admin wrote:He says that *some* was good quality steel, but a lot of armour - even a lot of high status stuff - was made of iron or very low carbon steel. What he told me was that they were surprised to find very little correlation between high status pieces and good quality steel - apparently there was an even spread of material across the board and across a wide period. Also, heat treated armour seems to have been in the minority (because of course not much armour was of high enough carbon content to be heat treated anyway).
Yes we know that a couple of the most famous makers were regularly producing heat-treated carbon steel armour by the mid-15thC, but that armour was very much in the tiny minority in the grand scheme of things. And by the 16thC the amount of heat-treated armour seems to have reduced, for whatever reason.
leonardo daneluz wrote:Modern steel (pure iron isn´t common, what we know as iron is usually iron +0,1% carbon or some more) has a lot of beautiful alloying elements which aren´t present before, say, 1880. .
leonardo daneluz wrote:Heat treating little pieces of modern steel is easy mostly because modern steels are designed to be easily heat treated... and because we can learn the "hardening´+ tempering" combination from a lot of sources. I still never found a reliable description of deliberate tempering until the XVII cent.
bigdummy wrote:leonardo daneluz wrote:Modern steel (pure iron isn´t common, what we know as iron is usually iron +0,1% carbon or some more) has a lot of beautiful alloying elements which aren´t present before, say, 1880. .
Well we know for a fact this isn't true, since Wootz steel relies on the trace elements of vanadium, molybdenum et al as you already acknowledged in this thread. Just because they didn't know what these elements were does not mean they were not introducing them into the steel intentionally, following old processes which were only partly understood, like the Norse using the bones for phosphorous or the Indian smiths using the special mineral laden clay to make their forges.
For those who unlike Leonardo and Matt aren't aware of this, an article on the importance of these 'impurities' in wootz
http://www.tms.org/pubs/journals/JOM/98 ... -9809.html
leonardo daneluz wrote:Alloying elements in wootz are related to nucleation of carbides. There is no probe AFAIK that impurities were deliberately added to wootz. Nucleation of carbides is enhanced by these elements but occurs without them too and there were many wootz varieties without them. There are lots of modern knifemakers making their own "wootz" which looks very similar to the ancient.
Can you provide any probe that wootz was intended to be hardened by quenching at all?
Alloying elements like phosphorus are related to cold work hardening. They have nothing to improve heat treatment or making it easier.
Full temper of a big thick sword with ancient material is difficult, to say the least. You´ll chance cracks and you´ll get warping in no easily solved ways. Could be done? yes , but it wouldn´t be the safest choice, slack quenching, fine perlite structures were a much safer way and most blades tested show exactly that. Adn design can be combined to obtain something perfectly useful.
Design in many, if not most , of the oakeshott typology puts use envelope of the steel in the blade well into the elastic range for perlitic steel which behaves exactly as it was full tempered martensitic steel (Which is one of the weird and counter-instinctive things in steel)
My point is that an ancient sword in times when the cycle "hardening + tempering" wasn´t a widespread knowledge had a huge difference in performance with anything you can make in your backyard with an old car spring, a coal forge and burnt oil. Strictly speaking about mettalurgy and no design involved.
Once proper tempering was widespread (you have pointed a nice source in the XVI cent. I had only found some in the XVII) you can get different things and certainly that happened.
Can somebody be sure that an armour or sword of tempered martensite wasn´t tempered by heating it in a grinding wheel instead of deliberated tempering? Tempering for simple carbon steel starts at 200C or less.
more simply said:
wootz: alloyed to favour carbide nucleation
your source for Norse steel making: Alloyed to favour cold working.
Modern steel: alloyed to be easily hardenable and to cope fragility induced by sulphur and phosphorus.
bigdummy wrote:What you apparently perceive as ideology in me on this subject, is simply this: I see a strong persistent myth, left over from Victorian era like so many are, that metalurgy was crap in the Medieval world, armor and swords were made of 'pig iron' and so on, and since it appears to be incorrect, I like to point that out. There is an opposite myth that everything from long ago was better, which I also shoot down from time to time (though not often around here*).BD
* I can however, point you to places where I do
leonardo daneluz wrote:I think we all agreed on that and can resume moving forward. My point specifically in this matter (ancient metalurgy) is that we don´t ussually get in which direction the ancients worked. We tend to think in a linear progress, kind of "Age of Empires", where you develop one thing as a step into another and then into another. It doesn´t work that way. It could be "pig iron" and still that means nothing viewed as an isolated event. It takes a view of the whole picture to figure what that really means.
It is always easier to see the big picture in regard to politics, philosophy or art, because those leave a lot of archaelogical records. But small trades don´t.
"Technology in the XXI century was so backwards that their computers and cars couldn´t work properly for more than a few years without serious malfunction. Can you imagine that? They could put a man on the Moon but not make a car last 5 years"
leonardo daneluz wrote:Thearos wrote:So is there any possibility that a chopper could shear through mail ?
From a period metalurgical point of view: Yes, indeed, just as shown there. A posibility.
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