel?|
|What did Bessemer and the others know about iron and steel? Or, asking more generally, what was public knowledge about the making of iron and steel, the relation between properties and composition / microstructure, and how all that fits together?|
|There is no simple answer. The scientists, for example, learned more and more about
the composition - property relations but the practitioners, the people actually
making iron and steel, wouldn't listen to them for the usual mix of reasons.
They didn't understand it, had learned something else that they liked better,
and so on. Most important, however, was the simple fact that all these
"theories" did not give them any good clues for making better steel.
That hasn't changed all that much. Steelmakers in the second half of the 20th centuries, for example, did now pay a lot of attention to phase diagrams, thermodynamics, kinetics, detailed analytics and so on, the stuff despised by their 19th century brethren, but would not listen to anybody telling them about dislocations and all the other defect stuff, fracture theory, not to mention quantum mechanical stuff relating to solids, for exactly the same reasons given above. And these are good reasons! I, personally, once spend several months on analyzing one grain boundary in silicon in all its eclectic beauties. The process engineers I supervised 10 years later made something like five zillion (1012 - 1014 to be correct) grain boundaries in silicon every day - they could not possible be interested in the details.
|Worse, people within either group - scientists
and engineers - were fighting each other tooth and nail about who was right.
Almost invariably, all of the still better known ones were right about some
important issue and dead wrong about others. It was a bit worse than today but
not entirely different; the great Verhoeven
- Wadsworth jousting tournament gives a good example
To top all that, entrepreneurs like Bessemer prided themselves on not knowing much about iron and steel as will become clear in the respective modules.
|All in all, there
was no general knowledge about the making of iron and steel etc. in the second
half of the 19th century. The situation rather resembled a steamy smelly swamp,
sprouting all types of weird plants and teeming with life that fed on each
other and the plants. Some survived and grew to mighty organisms.
It is impossible to do justice to all the people involved in a major way, the events and accidents that spurred on progress, and the interrelations of all this. Instead I give you simplified tables containing a few of the (for me) more interesting points as a function of time here.
|Iron, Carbon and Steel|
|350 BC||Steel is especially pure iron||Aristotle (Greek)||Aristotle didn't know what iron is either, of course|
|1722||Steel is dirty iron||R. A. F. Réaumur||Yes! Good-bye Aristotle.|
|1770||Manganese in iron is important for making steel.||T.O. Bergmann (Sweden)||Correct up to a point. Manganese
oxide in the ore made smelting easier.
Completely wrong with respect to the difference between iron and steel but believed by many for some time.
|1781||"Plumbago" (meaning carbon) turns iron into steel.||T.O. Bergmann (Sweden)||T.O did get it first. He just didn't know what carbon is and confused (like everybody else then) with lead.|
|1782||Diamond is carbon||Lavoisier||Carbon is an element. First recognitions of elements and a table - with many errors.|
|1786||Plumbago is carbon - like diamond and graphite. Lead is not carbon.||G. Monge,||and C. A. Vandermonde plus C. L. Berthollet, all French. Finally the "nature " of carbon is established.|
|1801||Manganese and carbon make steel||Gazeran (French)||Typical French compromise|
|1819||Aluminum makes (at least) wootz steel special||Faraday||Completely wrong but Faraday made up for that later and in many other respects|
|1821||Silicon is just as important than carbon||Boussingault (French)||No.|
|1830's||There are several forms of carbon relating to steel and cast iron||J.B. Karsten (German)||Karsten recognized correctly graphite, dissolved carbon and carbides - but assumed many kinds ("polycarbides") like FeC, FeC2, Fe2C3, Fe2C. He missed the only real one (Fe3C). He corrected himself 1846|
|1840||You need (unspecified) "steely" ores to make steel instead of iron||Le Play (French)||No. Some ores are better than others from some process but all could work|
|1860's||Nitrogen (in conjunction) with carbon is "it".||M.E. Frémy (French)
|No. Nitrogen can harden iron but there is no "nitrogen steel"|
|1860's||It's carbon - and other stuff and processing.||E.Gruener (French)||Steel is somewhere between relatively
pure carbon-lean wrought iron and carbon-rich cast iron but whatever carbon
concentration it is - steel is defined by properties.
The voice of reason. Steel is not something uniquely defined by one special composition. True but not overly helpful
|1883||It's cementite||???||Recognition that there is only one carbide: Fe3C called cementite|
|1897||First iron - carbon phase diagram||W. Roberts-Austen||First phase diagram but not quite correct before about 1900.|
|What by Whom When and Where|
|1830's||Attempt at a quick tests for carbon concentration||Berthier (France)||Good start but didn't quite make it.|
|1840||Steam hammer invented||J. Nasmyth||Far more force than water-powered hammers with possibility to fine-tune power and stroke depth.|
|1862||First working tests for carbon concentration||V. Eggertz (Sweden)||A color test based on ideas of J. Liebig (German) who perfected the principle for or organic substances|
|1864||First manual with impact "Metallurgy: Irons and Steel"||J. Percy (English)||The first time a handbook containing "theory" was even noticed by practitioners.|
Books and Other Major Sources
Invention or Discovery?
History of Carbon
Early Metal Technology - 2. Silver and Lead
Leda and the Swan
Antique Texts Concerning Iron
Swords and Symbols
The Verhoeven - Wadsworth Jousting Tournament
Steel Revolution. 1. The Kelly - Bessemer Process
10.5.3 Making Steel after 1870
Smelting Science - 1. Furnaces
11.3.2 More to Pattern Welding
Antique Texts Concerning Crucible Steel
Steel Revolution. 2. The Thomas - Gilchrist Process
12.2.6 Experimental Tests of Old Steel and Swords
Steel Revolution. 3. The Siemens - Martin Process
Medieval and Modern Texts Concerning Crucible Steel
Smelting Science - 2. Charcoal Technology
Early Metal Technology - 1. Gold
The Cyprus Copper and Bronze Industry
© H. Föll (Iron, Steel and Swords script)